American Magazine

The American HORTICULTURAL Magazine

f a II 1969 / volume 48 / number 4 Journal of the American Horticultural Society, Inc.

2401 CALVERT STREET, N.W. / WASHINGTON, D. c. 20008 For United Horticulture . . . The particular objects and b'l!-siness of the. Am.eric~n Horticultural Society are to promote and encourage natIOnal znteTest zn sCIentIfic research and education in horticulture in all of its branches.

EDITORIAL COMJ\llTTEE DIRECTORS MR. VINCENT K. BAILEY DR. FREDERICK G. MEYER, Acting Chairman ____ Washington, D.C. St. Paul, Minnesota MRS. ERNESTA D. BALLARD DR. JOHN L. CREECH ______New Carrollton, Maryland Philadelphia, Pennsylvania DR. CONRAD B. LINK ______University Park, Maryland MRS. JULIAN W . HILL Wilmington, DelawaTe MR. ELVIN McDoNA LD ______New York, New York DR. JOSEPH E. HOWLAND Columbus, Ohio DR. NEIL W. STUART ______Silver Spring, Maryland MR. EDWARD P. HUME Edwardsville, Illinois DR. FRED B. ''''ID;\10YER ______Las Cruces, New Mexico DR. LOUIS B. MARTIN MR. WILBUR H. YOUNGMAN ______Silver Spring, Maryland Denver, Colorado DR. FREDERlCK G. MEYER Washington, D. C. MR. BRIAN O. MULLIGAN OFFICERS Seattle, Washington MR. R. HENRY NORWEB, JR. President MR. FRED C. GALLE ______Pine Mountain, Georgia Mentor, Ohio MR. JOHN M. PATEK First Vice President Rochester, New York DR. DAVID G. LEACH ______:Brookville, Pennsylvania MRS. FRANCIS PATTESON-KNIGHT 1\'{cLean, Virginia Second Vice President and Treasurer DR. LEON C. SNYDER DR. R. C. ALLEN ______Mansfield, Ohio St. Paul, Minnesota DR. NEIL W . STUART Secretary Beltsville, Maryland MRS. FRANCIS l'ATrESON -!\. NIGllT ______McLean, Virginia DR. HAROLD B. TUKEY, SR. Woodland, Michigan Immediate Past President MR. Jm-IN H. WALKER ______Washington, D. C. EARL E. VALLOT Youngsville, Louisiana DR. FRED B. WIDMOYER Assistant Secretary Las Cruces, New Mexico MRS. ELIZAilETH G. EASTIlURN, Executive Director MR. NATHANIEL WHITTIER Washington, D. C. Medfield, Massachusetts DR. DONALD WYMAN Assistant Treasurer Jamaica Plain, MR. GLENN B. EASTBURN, Finance Office ______Washington, D. C. Massachusetts

THE AMERICAN HORTICULTURAL MAGAZINE is the official publication of The American Horticultural Society and is issued during the Winter, Spring, Summer, and Fall quarters. The magazine is included as a benefit of membership in The American Horticultural Society, individual membership dues being $15.00 a year. THE AMERICAN HORTICULTURAL MAGAZINE is devoted to the dissemination of knowledge in the science and art of growing ornamental plants, fruits, vegetables, and related subjects. Original papers which increase knowledge of plant materials of economic and aesthetic importance are invited. For manuscript specifications, please consult the chairman of the Pub­ lications Committee. Second class postage paid at Baltimore, Maryland and at additional mailing offices. Copy­ right © 1969 by The American Hopticultural Society, Inc. FALL. 1969 VOLUME 48 • NUMBER 4

In This Issue

Guest Editorial- "N ational Policy o[ Environmental Protection"- The TVashington P os t ______146

Proteads-A Gardener's Challenge-RoBERT L. EGOLF ______148 Flower Colors and Color Fans-JoHN M. PATEK ______158 My Friends the Penstemons- GLENN VIEHMEYER ______167 Laurel Fig-An Exceptional Shade Tree- JoHN M _ HALLER ______172 Advances in Horticulture- NEIL oW. STUART, Eclilol' Recent D evelopments in Producing More Crops on Straw-Po G. ALLEN 175 Flower Necrosis in Call1eya Orchids- RoGER LAWSON 176 '''Teeds-LoRAN L. DA NIELSON, Editor ' IVin ter ,tV eed Con trol ______--______180 Garden Notes A Great Iris Garden- GORDON BLACKWELL ______183

Ilea vil'ginica-Virginia Sweetspire or Virginian 'Willow- FRED C. GALLE ______186

C al'pentel'ia ca lifomica-MILAN RAFAYKO ______187 H emerocoliis for D ark Patios-A LICE B. SHELDO N ______187 Excerp ts from Pc ter Va n Melle ______166, 171, 174 Book Reviews-CoNRAD B. LINK, Edilol- ______188 Index to Vol ume 48 ______190

EclilO1', FREDERICK G . MEYER IVlanaging EclitOT, ELIZABETH G. EASTBURN

FRONT COVER ILLUSTRATION PTolea cynal'oicles, king protea. Flowers 5 to 6 inches across . National flower of South Africa. PnOTO S . J. LlE8ENBERG, COURTESY, OUTH AFRICAN TOURIST CORPORATION

BACK COVER ILLUSTRATIO N "Laurel de 1<1. India", Ciudad Victoria, Tamaulipas, M ex ico

PIIOTO J OliN ~r. I-l A" FR Guest Editorial

Because the following editorial states so precisely the need for sound leadership and sound policy in the area of environmental legislation, yow' editors present it as a matter of certain interest to all members of the Society.

National Policy of Environmental Protection

The chief question raist'd by President Nixon's creation of a cabinet-level Environmental Quality Council is whether it will be equal to the major tasks which the country faces in this sphere. The destruc­ tion of natural resources and the pollution of water and air have assumed proportions which make drastic action imperative. Many observers fear that even a Council headed by the President and including all the Cabinet heads directly concerned may not be able to reverse the trends which now threaten us . It is not merely a matter of cleaning up the Na­ tion's rivers and attacking the problem of smog, vital as these objectives may be. The country must wake up to the fact that the quality of our living space is seriously deteriorating on a broad scale. Open space is gobbled up for superhighways, airports, factories and suburban developments without much thought of what the consequences will be for both present and future generations. Reckless use of the land strips it of fertiIi ty and at the same time fouls once beautiful and useful streams. The proliferation of pesticides threat­ ens to upset the balance of nature and to leave poison residues tha t may afflict man as well as wildlife. And the spread of urban sprawl, messy industrial areas, j unkyards, billboards and power lines gnvely detracts from the amentities of life.

146 AMERICAN HORTICULTURAL SOCIETY No doubt the public will have a chance to air many views through the Citizens' Advisory Committee on Envirorunelltal Quality which is to be headed by Laurance S. Rockefeller. Nevertheless, the· larger problem seems to be to infuse all governmental pro­ grams 'with a policy of protec ting the environment. Fortunately there is agreement between the White House and leaders on Capitol Hill on the need for legislation that will leave no doubt of the national intention to stop fouling our living space. Senator Jackson, chairman of the Interior and Insular Affairs Committee, has amended his bill to establish a national environmental policy so as to supplement the step the President has already taken. The bill would declare a national policy of preven­ ting and eliminating damage to the environment. It would seek to "assure for all Americans safe, health­ ful, productive and aesthetically and culturally pleas­ ing surroundings"; to attain the widest beneficial use of resources compatible with conservation and protec­ tion of the environment, and the preservation of historic, cultural and natural values. Probably the most significant aspect of the bill is that it would recognize for each person a "fundamen­ tal and inalienable right to a healthful environment" and impose on each a "responsibility to contribute to the preservation and enhancement of the environ­ ment." Every governmental agency would be required to carry out its functions in the light of the new congressional policy that the bill would set up. In the past protection of the environment has been nobody's business. Under this proposed legislation it would become the responsibility of every agency whose activ­ ities have any bearing on the environment. Only experience will point to the precise kind of organization that is necessary. But the enactment of a sound legislative policy, the authorization of research and the provision of adequate trained personnel are certainly essential first steps. Congress should lose no time in su pplemen ting the President's efforts.

The Editors

THE WASHINGTON POST

J une 3, 1969 'i\'ashinglon, D . C.

FALL 1969 147 Proteads- A Gardener's Challenge ROBERT L. EGOLF

Plants of the Pro tea fami ly (Pro­ teaceae) are for gardeners a difficult and challenging group to grow. If they were not, the plants comprising it would be far more common than they are in the gardens of our southern and south­ western states. Instead of being common they are nearly unknown. How many gardeners have seen in this country even a single plant of the family in bloomr This is doubly unfortunate because in the family are numbered some of the world's most spectacular flowering trees and shrubs. The only plant of the family common in Florida is the silky-oak GTevillea TO busta, from Australia; and while this tree is handsome enough in late spring with its large golden trusses of flowers, it is far from being uncom­ monly showy. Two other plants of the DL Ego IJ, a jJh ysician, has degrees Jrom Yall' family occasionally seen in Florida are and Temple UniveTSities and is at jJresent the macadamia nut tree, Nlacadamia working in Student Health at the University integTifolia, and the fire wheel tree, at South Florida, TamjJ!! 33620. H e at ­ StenocG.1·pus sinuatlls, both from Queens­ tributes his ea7'ly inteTest in hOTticultuTe to land, A llstralia. In California the silver a long line at Pennsylvania Dutch faTmil/ g tree of the Cape of Good Hope, Leuca­ ancestoTS on both sides. Since 1962 this in ter­ dendTOn argentell1n, is grown, as well est has been gTeatly stimulated by his friel/d­ as a few leucospermums, the silky-oak, ship with Dr. Edwin A. JH enninger, 0 learin and Hakea. These examples are excep­ in FloTida and wOTld lz07·ticultIl.7·e and a COlt­ tional because in general many mem­ ITibut07' to this magazine. FO'r several years bers of the family resist cultivation, D-r. Egolf's majoT efforts have been diTected especially outside their natural range 10 the intToduction and establishment in and habitat. Fl07'ida of some of the g reatly neglected The natural distribution of the Pro tea wealth of the flora of South Africa, Australia, family is almost entirely confined to the and New Zealand. This article deals ",ith southern hemisphere. Australia, with 35 one aspect of that WOTl: . (In the photo oJ I he genera and 800 species, and South Afri­ authoT, the foliage shown is IllClt of S'le IlO­ ca, with 14 genera and 380 species, are carpus si nll:ttlls, a lJlont 711{' II1ionNI in I/I C the mai n centers of distribution. The lexl.) family is also found in South America, mainly along the western coast, and

148 AMERICAN HORTICULTURAL SOCIETY Brazil extending as far north as Mexico; in Africa (outside South Africa) north to Ethiopia; in Madagascar; and in the Paci'fic from New Zealand through the islands of Melanesia to Japan. In all there are 55 genera and nearly 1200 species in the family. Of these, species in not more than a dozen genera are com­ monly cultivated, mostly in Australia, New Zealand, and South Africa. In the northern hemisphere a number of the hardier grevilleas from Australia, and EmbothTium from Chile are grown in Ireland, Cornwall, and the Scilly Islands, and our Pacific coast. 'Whether any of the Protea family are commonly grown in southern Europe, about the Mediterranean, I do not know, but the climate would appear suitable." A few plants of the Protea family in PHOTO E. E. LORD northern Australia and on the islands Telopea speciosissima, New South north of Australia are found on wet Wales Waratah. Flowers intense red. tropical lowlands or in rain forest. Bu t New South Wales, Australia, near the the majority of the family are character­ coast. istic of semi-arid regions. Proteaceous plants are found in abundance in vVestern Australia, where the annual Grevillea robusta, silk-oak. The com· rainfall may be 10 inches or less, and monest species of the genus in culti· vation. Grown in many warm coun· in smaller numbers in eastern and tries for a street tree, also much northern Australia, with a wetter cli­ grown in pots as a houseplant in the mate. United States and Europe. Produces The SOllth African and Australian attractive golden-yellow flowers in species discussed here grow on deep open heads. Native of eastern Australia. sand or gravel soils of low fertility, usually dry and with sharp drainage. When the surface soil is closely under­ laid with an impervious layer of clay or limestone the plants do not thrive. Acidic soil conditions are a necessity, and nearly tlte entire family is wholly intolerant of lime. In regions where pro­ teaceous plants are in greatest abun­ dance, in both Australia and South Afri­ ca, rain falls in winter; summer is dry and hot. Rain out ·of season is definitely injurious and may cause rotting of the roots. In Australia native banksias left standing as garden plants when land IS

"The Chilean hazelnut Gev'tlina ave llana is grown in England and California, and species of Banksia are grown in Portugal and on the French Riviera. Another prolead, Roupala mac/'ophylla 'Corcovadensis' from Brazil, is cuI tivated in greenhouses in Europe. (Ed.)

FALL 1969 149 Banksia grmulis. Large shrub to tree about 4 0 ft., with whitish tomentose branches. Leaves often 1 fl. or more long. Flower­ spikes 8 to 12 inches long. A striking plant now cultivated in California. Native of Western Australia. PHOTO D OUGLA S ELLIOTT

PHO I 0 L ONGWOOD GARDENS Grevillea petrophiloides, bottlebrush grevillea. Shruh 4 to 5 ft. high, with plume­ like pink flowers. Western Australia.

Hakea laurina, sea urchin tree. A shrub of 10 ft. or more, or a small tree to 30 ft. Flowers red studded like a pin-cushion with creamy white pins. Cultivated in California and, rarely, in Florida. Native of Western Australia.

PHOTO E. E . L ORD

150 AMERICAN HORTICULTURAL SOCIETY cleared and developed usually die if ated with root fungi are compounded artificial watering is begun. For this rea­ for us beca use imported seeds must be son California and the lower southwest sterilized before entry into the country. of our country would appear to be bet­ After germination, seedlings must de­ ter adapted to growing plants of the pend for survival upon a chance and family than Florida or the southeast, unlikely contact with a compatible root where summer rains are the rule. How­ fungus. Lack of a naturally occurring ever, summer rainfall areas exist in symbiotic root fungus explains the dis­ South Africa and proteas are sllccessfully proportionately large seedling losses we cultivated there if special attention is have. given to drainage. Importation of larger es tablished plants is not likely to be successful either. Mycorrhizal Relationships A proteaceous plant of any size will not Why are the plants of the Pro tea tolerate having the soil removed from its family so difficult to grow? In the first roots, and any attempt to move a plant place, production of fertile seed is low, es tablished in the ground is wholly use­ and what there is tends to germinate less. For the most part cuttings root erratically unless absolutely fresh. Seed­ poorly, and the resuhing plants are of­ lings once germinated are difficult to ten weak rooted, misshapen, and unsatis­ es tablish. lVIortali ty in the first year is factory. Plants of the Pro tea family extremely high, usually over 75 per cent, transplant with difficulty, even when in my experience, and often more than container-grown, I have not found any 90 per cent. The seedlings are apparent­ other group of plants half so resentful of ly dependent upon the establishment of disturbance at the roots as these. Almost a root fungus for normal growth and every gardener experienced with these development. They are also extremely plan ts agrees tha t the roots of a pro­ sensitive to damping off. It is difficult to teaceous plant are best left strictly alone. encourage the necessary root fungus There is less unanimity about pruning. while also discouraging the damping off On the one hand we are advised to fungus. lVI ycorrhizal associa tions are of pinch the tips of young plants repeated­ widespread occurrence in the plant ly to obtain a vigorous, bushy growth. kingdom, from pine trees to orchids. The On the other, hard pruning of an estab­ fungi apparently invade the roots of the lished plant is occasionally followed by host plan t, and it is speculated that they total collapse. In this there is much supply enzymes that can break down difference among different species and complex organic materials in the soil genera. For all of these reasons plants of into simple nutr,ients available to the the Protea family cultivated in gardens host. have acquired the evil reputation of When transplanting proteaceous seed­ being in a flourishing condition one day, lings Australian nurserymen advise dis­ and dead the next. L eucadendron ar­ carding plants thM do not have a visible genteum is considered a short-lived, un­ ball of hairy fungus clinging to the dependable plant in California, and yet roots. The yo ung plants do not adapt it is one of the few proteaceous plants well to growing in containers becaus(' available in the nursery trade. the necessary soil microorganisms are In spite of these difficulties, plants of hard to maintain in the enclosed, lim­ this family ca n be cultivated successful­ ited environment of a co ntainer. Soil ly. In their native countries they are the mi croorganisms are very se n ~itive to cul­ ornament of many gardens, and are ac­ tural practices, and the application of knowledged to be worth all the prob­ chemical fertilizers or animal manures, lems th ey bring, and more. In these or even cultivation about the roots of a co untries they even support a cut-flower plant are apt to disrupt an existing industry, and there has recently been balance. It is safest to eliminate such talk in South Afri ca of prohibit!ing the lb ings entirely about proteaceous seed­ export of pro tea seed as an economic lings and plants. These problems associ- measure to protect the flower growers.

FA!.L 1969 151 Culture reused the potting soil, only to have The basic cultural conditions should seedlings appear in 2 or 3 weeks among bc a poor, acidic soil, sharp elra i nage, Lhe other plants. Usually, however, if anel minimum disLurbancc. \Vilh sllch plants arc going Lo come [rom pro­ contrary plants one must be: willing LcaceOllS seed thcy will appear within a Lo continually try new things. At one month. Sceds of a l1umber of pro­ time or another I have used nearly teaceO llS genera have resisted every every imaginable germination technique effort of mine to germinate them, but I including cold stratification, sulfuric am inclined to attribute these failures to acid, boiling water, mechanical scarifi­ aged seed. Recently a technique of ger­ cation, and complete removal of the minating difficult seeds on fine wire seed coats, and for media, vermicu­ screens under a continuously moving lite, sa nd, moistened layers of tissue pa­ stream of water was described. This I per, and regular potting soil. On several have not yet tried but it might hold occasions I have kept seeds in soil under promise for the pro teas. The technique what seemed ideal conditions for more rests on the evidence that there are than a year, given up in disgust and wa ter soluble substances in the outer

PIIOTO P. H. BRYDON 8allll"s;(I speciosa. Shruh ultimately PHOTO DOUGLAS ELLIOT r ahout 10 ft. high. Leaves 8 to 12 Dryanlira formosa. An erect shrub inches long, more or less white to- attaining 8 to 15 ft., with tomentose 1l1entose heneath, stems also white branches. Leaves 4 to 8 incItes long. woolly. Infloloescence ahout 5 inches F~ower heads I to 1]12 inches in long with silvery bracts and brhdlt diameter, silvery villous hairy. Re­ yellow stamens. Cultivated in C~Ii­ lated species now cultivated in Cali­ forllia. Native of Western Australia. fornia. Native of Western Australia.

152 AMERICAN HORTICULTURAL SOCIETY coats of some seeds that inhibit germina­ bers. If a half dozen seedlings are tion, and that these can be removed by potted you are likely to be wiped out. running water. 1£ you can get 25 or 50 seedlings the Keeping seedlings alive, once germi­ chances are better that some will sur­ nated, is something else again. Austra­ vive. I have 'One two-year-old Protea lian genera seem to me a little easier obtllsifolia alive that represents an origi­ than tbose from South Africa. Seedlings nal seedling group of about 55. This that survive the first year become easier kind of experience, frequently repeated, to handle, partly because weaklings have can discourage the most enthusiastic been eliminated. I have had somewhat gardener. better success germinating seed in ver­ In countries where the plants are miculite than in soil, but seedlings widely grown a common trick is to germinated in soil in individual con­ germinate seeds in sojl taken from tainers are a little more likely to survive beneath an established plant of the beca use the initial pricking out is by­ same kind, thus insuring inoculation passed. The best way to get plants from with the proper soil fungus. This, seedlings is to play the game with num- unfortunately, we cannot generally do. If plants can be grown in one locality through two or three seed gener­ ations they are prone to become progres­ sively more adapted to local conditions and easier to keep alive. In spite of problems I am working at pl'esent with plants and seedlings of Macadamia, Stenocarpus, Grevillea, Pro tea, Isopo­ gon, Leucospej·mwn.. Hakea, and Banksia. It is my fond hope that at least a few species in each of these genera and others will eventually prove adaptable to growing condi tions in Florida. In point of ornamental value the plants of the Protea family are compara­ ble to nothing else. The plants are often striking in habi t and foliage, occasional­ ly even approaching the bizarre, and the large flowers, borne in profusion, are often intensely colored and uniquely fashioned. Among the largest genera in number of species and those most com­ monly cultivated are the following: Banhsia: 50 species of shrubs and small trees confined to Australia. Banksi­ as are typically large shrubs, somewhat angular and stiff, wi th upright cylindri­ cal inflorescences in shades of yellow to brick rec!. The flowers when faded PIIOTO DOUGLAS ELLIOTT harden into a woody cone. Banksias, as Pro tea repens, sugar bush_ A spread­ with most of the rest of the family, ing shrub, up to 9 ft. high. Leaves thri ve best on a diet of studied neglect. leathery. Flowers with involucral Dryandm: 50 species of shrubs and scales glabrous, sticky, deep rose small trees, mostly in Western Australia. pink or pale cream. Cultivated in California. Native on mountain slopes The flowers are in pom-poms at the ends from the Cape Peninsula to Grahams­ of the bran ches, rather resembling a town, South Africa. thistl e or a spiclery chrysanthemum. Dry-

FALL 1969 153 They are commonly known as fire bushes in reference to their masses of in tensely red flowers. The Chilean Embothriwn coccineurn, when estab­ lished, C::1 n t@Jerate 20 degrees of frosL, making it one of the !l::1rdiest of the family. They are much grown in Irish gardens and to some extent in the Puget Sound area of \'Vashington and coastal gardens of Oregon and northern Califor­ nia. Grevillea: 230 species in Australia, Tasmania, and New Caledonia, ranging from low shrubs to large trees. This is the la·rgest genus in the family, and is very diverse in habit, foliage, and flower. Grevilleas are a little more tolerant of cultivation than most other proteaceous genera, but much variation exists among the individual species. It is possible to establish some grevilleas on limestone or heavy clay soils. I have had some success germinating grevilIeas by carefully strip­ ping off all the Oll ter seed coats and planting the naked seeds, barely cov­ ered, in sterile vermiculite. This tech­ nique, described for grevilleas by an Aus­ tralian gardener, Mr. ]. S. Howard, in Leucadcndron argenteum, silver tree. 1963, may be worth trying when seed Tree up to 30 ft. high. Leaves 5 to 6 coat dormancy seems to be a problem inches long, silvcry.gray, with ad­ that cannot be readily broken by less pressed silky hairs. Male and female drastic methods. flowers on separate plants, the male flowers in heads and conspicuous, Hakea: More than a hundred species the female heads not showy and hid­ of shrubs and small trees in Australia den by the upper leaves. Fairly com­ and Tasmania. Like the grevilleas, mon in California gardens, less so in hake as seem to be a little more easily Florida. Native of the Cape area of 'grown than most of other proteaceolls South Africa. plants. In South Africa some imported Puo 1'0 DOUGLAS ELl.IOT f species of Ha'kea have escaped from cul­ tivation to become naturalized, and have devdoped into aggressive, noxious andra, like many other Australia plants, weeds in certa1in areas. Hakea laurina, are fire-followers. The seeds do not read­ the most commonly cultivated species, ily sprout unless subjected to heat, and has globular red inflorescences studded after a bush fire may be observed like a pincushion with creamy white sprouting in profusion on the freshly pins. charred earth. Under artifioial condi­ Isopogon: An Australian genus of tions it is usually advisable to subject about 30 species of shrubs. They are such seeds to treatment with boiling commonly called cone bushes or drum­ water to stimulate germination. sticks from the cLll~ious thistle-Eke flower Embothrium: Three species of small heads held stimy at the ends of the trees in western South America and one branches. The inflorescences of the vari­ species in Queensland, Australia. This is ous species are found in shades of white, a small genus of great ornamental value. yellow, pink, red, and purple.

154 AMERICAN HORTICULTURAL SOCIETY Leucadendron: 70 species o[ shrubs one of the most characteristic elemen ts or small trees in South Africa. The flow­ of the unique Cape f-Iora . The natural ering habit of some speoies of L eu­ habitat of the. proteas closely resembles aidendron is not 01 particular note but the chaparral scrub of the dry mountain the genus is of interest in that it is one slopes in our western states. In many of of the few in the family that is dioecious, the proteas the most intense coloration with male and female plants. of th e inflorescences is not in the flowers, L eucadend1'On argenteum is famoHs but in a series of floral bracts below the true flowers. PTotea cyna1'Oides, for ex­ [or its foliage which is densely covered ample, bears huge silvery-pink f-Ior al with silvery hairs, giving it a glistening heads reaching six inches in diameter, metaUic sheen. This tree is subject to a mysterious malady causing a fatal de­ the largest in the genus. As a group cline even in its natural habitat on the these plants comprise a truly stunning group of shrubs. exposed mountainsides of the Cape of Good Hope, and there has been some Stenocarpus: This is one of the less worry that the species may be disappear­ common tropical genera, consisting of ing. Yet, it is grown in California, and 30 species of trees in the forests o[ New near Santa Barbara has become suffi­ Guinea, New Caledonia, and northern ciently naturalized to form self-seeding Australia. One species, Stenocarpus sinu­ groves. atus, is grown in Florida and is a hand­ L eucospermum: 32 species of shrubs some small evergreen tree, very compact almost entirely South African. All pro­ teaceous plants have inflorescences made up of a number of individual flowers more or less densely arranged in a head, on a spike, or along the branchlets. The inflorescences of the L eucospermum are in heads, rather resembling spidery chry­ santhemums. These shrubs are very floriferous when established, and make an intense mass of color in the garden. Macadarnia: A small genus of 14 spe­ cies, but interesting because it is found both in Australia and on Madagascar. Although a number of genera in the family occur in both the Pacific and the South American distributions, very few are shared with Africa. NIacadamia is not especially showy in flower, but one species bears edible nuts that are an item o[ commerce in this co untry. Macadamia integl'ifolia is a large shrub or small tree with curious strap-like leaves edged with sharp-toothed prickles. The nuts are delicious, but the shell is so nearly impenetrable as to make them very difficult to crack. The PHOTO DOUGLA S ELLIOTT plants are grown commercially in Leucospermum reflexum. Erect­ Hawaii. branched shrub up to 10 ft. high, PTOt ea : 90 species of small-to-Iarge almost wholly covered with bluish­ gray down. Flower heads 4 inches shrubs in Afl--ica, most of them concen· long by 2 inches wide, the flowers trated in the Cape Province. This genus crimson. Cultivated in California. has given its name to the family, and is Native of South Africa.

FALL 1969 155 in habit, ami with deeply lobed, oak­ not easily duplicated in the garden. It like, glossy greell foliage. T his tree i, may be that as gardeners we should be "ery showy in Hower, with brilliant red gra teful [or the occasional w,ild thing flowers in heads, arranged somewhat like that cannot easily be reduced to the Lh e spokes of a ca n wheel. Dr. Edwin st:Hus of a g-arden ornament, and that Menninger reports this tree may require reminds us of our limitations and our 15 years or more to flower from seed, own humble status. Things that grow although it is fas t-growing for me. too easily often become weeds. At tIle T elo pea : Three species of large sa me time we should be aware that shrubs in A ustralia and Tasmania. gardens h ave often been the last refuge Call ed \J\Tara tah, and at leas t one of of plants that would otherwise disap­ them, T elopea speciosissim.a must be pear, and that are disappearing every numbered among the finest of the day through destruct,ion of their natural world's flowering shrubs. This plant habitats. In this respect, at least, garden­ bears large globose flower heads of an ers bear a certain stewardship for tht ~ intense red hue. A well grown plant may entire race. carry more than 'JOO such flower heads for anyone who is willing' to take up in a single season. Unfortunately, like the challenge of growing these beautiful most a11istocrats, it does not tame easily, but difficult plants I will list a number and even the Australi ans co nsider it one of seed sources I h ave found rel,iable in of the most difficult to grow of their the pas t. Remember that it is necessary native plants. Telopeas grow in areas to secure a permit from the division of subject to periodic burning over, and the United States Department of Agri­ perhaps as a response to this environ­ culture concerned with plant importa­ ment develop a large woody excresence, tion before ordering plant materials of known as a lignotuber, a t the base of the any k'ind, including seeds, from outside plant which is relative ly fire resistant, the country. The"e permits are free and from which the plant renews itself upon application to the Agricultural after burning. Such an environment is Research Service, Plan t Quarantine Di-

PHOTO E. ivfEl\'IMLF.R teucospermum grandiflorum. Growing in garden of J. Howard Asper, Sr., Escondido, about 30 miles noth of San Diego, California.

156 AMERICAN HORTICULTURAL SOCIETY vision, 209 River Street, Hoboken, New New.lands, Cape Province Jersey. . South Africa It would be worthwhile, before trymg Note: This involves membership in to grow plants of the Protea family, to the society, which is inexpensive, and an become acqua1inted with some of the annual seed distribution program simi­ cra rdenirw litera ture concerning them. A t> 0 lar to that of the American Horticul­ number of books, mostly South African tural Society, except that the seeds are and Australian in origin, are available [rom the Society's botanical garden at from dealers in books on horticulture Kirstenbosch. and natural history, with much valuable King's Park and Botanic Garden informa tion about the Protea family. Perth, vVestern AustraEa The delightful quarterly journal "Aus· Australia tralian Plants" published at 860 H enry Lawson Drive, Picnic Point, New South N indethana Seeds Wales, Australia has over the years pub­ c/ o G. W . Althofer li shed numerous articles containing Box 5 practical advice on the Australian mem­ Dripstone, ew SOllth ' Vales bers of the family. The Botanical Society Australia of South Africa, whose address is listed H oningklip Nurseries below, has published articles in its jour­ c/ oW. ]. and Mrs. E. R. Miclclelmann nal, many of them available as reprints "Barosma" or pamphlets, about growing South Afri­ Barmbeck Avenue can proteas. Reading any of these books, Newlancls, Cape Province articles, or pamphlets will be time well South Africa spent. Peter B. Dow & Company Sources of Seed: 7 Rutene Road The Botanical Society of South Africa Gisborne Kirstenbosch New Zealand

l"H01 Q E. lV1 J.:,1\,I Ml..ER l'rot(>(1 barbigera. G.·owing in ga.·dell of J. l-Iowal'(1 As p«"" S,·. , Escondit10, about 30 miles north of San nit'go, CalifOl·n ia.

FALL 1969 157 Flower Colors and Color Fans

JOHN M. PATEK

The Ame1'ican H OT ticultuTal Society is pleased to p1'esent this aTticle by MT. John M. Patek. He is pTesident of Calm' Data, Inc., was formerly a co lor expeTt with Eastman Kodak Company, and is exceptionally well qualified to discuss this subject. Color is of j)")"imary impoTtance to gaTdeners the wodd over. The opportunity to study authoritative work in this highly technical field is an opp01·tunity to improve our undentanding of color as a basic factor in ornamental horticultw·e. This aTt·icle is based on a paper presented before the American Daffodil Society in A pTil 1969.

Introduction the flower with a suitable Munsell color I am very pleased to be asked to come sample. to Nashville to talk about a subject on My study of flower colors goes back to which almost everyone is his own expert. August 1966 when the Royal Horticul­ Last month a small garden club in tural Society color fan was introduced at Rochester asked me to talk on this same the 17 th In terna tional Horticultural subject. After I hac.! proceeded for haH Congress. The mere process by which an hour, one earnest young lady inter­ the colors were selected was intriguing rupted me to say, "Everyone sees color in itself, because it was bound to inAu­ differently, and why is your idea of color ence the results. any better than anyo ne else's?" I decided To develop the colors of the RHS fan to satisfy her, if I could. This necessi­ a committee met 26 times over a year's tated going back a few years. duration. On the committee were rep­ In 1931 the International Commission resentatives from Kew Gardens, the N a­ on Illumination reached an agreement, tional Dahlia Society, the Royal Nation­ at a mee ting held in London, which al Rose Society, the Royal Color Coun­ es tablished the characteristics of the cil, and the Royal Horticultural Society. standard observer. This standard observ­ The resulting fan was divided into four er was an instrumentally determined nu­ books with a total of 808 colors. The merical definition of color for the aver­ results of this effort might or might not age human eye. Tests h ad shown that be good. I decided to find out. my eyes h ad high se nsitivity to color To test the fan, I used the flowers differences and that my color evalua­ which were then in bloom in my own tions coincided with those of the stand­ ga rc.!en. I attempted matches between ard observer. In other words, I could the colors of the flowers and the colors establish quite accurate Munsell nota­ on three different color charts or fans tions for flowers by vislIal comparison of (Fig. 1) . Matches were graded A, B, C, or none. Results with the ISCC-NBS 4·34 Mount Airy Drive. R ochester. New York 146'17. Member, Board of Directors. The Ameri · (National Bureau of Standards) Cen­ can Horticulrural SOciety. troid Color Chart were almost as good as

158 AMERICAN HORTICULTURAL SOCIETY those obtained with the RHS Color structure of the hemoglobin found in Chart. But the ISCC-NBS chart was nev­ man. With the chlorophyll in the leaves er intended for flower colors and it has of trees there are generally two hydro­ only 235 colors in all. What did this carbon pigments, related in structure show? It showed that a scientifically ar­ and known as carotenes and xan­ mnged series of colO1"5 is faj' more effi­ thophylls, which give the leaves their cient than a set of colors selecteel at mn­ orange and yellow colors in the fall dom or by commiuee action. when the chlorophyll decomposes. These two pigments are included under Chemistry the larger classification of carotenoids, I started out assuming that each spe­ with the basic chemical structure of Vi­ cies would have its own distinctive col­ tamin A. The yellow xanthophylls may ors, but soon found that this was not the be considered as oxidized orange caro­ case. T he same purples, yellows, or­ tenes and are present in most yellow and anges, and reds appeared over and over lemon-yellow flowers, including the tu­ again, irrespective of the species of lip, lily, crocus, and daffodil. flower. There was, in fact, a rather lim­ I have not yet mentioned the most ited number of colors, on the whole, and important group of flower pigments-the these fe ll into specific systematic ar­ f1avonoids. They are limited to the high­ rangements. er order of plants and occur in all flow­ A review of the chemical literature ers. They have a common structure revealed that my observations were based on flavone and differ from one sound. Vegetation, irrespective of species, another by their states of oxidation. In­ owes its green color to a single chemical cluded in this group are the flavones and called chlorophyll. A very small change flavonols which vary from pale cream to in this chemical, involving primarily a deep yellow, depending on the number substitution of an iron atom for a mag­ and orientation of their hydroxyl (OH) nesium atom, produces the red chemical groups. Most white and all yellow flow-

COLOR TESTS

Plant RHS Color Chart ISCg~ c-tro1d NioQ1"II0I1 Color Fan 10.. Chart. GNde ot Notation Notation Gr&de ot Rotatioo Grade ot Match Match lfatoh

Gerani_ 'Orange Glow' 33A C 7.5 R 5/13 B 34 v r 0 C Yellow Viola 1U A - poor not tuted Oranp Pansy Dark none none DOlle

Red R-.roc&l.lia 178A B none U d_p r Br C

Pet1lllia 'Peach Bloe aoa' 58C C 7.5 RP 6/12 B not hated

Pwtlll11a 'Purple Pl_, 74B A none 237 8 r P C

Petlll11a 'Red lfap.c' 50A C 2. 5 R 5/12 C 11 v R B

Petlll11a 'lIuquer&de' 8JA B 5 P 3/9 C 220 v dP A Red-purple Petunia 6U B 7 . 5 RP 3/9 c 256 d_ p p R C

BlIM PlatTCodon 88C C 2. 5 P 4/9 c none

p~.~tlrua ';01'1 7 ~ liP ~/Q ll. ., <1_n II A A B - PeriJlber7 590 7. 5 RP 5/12 25 v p R

Purple Verbena none 2.5 RP 3/8 C 2)8 r P C

F ig. 1. Results of a test of three colOl" charts in the attempted matching of {t owel" colors in on e garden at one tilne.

17 LL 1969 159 Fig. 2. Basic struc­ CI ture of the andlo­ cyanin nlolecule showing where OH the presence of metal complexes at the CI position, and of additional o hydroxyl (OH) Gi"'COs< groups at the ex­ treme right will change the color from red to blue. ers contain these pigments, but strong tant single factor in flower coloration, yellow colorations may also be due to an since all colors prod uced with black are accompanying carotenoid. missing in flowers. The nearest ap­ The most important and strongest proach to black is when chlorophyll pigments of the flavonoid group are the green combines with anthocyanin red. anthocyanins. They produce the colors The very dark colors in flowers are usu­ ranging from orange, red through pink, ally produced by very high concentra­ red, and blue. They differ from the tions of pigment. Pigment concentration yellow f1avonols by having a free electri­ may vary from 0.1% to 15% of the dry cal charge which makes them susceptible weight of a flower. to changes in cell sap acidity and assists There are a few additional causes for their complexing with metals. The an­ color differences which I have not men­ thocyanins differ from one another in tioned. The brown color of P1'imula X the same manner as the flavonols, that polyantha was found to be produced by is, by differences of hydration (Fig. 2). a magenta anthocyanin on a yellow ca­ Blueness increases with the hydration of rotenoid background. The brown iris is the basic compound, but blueness is fur­ similarly a mixture of yellow and violet ther increased by lower cell sap acidity or magenta. Microscopic examination and the presence of metal complexes. showed yellow cells, each capped with a Thus the blue cornflower or bachelor's spot of purple. Some diffusion of purple button and the red rose have the same from the spot into the yellow cell was cyanidin pigment, but under slightly observed under lOO X magnification, different conditions. and the depth of brownness increased Basically, the same anthocyanidin pig_ with the size and number of the violet or ments account for the orange-red to blue purple caps. Colorless flavonoids as co­ colors of all flowers. Orange and scarlet pigments with anthocyanins will pre­ flowers contain the pelargoniolin pig­ sumably affect color. Tannins will pro­ ment obtained from the geranium, crim­ duce gold or brown. Anthocyanins have son and magenta flowers have the cyan­ attached sugar molecules to make them idin of the rose, and lavender and blue water soluble, and increasing the num­ flowers have delphinidin of the del­ ber of such molecules will increase blue­ phinium. ness. Yellow pigments wi th anthocyan­ The flavonols and f1avones supply in blues, which are always slightly red­ creamy white pigmentation and all dish, will increase the appearance of strong whites are slightly yellow. blueness. 't\Thiteness is also produced by the ab­ It perhaps should be mentioned that sence of pigment accentuated by the the coloring matter of flowers should not presence of air in intercellular spaces. be confused with natural dyes such as Although there are near-white pig­ indigo whidl is made from the colorless ments, there are no identified black pig­ sap of yellow f10werillg plants. ments in flowers. This is the most impor- - I have given you this immersion into

160 N

Fig. 3. Munsell color solid showing yellow as a high chroma light color, purple as a high chroma dark color. Projec­ tion of the hue circle is at the base, and ex­ tension of the neutral axis is at the top.

chemistry to show you that our color not ultraviolet or infrared. Green is in problem is related to a very limited the middle of this range and is seen best. number of materials. The colored wine However, it is possible with a spectro­ you drink has the same anthocyanin photometer to determine the exact per­ substances as the red roses you pick for centage of the original light which is the table. Any color card which attempts reflected by an object, and to do this to give complete coverage of all colors wavelength by wavelength across the en­ will go beyond the requirements of tire visible spectrum from violet to blue flower colors, and probably fall far short to green to yellow to orange and to reel. of portraying those specific colors and From these individual readings can be arrangements of colors found in flowers. calculated the exact color one will see. I have introduced you to the basic Every color has three characteristics factors in the specific problem of flower which can be individually determined colors. Now let us discuss color itself. by the spectrophotometric measure­ ments and calculations. These character­ Munsell Color System istics are the lightness or darkness of the When the light from a very hot object color, termed "reflectance," the strength like the sun strikes a colored solid like a or saturation of the color, termed "puri­ flower, some of the light is reflected from ty," and the color itself, termed "domi­ its surface and some is absorbed. If all of nant wavelength." The whole system is the sunlight or daylight is reflected, we known as the CIE Color Coordinate see the object as white. If none is reflect­ System. ed the object looks black. If some of the As stated above, the eye does nut see sun's rays are reflected and some are not, all colors equally well, and so the color the object has a color, depending on differences "seen" by the instrument are which rays are reflected. not exactly as the eye would see them. The eye can detect only a limited That is, the instrument does not divide range of the reflected radiation from the color into the same equal steps as the sun, or in other words, it can only see eye. For this reason, an arrangement of radiation as colors from violet to red but the above instrumentally determined

FALL 1969 161 data was developed to divide color as the eye sees it, and this is known as the Munsell System of Color Notation. This sy tem has world-wide acceptance for both sci­ entific and commercial applications. In the Munsell System the reflectance or light­ ness and darkness is termed " value." The purity, sat uration or in­ tensity of a color is termed "chroma," and the dominant wave­ length or actual color is termed "hue." This whole system is de­ scribed as the "Munsell I I I I Color Solid," because the three mea.suremen ts Fig. 4. Complete Munsell hue circle. Shows in of value, chroma, and detail the circle at the base of Fig. 4. hue can be expressed as three domensions of a solid (Fig. 3). The center axis is a high and the purple side low, since vertical scale divided into 10 numbered yellow is light and purple dark. units from black through shades of gray Since each numbered unit in the to white without chromatic color. This Munsell System can be carried to at least is the value scale. As one moves from the one decimal place, it is possible to de­ center axis out to the outer surface of scribe, with numbers representing light­ the solid, color is introduced and be­ ness, saturation, and hue, anyone of the comes more intense until maximum in­ two million colors which the eye can tensity or maximum chroma is reached distinguish. As an example, a daffodil in at the outer surface. This is measured my garden has a cup with Munsell nota­ in units up to 18 in number. The hue tion 5.0Y 8.5/13 and petals with nota­ or color changes as one goes around the tion 5.0Y 9.2/2. solid, or looking down on it from above Unless you are accustomed to using one sees the full hue circle (Fig. 4) . the Munsell notations, they will not The Munsell circle of hues has 10 bring to your mind a particular color. hues, each divided into 10 units. It is However, the National Bureau of Stand­ similar to the color harmony circle with ards has made available through the which your flower arrangers are familiar, Government Printing Office, in their except that blue-green rather than green Circular 553 "The ISCC-NBS Method is opposite red. The complementary col­ of Designating Colors and a Dictionary ors of the Munsell color circle are those of Color Names," a system for giving a of light which produce white when mix­ color name for each Munsell notation. ed, while those of the color harmony In addition, there are published Mun­ circle are based on pigment mixtures sell notations for both the Wilson and which produce gray or black when mix­ Ridgeway color charts. ed. The Munsell color circle in relation Occasionally it is desirable to coin to the vertical neutral axis is tilted from color names. The use of color names the horizontal so that the yellow side is which attract sales is common in the

162 AMERICAN HORTICULTURAL SOCIETY pawt industry but added Munsell nota­ there is general! y a tendency toward tions identify the colors. grayness. This means that colors which were intense pure colors before mixing Color Samples, Cards, and Fans produce a new color which is grayed A color numbering system alone will down or lower in saturation. Thus color not meet your needs. You must have card manufacturing processes which mix physical color samples, such as a color and then knife or flow the coloring card for color identification. If you wish material onto the color card are handi­ to determine the Munsell notation of capped in obtaining the needed color the color of a flower, you can lise a saturation [or flower color identification. spectrophotometer, as I sometimes did, You will recall that the anthocyanin but this is a $15,000. instrument and is coloring in flowers produces a whole not very common. Your other alterna­ range of colors by changes in compound tive is to use a color sample with a structure, and only occasionally by ad­ Munsell notation which will match ap­ mixtures. The Munsell Color Company proximately the color of the flower. has largely overcome the color mixture An exact match between flower color problem by printing many coatings of and sample color will probably not be transparent ink one over the other to found. What is required is a series o( obtain the desired color without pig­ colors with Munsell data evenly spaced ment mixing. as the eye sees them so that yo u can estimate where, between two color sam­ Flower Colors ples, your unknown color falls. Then The examination of a flower petal yo u can interpolate or extrapolate the surface under 100 X magnification re­ Munsell notation for your flower color. veals a layer of translucent cells which If you have a table of agreed-upon color have the appearance of clear colored names for specific Munsell notations, gems. Where the flower shows good sub­ you can correctly name the color of yo ur stance and strong color saturation, these flower. cells may be packed so tightly together Series of Colors are presented in the that they assume the hexagonal shape form of color charts or color fans. The characteristic of the ce ll ~ of a hon­ making of a suitable color fan for horti­ eycomb. The intensity of color produced cultural purposes is not a simple matter. by some flower surfaces of this type Besides the problems of design, the exceeds anything man can produce with physical materials which go into a fan dyes or pigments. are a challenge. The color samples must The extremely high color saturation be water-resistant and fade-resistant and of many flowers may be attributed to the must include colors of maximum color presence of a single pure dominant pig­ sa turation or chroma. It so happens that ment, the light-refracting and light­ the strongest, most brilliant, and greatest filtering nature of the surface cells, and range of coloring materials are among the intensification of color produced by those which fade most readily, so the internal reflectances. Do you remember choice must be made as to whether one the powder room you painted a pale sacrifices color for fading or vice versa. pink which turned out to be an intense Unfortunately, fade resistance has some­ pink? times been sacr.jficed for the sake of The unavailability of non-fading col­ color. or samples with sufficiently high color Since the number of good non-fading saturation was the major problem in the pigments is limited, it becomes necessary development of the new color fan for to mix pigments in order to obtain the The American Horticultural Society. exact color desired. As you well know, The Munsell Color Company made up the mixing of pigments of three primary several special color fans with colors of colors will give gray. When two pig­ high saturation arranged in steps to ments of differing colors are mixed, how numerical differences in hue, val-

FALL 1969 163 ue, and chroma that permitted extrapo­ wavelength across the entire visible spec­ lation beyond what was available. Over trum. When the eye sees two colors at 200 flowers were studied for color evalu­ once, only one color is visibly sensed; ation with these special fans. Sources of that is, if the eye sees red and blue at the the flowers were Rochester, New York same time, purple is the color sensed. city greenhouses, rose gardens and parks, On the other hand, the spectrophotome· the flower trials of the .Joseph Harris ter curve shows both the red and the Company, small growers' fields, and pri­ blue, and only by mathematical treat­ vate gardens. Tests covered the entire ment of this information is the purple growing season. determined (Fig. 5) . Where flower colors were not covered Colors which are a combination of by Munsell color samples, the flowers two colors are called metameric colors. themselves often were mounted in card· It is these colors which change with the board holders and read in a General quality of the viewing light. Daylight is Electric Recording Spectrophotometer. much bluer than incandescent light. A This instrument records on a chart a purple petunia will look bluer in day­ curve which shows the relative amount light and redder in incandescent light, of light reflected from the flower at each because of the metameric quality of the

100

90 1 Blue Ir1l 2 Bluo I'ano7 3 IU.ue Cioararl& 4 *ccta CiDlU'&rl& Bor- 5 r_uov hAq r 5 I

70

Fig. 5. Spectro­ 60 photometric curves showing the similar­ .... ity of color irrespec­ ~. 50 tive of species, the high red content of § the blues, their 40 metameric nature, and the slight shift to turn blue into magenta.

164 AMERICAN HORTICULTURAL SOCIETY anthocyanin coloring m aterial. The produce a dark yellow, and 110 true dark spectrophotometric curves of magenta yellow or olive was fo und. and purple cinerarias are similar except Some an thocya nin pigments appear for the relative amounts of blue and red almost black. Spectrophotometric curves reflected light. They show the metamer­ of an almost black purple iris, an almost ic nature of the anthocyanin pigment black red tulip and a dark brown pansy whose tendency to reflect blue will re­ were very similar. spond to blue in the illuminant, and They all showed red reflectance with a whose red will respond to red in the little added blue for the iris and a little illuminant. It can be seen from the yellow for the pansy. These dark colors spectrophotometric curves that the blue are difficult to reproduce, because of color of a flower would be expected to their high color saturations. contain some red. All of the flowers showed considerable Flower Color Distribution red, and green foliage showed some red Let us complete our analys is by going when tested in the spectrophotometer. around the Munsell color circle starting The red increased toward the infrared with red. The reds in flowers will be end of the visible spectrum, and it is very strong, highly saturat·e d colors, start­ apparent that plants reflect considerable ing from dark reds and going toward infrared energy or heat. It is in this part reds of extremely high chroma and of the visible spectrum that human abil­ medium lightness. As they become ity to see becomes poor, which explains lighter they rapidly lose their color satu­ why many photographs show flowers to ration and become pinks. appear pinker, redder, or more purple The yellow-reds or oranges start with than they appear to the eye. very dark colors of extremely high color I mentioned that the blue and red saturation which are brown that cannot flowers obtained their colors from the be reproduced in any medium, except as same pigments under slightly different in the brown primros·e and iris where conditions. This can be shown by expos­ brown is a blend of yellow and purple ing certain red flowers to ammonia va­ and therefore dull. They follow on a por, or blue flowers to acid fumes to line to a point about two-thirds up the reverse the colors. Under these circum­ black-to-white gray scale where they stances one would not expect to find a show extremely high chroma. Then, as true blue flower. I sought out all avail­ they become lighter, the color saturation able flowers known to be blue, and nev­ drops off rapidly and produces pale sal­ er found one which would be rated blue mon pinks. The color distribution pat­ by the Munsell Color System. tern may be considered to fall halfway I have never found blue-green flowers. between red and yellow. However, berries of the porcelain A m­ Yellow in flowers is unique in that it pelopsis proved interesting because they has usually almost no variation in ligh t­ did show blue-green blending with yel­ ness and darkness. Yellows fall on a low-green and purple-blue. Blue-green is straight line that shows only a change in very unusual. "Blue" foliage is usually sa turation or chroma from a very weak gray with a little green or yellow-green. yellow to a very strong one, or a simple decrease in the amount of pigment. One would expect all green foliage to The green-yellows or yellow-greens be somewhat greyed or low in chroma vary from fairly dark colors of low to because of the red coloration shown by medium color saturation to very light the spectrophotometer and fall coloring. low saturation yellowish whites. Most This proves to be the case. R ed and foliage is yellowish green rather than green produce gray. tnle green, and true greens are usually Since there apparently is no identified fairly light and of low color saturation true black in nature's stock of coloring or chroma. They occur as a tint in gray materials for flow ers, th ere is nothing to foliage, commonly identified as blue foli-

FALL 1969 165 age. The blue-greens are so uncommon Red-purple or magenta colors extend that they can be ignored, and blue, ac­ from colors high in chroma and not very cording to the Munsell Color System, dark to light colors low in chroma, or has not been found in flowers or foliage . pink. This again shows a simple contino Purple-blue follows a straight line uous decrease in pigmentation. from an amazingly highly saturated high chroma, very dark color to a light laven­ The AHS Color Fan der of low chroma. This represents a Last spring the Munsell company straight line diminution of the purple. gave me for trial use six sets of a partial­ blue pigment. ly completed experimental color fan Purple has a more scattered distribu­ made by a new process designed to pro­ tion than purple-blue. It shows dark duce colors of high saturation. They colors from low to high color saturation, were distributed to seven of the largest colors of medium lightness and medium arboretums in America for use and com­ saturation, and those which follow a line ment. The general response was that toward light colors of low saturation, or this was the first really useful color fan pale lavender. for flowers.

Excerpt from Peter J. Van Melle

On Landscaping Service (1951) There are available to you mainly two types of service. One is that of the professional Landscape Architect; the other, that of the commercial nursery establishment, the so-called Landscape Nursery. How do these two types of service compare? I should say that in the best instances on either side, the difference between the two services is the least prominent. If you can find a landscape architect with a first-rate knowledge of plants and planting you will get a fine type of service; as you will, also, if you go to a nursery where good design talent is employed. You can hardly go wrong in either case. But in most instances the two factors, design and plantsman­ ship, are not so ideally combined. You will find that the average landscape architect majors in design, and the nursery establish­ ment in the practical varieties. Sometimes the landscape architect is more or less deficient in the practicalities, and the nursery outfit in design. Neither has a monopoly of good landscape work. Since you are likely to be up against the average of the two types of service, I think that in many instances it may be best to employ both. You may do well to engage a professional landscape architect to design your project. He will probably do a better job of it than a nurseryman. But I think that you may well terminate the professional service after you have obtained a plan and specifica­ tions. Then you might take these to whichever appeared to be a reliable, local nursery, and have the plans translated into terms of practical, local plantsmanship, and have the nursery furnish you, directly, an estimate on the cost of the job. I think that in such a way you may well get the best out of both types of service.

166 AMERICAN HORTICULTURAL SOCIETY My Friends the Penstemons

GLENN VIEHMEYER

Of all the wild flower tribes of North humming birds that pollinate it, or America none can compete in beauty watch the scented P. palmeri call the with those of the genus Penstemon. This bees that transfer pollen from flower to genus of plants ranges from the Atlantic flower. to the Pacific; from mountain meaiow You can visit highland or lowland, to desert; and through the sub-humid mountain or desert or plain to meet and and humid lands of Eastern North fall in love with the penstemon. You can America. Authorities differ as to the collect seed and grow seedlings in your number of species, subspecies and geo­ own garden and find wild species, the graphical races but it seems the concen­ most cantankerous, the most downright sus that these are numbered in the hun­ exasperating plants you ever tried to dreds. grow. You can watch them die of dis­ In form, these plants are just as varia­ eases they never encounter in their wild ble as are the habitats in which they home. These plants are specialists, grow. They are upright, prostrate, vine­ adapted through millions of years to the like, or shrubby. In size they range from habitats in which they are found. They the %-inch height of Penstemon caespito­ are plants for very special environments, sus subsp. desertipicti to P. havardii and P. palmeri which tower to six or more feet. Flowers range .from a quarter-inch wide ones in the "mint cluster" penstemons to the two-inch wide bells of the hardy Penstemon cobaea X P. triflorus hybrids and the new, tender, tetraploid forms being created in Cali­ fornia. Penstemons are the most beautiful, the most variable and the most spectacu­ lar of native plants. In a "good" pen­ stemon year you can visit the hills north of Wray, Colorado and see a thousand hills misted pink with the flowers of P. ambiguus. You can drive across the gravel fans of northern Nebraska and see acre after acre of P. grandiflor·us. You can drive the foothills of the Front Range of the Rockies and see the fa llen bits of western sky that are P. glaber. Prowl the southwest deserts and high plateaus of Arizona, New Mexico and j"'HOIO U ;\ J\J:RS1IY OF l'-EBkA,:,J\.A Utah, and see the scarlet bugler, P. Penstemon Henry hyhrid. Seed grown, eatonii sending its bugle call to the true breeding hybrids of P. cobaea and P. triflorus, introduced by Uni­ Route 4, North Platte, Nebraska 69101. versity of Nebraska.

FALL 1969 167 unhappy when moved to the decidedly better in the garden than are their wild different type we call a garden. These progenitors. The breeders have taken plants are killed by the kindness of the the wild species apart and put them gardener who overwaters and overfertil­ together again in forms unknown in izes them. They just are not garden nature. Colors include those not found plants. in wild pents. Characters for repeat Many persons do grow the species and bloom are appearing in many lines. Ease anyone can grow them if he is wi lling to of culture and longevity are objectives. simulate the habitat in which they are Today we have the materials and the found in nature. You can grow them if know-how to make these plants impor­ yo u protect them from the diseases they tant in the garden. Most of the credit for seldom encounter in the wild. Most of these advances belongs to the dedicated yo u will not or can not do this. As a people of the American Penstemon Soci­ group, penstemon species are not for the ety. These people have collected and gardener who wants maximum effect grown the wild species and have blended with minimum effort. As a rule, species them into hybrids that are becoming native to your own part of the country good garden subjects. may perform well in your garden but those from far places may be short-lived, Breakthrough blooming once and then dying. A breakthrough in taming the pen­ This probably sounds discouraging to stemon of the north occurred when a the beginner who would grow pen­ Montana nurseryman named Murray stemon, but the situation is not that bad. discovered a natural hybrid of P. bar­ Years of work by amateur and profes­ batus growing near his nursery on the sional breeders have produced pen­ shores of Flathead Lake, Montana. This stemon varieties and strains that are far hybrid is presumed to be a cross of P. bal'batus and an unidentified Montana native. Murray increased the hybrid in his nursery and Anna Johnson of Butte, Montana obtained a plant from him. Seed from this was sent to the Rock Garden Society and distributed by them. This wild hybrid proved to be the most important northern penstemon col­ lected since the APS started bringing wild species into cultivation. It was im­ portant because it was compatible with a wide range of species and has been used to produce fertile or partially fertile hybrids within them. Because of this ability the plant, which had been dubbed "Flathead Lake", was deemed worthy of a scientific name. R alph W. Bennett and the author described the plant in an article in the Bulletin of the American Penstemon Society, Vol. 20, 1961, pp. 15-16 and named it Pen­ stemon X johnsoniae 'Bennett'. The true P. X johnsoniae perhaps no longer exists except as herbarium speci­ mens. Its descendants, known as the PHOTO U NIVERS IT Y OF NEBRASKA "Flathead Lake hybrids", are plants of Penstemon barbatus considerable garden value.

168 AMERICAN 'HORTICULTURAL SOCIETY The North Platte Penstemon strain is short lived and for that reason Breeding Project Begins is not popular with nurserymen. Clonal material has been selected from Flat­ The story now must become a person­ head Lake hybrids, which are better alone. As far back as 1928 I became nursery plants and are being grown by interested in attempting to hybridize nurseries across the United States and penstemon, and collected several kinds Canada. One Flathead hybrid strain, in my garden at Stapleton, Nebraska. 'Prairie Jewels', has been grown and sold During the blooming season I made by a major mail order nursery company several hundred interspecific crosses and for several years. obtained a single seed which failed to germinate. This cooled my interest in At the North Platte Experiment Sta­ penstemon breeding. tion, the author has named and released three clones to growers. These are 'Prai­ In 1951, Mrs. Edgar Irving of Omaha, rie Dusk', a deep violet blue; 'Prairie Nebraska sent me a package which con­ Dawn', a light pink; and 'Prairie Fire', a tained seed of a dozen species of pen­ stemon. Among them was a packet of scarlet red. More recently, my successor, seed of the Flathead Lake hybrid. Dr. Roger Uhlinger, has released two These I received with no great enthusi­ additional Viehmeyer hybrids, 'Mesa', a asm but I planted them. Perhaps it is light blue upright, disease resistant just as well that some people ar.e slow to clone, and 'Arroyo', a red with good learn, for in spite of the 1928 fiasco, I disease tolerance. made several hundred interspecific cross­ es which were, with the exception of those made with Flathead Lake hybrid as one parent, unsuccessful. When harvest was over I had three packets of seed with Flathead Lake hy­ brid as a female parent and Penstemon strictus, P. glaber and a pink form of P. alpinus as male parents. These three were the beginning of a penstemon breed'ing program that turned a group of wild species into rather promising garden material. . At the time of the first successful cross­ es I was employed as horticulturist at the North Platte Experiment Station. In that capacity I was able to expand pen­ stemon breeding and grow thousands of seedlings. This work continued until my retirement in 1967. Recently it has been reactivated by Dr. Roger Uhlinger who has succeeded me at that Station. Over three decades of breeding and selection have produced seed grown strains alld vege ta ti vely propagated clones of penstemon. Among the seed­ grown strains are the Fate-Seeba hy­ brids of a controlled cross of P. grandi­ floms X P. murrayanus combined with a P. grandiflorus cross with an uniden­ tified species belonging to s·ection Pel­ Penstemon 'Prairie Dusk'. Introduced tanthera. Unfortunately the Fate-Seeba by University of Nebraska.

FALL 1969 169 The major value of these named culti­ hybrids. Penstemon barbatus and P. la­ vars is the high level of disease toler­ bmsus from Section Elmigera and P. ance. In addition to disease tolerance, a. lpinus, P. gla.ber and P. strictus of all five cultivars repeat bloom during Section Habmanthus have contributed summer and fall if not allowed to the bulk of the germ plasm. P. albidus of produce seed. All five are compatible Section A umtor and P. secundifiorus of with a wide range of species and are Section Anuliarius have made a small proving effective in intercrosses and out­ contribution, while the Mexican species crosses. The range of their compatibili­ are just beginning to enter the picture. ties has not been fully explored but there Combining only a dozen or so of the is some evidence that they can make it hundreds of species, subspecies and geo­ possible to bring species of the sections graphical races has brought us a long AnuliaTius and Peltanthera into the way. But this is only a start. The reser· present ElimigeTa and Habroanthus voir represented by the lovely reds, blues gene pools. and pinks of the brilliant PeltantheTO, It is interesting that as additional the sky blues of P. nitidus and august i­ species are added to the gene pool, a few folius and others of the Anuliarius individuals with increased disease should be combined with the Fate-Seeba tolerance are appearing. Thus, species hybrids to create garden varieties. which are themselves susceptible to dis­ The elegant little P. secundifiorus ease seem able to contribute tolerance to with its rosy lavender trumpets and the these complex hybrids. The reason for brilliant red-pink P. utahensis could add this is unclear, but the response is there. excellent flowers and glaucous foliage to Perhaps the hybrids concentrate many the low border. bits of disease tolerance in these resistant The little ETicopsis section consisting individuals; we do not know; we report of P. laricifolius, P. liniaroides, and P. the phenomenon for what it is worth. caespitosus subsp. deseTtipicti might be Whatever the mechanisms are, it has combined with the alpine Dasanthera to been possible to take a group of plants form new kinds of ground cover and poorly adapted to garden use-a group shrubby forms for the rock garlien. of specialists which a million years of The Mexican species of section Fasci­ evolutionary pressure has fitted to spe­ cularis which have contributed to such cific and narrow ecological niches-and cultivars as 'Fire King', 'Garnet', 'Ruby change them to new forms that have the King' and 'Firebird' may contribute ability to thrive under conditions that much to northern penstemons. Indeed, killed their ancestors. the Mexican P. lwnthii is a grandparent of the cultivar 'Prairie Dawn' mentioned Looking Ahead above. The years since a little band of The large flowered hybrids produced amateurs formed the American Pen­ by the west coast seedsmen might be stemon Society have been a time of trial combined with the P. cobaea X P. trifio­ and error. We have a beginning in un­ rus hybrids to outshine the Canterbury derstanding the genus Penstemon. We bell as a garden plant. know how to bypass barriers of cross Much of this business of looking into incompatibility imposed by reproductive the crystal ball and forecasting future isolating mechanisms by using interme­ developments in penstemon is specula­ diary parents. 'J\Te have created a series tion, but speculation based upon years of parents that can be expected to fur­ of working with penstemon. Founda­ ther breach the walls of incompatibility. tions have been laid and new and differ­ We have created complex gene pools ent combinations are now possible. that yield new and better garden forms. Greater disease tolerance can be expect­ This is nothing compared to what might ed, and the character for repeat bloom and will be done as the years pass. will be increased. All this will lead to Two sections of the genus have made better penstemon and greater interest in the most contributions to the existing these new and little known hybrids.

170 AMERICAN HORTICULTURAL SOCIETY One of the biggest needs and one of dragon pollen and produced normal the greatest possibilities for this job of capsules that contained aborted seed creating new penstemons for the Ameri­ that had reached one-fourth the size of can garden is still the amateur who takes normal penstemon seed. Does this mean the time and makes the effort to select that we may cross generic lines to pro­ and breed better kinds for gardens. duce a blue, hardy snapdragon? Can we This business of creating new plants is turn to embryo culture to produce new a fascinating one. Somehow I can't for­ and entirely different plants? get that in a few spare moments I pol­ We have the know-how. Will we use linated a desert penstemon with snap- it?

AMERICAN PENSTEMON SOCIETY Those interested in penstemon Mrs. Robert McQueen, 5501 Wede­ should join the American Penstemon kind Road, Sparks, Nevada 89503. Society. Send $2.00 dues to Mr. Earl You can obtain a free copy of the Holl, P.O. Box 40134, Indianapolis, Indiana 46240. Membership allows bulletin "Penstemon In Your Garden" you to obtain seed of species through by writing the University of Nebras­ the APS Seed Exchange, directed by ka, North Platte, Nebraska 69101.

Excerpt from Peter J. Van Melle

On Foundation Plantings (1951) Solid foundation plantings of (large growing conifers) have gone out of style. The modern house has not the high foundation of its predecessor, and needs no continuous screen of this kind. If you like a band of green along the base, by way of a "line beneath a drawing," you may provide it easily with a mere ribbon of Pachysandra-not necessarily immediately against the house. With or without it, you will probably want a few evergreen things by way of an extension of, or introduction to the architecture of the house. These should be of sufficiently impressive size to be immediately effective in the overall picture. Have no more of them than is strictly necessary for a good picture. If two or three will do, don't plant five or six. No need of a low plant beneath each window, or of a tall one between each two. Do the job with a few well chosen, well placed plants-mainly at the house ends and by the doorway.

FALL 1969 171 Laurel Fig­ An Exceptional Shade Tree

JOHN M. HALLER

"Laurel de la India", Ciudad Victoria, Tamaulipas, Mexico. (See Back Cover for another view.)

"What are those large trees in the "Laurel de la India." This euphonious public square?" asks the tourist as he designation, admittedly more agreeable drives into his first Mexican town. "So than Ficus nitida, is, however, a misno­ huge, so green, so dense!" mer, for the tree is not a laurel nor Nine times out of ten the tree referred anything related to a laurel (although it to is Ficus nitida*, called by the Mexicans may well be an importation from In­ dia) . As examination of its fruits at once indicates, it is a kind of fig and hence a Calle 26, No. 526 lVI endez y Ocam po, C. Vic· toria, Tamaulipas, Mexico. member of the versatile and ubiquitous • The correct botanical name is Ficus micro· mulberry family. Widely planted for carpa var. nitida. (Ed.) shade and ornamental purposes through-

172 AMERICAN HORTICULTURAL SOCIETY out Mexico, from Guatemala to the proportion to their height and trunk Texas border, the "laurel" is one tree diameter. From big branch and little that every traveler to that country is cer­ branch (itself a twig but yesterday), tain to have seen. from primary limb and secondary limb, In well-watered situations this Ficus the twigs shoot out radially, like the grows to be one of the largest of all spokes of a bicycle wheel. Moreo:ver, shade trees. Well-watered or not, it is at new twig growth is not confined to the all times and in all circumstances a outer third of branches, as it is on our front-runner candidate for the title of temperate-zone trees, but occurs all the world's champion shade tree. Even along the length of the massive limbs, when surrounded by impervious deserts from the tree's very center outward to its of asphalt and concrete, it prospers; farthest extremity, by means of which even when battered by passing cars and arrangement an unbroken block of trucks; even when enclosed in unyield­ shade is produced. Only toward the in­ ing iron gratings; even when wrapped in terior where competition for light is chains. Young or old, watered or un­ keenest is the radial pattern modified; watered, in good soil or bad, it bestows here the twigs are absent from the upper the miracle of its shade impartially on side of the limbs, paradoxically and anti­ all who seek refuge under it. Vigorous, geotropically growing downward from evergreen, tolerant of urban conditions, the underside, like hanging vines. incredibly dense, it is one of the very The trunk crotches low, many times at best species for planting in a country a point four or five feet from the where shade is as essential as food or ground, dividing into two, three, four or clothing. more main limbs, four being the most So numerous are the leaves and so usual number. Such a four-pronged thickly and evenly distributed the leaf­ crotch, instead of the commoner two­ bearing twigs that the shade produced is pronged crotch characteristic of, say, the almost solid; few are the rays of light oak or the elm, exactly doubles the total that can struggle down through that twig-bearing surface and helps explain leafy, barrier. When the trees are planted the denseness of the shade. in groups or rows, as is often done, the The large Ficus in Ciudad Victoria effect is to transform what was a hot, measures 5 feet through near the bottom dry, inSl:lpportable public street into a and 7Y2 feet through at the point of forested canyon. Small wonder that the crotching. Each of the fO ,lr main limbs tree is a favorite for plazas and market­ measures 2 feet through. Height approx­ places; what other would do as well? In imates 45 feet, spread 60 feet. Planted Ciudad Victoria, Tamaulipas, the three between sidewalk and street, the tree chief plazas are all shaded by the provides total shade for both at a11 hours "laurel"; one exceptionally fine speci­ of the day; indeed, its branches extend men in the Plaza de Armas is regularly entirely across the street and rub against watered by the fire department as a the store fronts on the other side. matter of civic pride. Almost every town In Xicotencatl, Tamaulipas, I took and city in Mexico has the Ficus planted the following measurements of an even in its plazas or along its avenues, and the larger tree: trunk diameter, 7 feet; particular way they are disposed remains height, 60 feet; spread of branches, 120 long in the memory and serves to give feet; circumference of branch spread, each place its distinctive personality. In measured at high noon by pacing its Leon, Guanajuato, and other cities of circle of shade, 410 feet. In the solid the same state, the trees are commonly shade of this huge specimen the farm trimmed into the shape of bells, animals seek shelter from the sun, in its truncated cones, bowers, and even ani­ ample crotches ducks retire from the mal forms, the plant's density and rapid­ world to lay their eggs, and among its ity of growth making it an ideal subject topmost boughs 30 or 40 bird nests hang for topiary work. secure, almost com pletely invisible from Few other trees have so many twigs in below. The tree crotches about 7 feet

FALL 1969 17 3 above the ground, sending its massive, one leaf in ten is thus affected, but with 2-foot limbs straight outward for 10 or no perceptible effect on the tree and no 12 feet before curving upward. Aerial diminution of its shade. roots, characteristic of many of the tropi­ Bark is light gray, smooth, and often cal figs, are found on it in all stages of covered with a multitude of well-healed development: some just budding from scars. Twigs are slender; when cut or the limbs; others swaying in the air in broken they exude the milky juice char­ their descent downward; others doubled acteristic of figs and mulberries. back onto the trunk and grafted to it. Leaves are elli ptical, 2 Y2 inches long, Fruits are tiny, sweet-smelling figs, too 114 -1 Y2 inches wide. The base is wedge­ inconspicuous to be recognized as such shaped, the tip acute (but rounded, not by the people but eaten with gusto by pointed, at its very extremity) . Margins birds, particularly by the Mexican crows are entire, venation is pinnate, obscured (hurracas) , which frequent the trees in by the darkness and thickness of the large numbers. blade. Both surfaces are smooth; in color The wood is lightweight, easily de­ and texture the leaves much resemble cayed, and of no known commercial those of ligustrum. The petiole is 14 -Y2 value. But this of course was not to be inch long, thick and stout, and grooved expected. Of a tree which gives such along the top side. Leaves are attacked magnificant shade and gives it so un­ by the oyster scale and more seriously by stintedly at all seasons of the year and a sucking insect which feeds on the for so little recompense in the way of upper surface and causes the blade to care, what right do we have to ask for curl up and wither. Sometimes about more?

Excerpts from Peter J. Van Melle On the Name, Viburnum (1947) If there were a good English name for these shrubs, one would like to use it. "Snowballs" won't do. It's an old name for the medieval "Guelder Rose" (Viburnum opulus 'Roseum') and, by courtesy, for other snowball-flowered kinds of later vintage. But most of them just aren't snowballs, nor Hobble-bushes or Way-faring-trees, like V. alnifolium and V. lantana, with their reclining 'and rooting branches to trip the wayfarer. The Latin name is derived from a mention of a "viburnum"-a lowly bush of some sort-in one of Virgil's Pastoral Poems, which has been supposed to represent V. lantana. Can anyone think up a good English name for the genus?

On Selecting Varieties of Shrubs (1950) Let us not, in our selection of shrubs, be swayed entirely by the single, obvious attraction of floral effect, but hold out, instead, for something more than it. Floral effect, important as it is, is only one of a number of good qualities we should look for in the shrubs selected to fill the limited space at our disposal. Other good qualities are, for instance, pleasing foliage throughout the summer, autumn color, pretty fruit, and winter appearance. Combinations of these values, with or without a good display of flower, will stretch out interest in, and enjoyment of our shrubs over a much greater part of the year than will a mere display of seasonal flowers.

174 AMERICAN HORTICULTURAL SOCIETY Advances in Horticulture

Recent Developments in Producing poor phy~cal conditions or the presence More Crops on Straw of soil-borne pests and diseases. P. G. ALLEN* Straw bales, or more frequently 6 to (From The Grower, Vol. 68, No. 19, 10 inch thick slabs cut from a bale p. 841·843, NovembeT 4, 1967) (termed "wads"), are laid on strips of polythene plastic which are slightly Overseas visitors to England's vegeta­ wider than the bales. The straw is then ble producing glass house areas are often w'etted thoroughly and a complete fertil­ intrigued and sometimes startled at izer added and wa.tered in. A small seeing tomato plants growing on what "bed" is built on top of the straw to take appear to be bales of straw. Closer in­ the roots of the tomatoes or other plants. spection reveals that this is indeed the Stenilized soil, peat and spent mushroom case. compost, or peat and sand have proved Producing crops on straw is attracting satisfactory. The s.traw ferments, produc­ attention from many parts of Europe ing some bottom heat and carbon diox­ and from areas as far away as Canada, ide beneficial to rapid growth, early Israel, and .-\frica. The technique of flowering, and fruiting. Since the straw growing vegetables and flowers on straw does not supply nutrients until it decom­ bales allows the production of a full poses, regular light applications of fertil­ crop where s:::>i l conditions would other­ izer are necessary to keep the plants wise make this impossible because of growing well. "\Then the roots are " Director, Lee Valley Experimental Horti· through the straw, growers turn up the cultural Station, England. edges of the polythene, holding them in

Three systems of growing tomatoes in England: on half·bales of straw; in 8· in.deep plastic trays; in a capillary.fed wooden trough.

F ALL 1969 175 place with a httle soil, and thus making weeks. Because the disease reaction may a trough I to 2 inches deep. This serves not appear in the flowers until 2, 3, or 4 as a water reservoir and lessens the need weeks after the flower opens, the disease for frequent watering. symptoms have often been mistaken for Cucumbers, chrysanthemums, stocks, symptoms of senescence that would occur and snapdragons, in addition to toma­ in a disease-free plant. toes, grow well on straw. The photo The infectious nature of this disease shows three systems 'Of growing tomatoes and transmission of the dise~se agent to -on straw wads, in plastic trays 8 inches healthy orchid plants by mechanical .m­ deep, and in a wooden .trough, capillary oculation on a contaminated knife blade fed. has been reported by Thornberry and So if you are unhappy writh your gar­ Phillippe (6). In addition to reporting den soil and want to try something dif­ transmission of the agent, these authors ferent, get a bale of straw, slice it into stated that Cymbidium mosaic virus "wads" and try the English system of (CyMV) and the orchid strain of tobac­ "soil-less culture." Remember, though, co mosaic virus (TMV-O) were both you will need to provide some support consistently isolated from plants for the plants. showing flower necrosis. A causal rela­ tionship between these two viruses and Flower Necrosis in Cattleya Orchids Cattleya flower necrosis was recently re­ ported (7). These authors concluded ROGER LAWSON* that inoculations with pllre cultures of (Adapted f1'Om a manuscTipt to be pub­ lished in the AmeTican Orchid Society CyMV or TMV-O alone did not produce Bulletin) flower necrosis in healthy plants. Corbett (2) reported that the flower necrosis Have you noticed a Cattleya orchid symptoms described by Thornberry were flower producing brown streaks and rarely observed in Florida although spots when it should be still in its prime? TMV-O and CyMV were present in Or did that newly purchased Cattleya many genera, species, and hybrids. corsage suddenly become" old"? Pej'haps This report presents evidence that this was the expression of a virus disease Cymbidium mosaic virus alone can pro­ and not just senescence. Dr. Lawson duce necrotic flowers in Cattleya or­ presents evidence in this report that chids. Although TMV-O can be found Cattleya floweT lUC1'osis can be caused by in Cattleya plants that produce necrotic a single vi1'US that is carried by orchids flowers, the presence of this virus is of the Cymbidium genus. This finding is incidental and has no causal relation­ of great significance in view of current ship to the disease. emphasis on rapid propagation of ViTUS­ free plants by mel'istemming. Materials and. Methods A plant of Cattleya 'Angel Island' was Introduction used as a source of CyMV in all experi­ Cattleya orchids are affected by a path­ ments. Lead samples from this plant ogenic organism that produces brown were tested on Chenopodium amaranti­ spots and streaks in the flowers. This color, Nicotiana tabacum 'Xanthi',-.and disease is of particular concern since Gomphrena globosa for the presenc€ of leaves of infected plants often show no TMV-O. Assays were made using stand­ distinct symptoms and flowers appear anI mechanical inoculation procedures normal when they first open. Necrotic as well as the liquid nitro

176 AMERICAN HORTICULTURAL SOCIETY CyMV was extracted from the source inoculated with a pure culture of the plant by grinding a 50 g leaf sample in virus. In order to determine whether [our volumes of 0.1 M phosphate buffer TMV-O could be complet.ely separated at pH 7.5. The ground tiss ue was from CyMV in our gradient system, a sq ueezed through cheesecloth and the portion of the purified TMV-O sample solution centrifuged at avo 5900 g for 15 was mixed with the CyMV [rom 'Angel mi n 1I tes to remove the large cellular Island' and the mixture was separated components. The resulting supernatant by the fractionation method described. fluid was centrifuged at avo 69,600 g for Assay of the gradient fractions [rom the 90 minutes to concentrate the virus. The CyMV and the TMV-O mixture of 'Xan­ virus was suspended from the centri­ thi' tobacco and ChenojJoeliurn showed fuged concentrate and further purified that a low level of TMV-O co ntam ina­ by centrifugation in sucrose density gra­ tion could be present in fraction C. No dient columns. Density gradient centri­ TMV-O activity was detected in frac­ fugation is a procedure commonly used tions {/ and b in the upper portion of the to separate a mixture of macromolecular gradient column, but fractions d and e components which differ in density, size, and the lower portion of the column and molecular weight. This method can contained a hi gh level of TMV-O activi­ be used to separate mixtures of viruses ty and produced many les ions on the from each other and from contaminat­ indicator species. From the<;e resl llts we ing non-viral components. Centrifuged conclude th at TMV-O sediments more gradient columns were analyzed and the rapidly th an CyMV and can be effective­ ultraviolet absorbing fractions separat­ ly separated from a mixture of the two ed. Each fraction was tested for biologi­ viruses. cal activity and observed in the electron Seedling Cattleya 'Bow Bells' crosses microscope to determine the size and were used in all bioassays. Plants were shape of the particles in the fraction. inoculated when buds were fully formed, usually 2 to 3 weeks before Results flowering. Inoculations were made by jabbing a razor blade contaminated with Three distinct fractions (a, b, and c) the test preparation into the pseudobulb were consistently present in fractionated of a budded lead and by rubbing the samples from 'Angel Island'. Fraction a preparation on the leaves. Flowers of contained mostly small particle contami­ plants inoculated wi th gradient fractions nants and short lengths of rod-shaped {/ and c did not develop flower necrosis. virus particles and a low level of CyMV This is probably because the concentra­ activity. Fraction b contained a high tion of CyMV was too low to produce concentration of flexuous rods which flower symptoms using the test were shorter than the normal particle procedure described. Flower necrosis of­ length of 475-480 mll described for ten appeared within 5 to 10 days after CyMV (I, 3). This fraction contained opening in flowers of plants inoculated the highes t level of CyMV activity. The with fraction b. The necrotic reaction predominant particle lengths in this progressed rapidly with severe necrosis fraction were '115 mu, 425 mu, 435 mu, becoming prominent 24 to 48 hours af­ and 445 mu. Fraction c contained about ter the first symptoms appeared. an equal number of particles 450 mu An experiment was carried out to and 475 mu long and contained a low determine if CyMV is tbe only virus in level of CyMV activity. Particle length fraction b measuring 400 to 500 mu long measurements were also m ade from vi­ and if it is solely responsible for induc­ rus present in unpurified sap. Ninety­ ing flower necrosis. A sample of fraction three percent of the particles in this type b was absorbed with CyMV antiserum to of prepar<1tion measured 435-460 mu in remove the CyMV particles from solu­ length. tion. Another sample of fraction b was In anoLh er ex peri men L, T1\IV-O \\'<15 treated with nonn<11 se rUlll. The samples purified from an orchie! plant tklt was were ill culJ :l ted ;11 3!i C ror 1 Itr. and fALL 1969 J77 centrifuged at 3000 g for 15 minutes. in the flower pot to prevent possible The preparation was left overnight in transport of the virus from one flower­ the refrigerator and recentrifuged the ing lead to the other. One lead was next morning. Tbe supernatant fluids inoculated with gradient fraction b were examined in the electron micro­ treated with CyNIV antiserum and the scope. A high concentration of virus par­ other lead was inoculated with the virus ticles was present in the virus solution suspension treated with normal serum. treated with normal serum (Fig. 1). Strong necrosis occurred 8 days after This result shows that normal blood flower opening in the lead inoculated serum does not precipitate the virus with fraction b treated with normal from solution. The virus suspension serum (Fig. 3). Fraction b trea ted with treated with CyMV antiserum showed CyMV antiserum did not produce the only a few virus particles in the superna­ necrotic flower reaction. Plants inocu­ tant fluid (Fig. 2). All of the particles lated with fraction b treated 'w ith TMV­ showed specific antibody attachment o antiserum showed necrosis in the flow­ along the surface. No reaction occurred ers. Leaves of some of the Cattleya along the particle surface in fraction b seedlings inoculated with untreated frac­ incubated with TMV-O antiserum and tion b showed sunken spots and necrosis the elec tron microscope picture ap­ 3 to 4 weeks after inoculation. peared the same as the sample treated with normal serum. Discussion A plant from a 'Bow Bells' cross with 2 R apid development of fl ower necrosis flowering leads was divided into 2 parts in experimentally inoculated Cattleya

(Top Left) Fig. 1. Electron micrograph of den­ sity gradient fraction b particles in­ cubated with normal serum (enlarged about 61,600X ). (Top Right) Fig. 2. Electron micrograph of den­ sity gradient fraction b particles in­ cubated with CyMV antiserum. Note specific antibody attachment along the surface of the particles (enlarged about 61,600X ). (Lower Left) Fig. 3. Flower necrosis in Cattleya 'Bow Bells' inoculated with gradient fraction I,. Photo taken 8 days after opening. PIIO"I U u. s. D JlI'.\IU »I E;';T OF AC IU ClJ LTlJI

178 AMERICAN HORTICULTURAL SOCIETY plants is correlated with density gradient mosaic virus problem in cattleyas. One fraction b which contains a higher con­ such article appeared in the Bulletin in centration of Cymbidium mosaic virus May, 1966. than gradient fractions a or c. Since The article "Viral Problems.in Or­ gradient fractions a and c contain some chids," states that Cymbidium mosaic CyMV activity, the rapid development virus "does not affect the bloom in any of necrotic symptoms may depend, at great degree but does show up when the least in part, on the concentration of flowers start getting old." It is true that virus in the original test preparation. virus-induced flower necrosis m ay ap­ The experimental finding that CyMV pear similar to symptoms of senescence alone can induce necrotic symptoms in that result from the natural aging proc­ Cattleya flowers requires a new assess­ ess. It is extremely important, however, ment of the virus problem in cattleyas to recognize that virus-induced necrosis and consideration of the following may appear within a few days after the points. flower opens and is different from 1. Diagnosis of the flower necrosis browning due to aging which in a virus­ disease can be simplified since only one free plant would appear only after a virus must be detected. An assay on the month to 6 weeks. host plant Cassia occidentalis can be The "discussion" above states that used to perform this test (1). However, plants infected with CyMV which pro­ bioassay for TMV-O should also be in­ duce necrotic flowers may be freed of the cluded since this virus can cause color­ virus by meristem culture. 50 far, this breaking in lavender Cattleya flowers. method of obtaining virus-free plants 2. Plants showing flower necrosis that cannot be used successfully in routine are not infected with TMV-O may pos­ production. Because of the large size of sibly be freed of CyMV by meristem the protocorms excised from Cattleya culture. Cattleyas have been freed of compared to Cymbidium, it has not CyMV by repeated excision of proto­ been possible to obtain virus-free cat­ corms when virus-free plants were not tleyas in a predictable manner. There­ obtained from the first excision. In con­ fore, it is essential to test and certify trast, TMV-O remains in small tissue virus-free nucleus stock plants if the pieces and is carried over in the new propagation and distribution of thou­ meristems even when very small pieces sands of virus-infected meristemecl Cat­ are cultured. tleya plants are to be avoided. 3. Cymbidium mosaic virus is reported to infect Cymbidium, Cattleya, and Literature Cited PhalaenojJsis (1,4,5). No distinction has I. Corbett, M. K. 1960. Purification by density­ so far been made between C)lmbidium gradient centrifugation, electron microscopy, mosaic virus isolates, and whether the and properties of Cymbidium mosaic virus. Phytopatholo gy 50: 346-35 l. flower necrosis disease is induced by a 2. Corbett, M. K. 1967. Some diSlinguishing single strain or a mixture of strains of characteristics of the orchid strain of tobacco this virus is unknown. ''''e do know that mosaic virus. Phytopathology 57: 16-!-172. isolates of the virus from Cymbidium 3. Gold, A. H., and D. D. J ensen. 1951. An electron microscope study of Cymbidium can produce necrotic flower reactions in mosaic virus. Am. J. Botany 38: 577-578. Cattleya (unpublished data) . It is, there­ 4. Jensen, D. D. 1950. Mosaic of Cym bidiu17l fore, important to recognize that al­ orchids. (Abstr.) PhytotJathology 40: 966. though flower necrosis may not develop 5. Kado, C. 1., and D. D. Jensen. 1964. Cymbidi­ in plants of some genera infected with wn mosaic virus in PhalllenotJsis. Phyto­ pathology 54: 974-977. CyMV, the same virus may produce ne­ 6. Thornberry, H . H., and M_ R . Phillippe. crotic flowers in cattleyas. 1964. Orchid disease: Cattieya blossom brown necrotic streak. Plant Dis. R eptT. 48: 936- Comments 940. 7. Thornberry, H. H .. M. R. Thomp on, K. Articles that have appearecl from time Izadpanah, and P. H. Canares. 1968. Orchid to time in the A05 Bulletin leave the vi ruses: Causality of Cattleya infect ious blos­ reader conrused a bOll t the C)lmbidi71m so m necrosis. Phyln/wtho/. Z. 62: 30!l-3 10.

FALL 1969 179 Weeds

This section on weeds is a new feature of the Arnerican H01"ti­ cu. ltuml Society's journal. Its editor is Dr. Loran L. Danielson, Leader, Hi eed Investigations, H orticultuml Crops, Agricultura I R esearch SeTvice, U. S. DepG1·trnen t of Agriculture, B eltsville, ]\I[G1-yland 20705. The purpose of this new service is to help Society rnernbeTS becorne knowledgeable about weeds and their coniwl.

WINTER WEED CONTROL aTvensis L.], shepherds-purse [Capsella An old axiom in the physical sciences buna-pa-storis (L.) Medic.], common tells us that nature abhors a vacuum. chickweed [Stellaria rnedia (L.) Cyrillo], When we think of weed encroachment, !lenbit [Larniurn arnplexicaule L.], and we know that this axiom is equally true many other emerge in the period from in the science of living things. Thus, we September through November in most see each open space between our domes­ climatic areas of the continental United tic plants quickly filled with weeds that States. Emergence occurs at specific times crowd and stunt them. Nature has a because of the rest period required by vast number of weed species ready at the seeds before germination or associ­ hand to fit into every seasonal, climatic, ated with reduced soil and air tempera­ soil, and cultural condition. As a result, ture levels and day lengths. With the ap­ the weed problem does not end with a proach of fall weather, we should plan change of seasons, but the species our weed control strategy and put it into change and the problem continues al­ effect as quickly as possible. most unabated. Two of the most common cool­ Cool-weather weeds such as annual weather weeds the home gardener must bluegrass [Poa annua L.], corn spurry contend with are common chickweed [Sp ergula arvensis L.], knawel [Scleran­ and henbit. Chickweed (Figure 1), also thus O1111I11£S L.], field madder [Sh em1"dia sometimes known as starwort or star-

Fig. 1. Three stages in the growth and develop­ ment of chickweed from the seedling on the left to the mature flowering plant on the right. Chick­ weed is a winter annual that germinates in the cool fall weather. It flow­ ers and matures some seed throughout the win­ ter, but the warm days of spring trigger maximuJIl seed production and se­ nescence. It is a low­ growing member of the pink family with a small, white flower having five petals.

180 AMERJCAN H ORTICULTURAL SOCIETY weed, is a winter annual weed belonging maturation occur throughout the winter to the pink family [Caryophyllaceae]. in many areas. Maximum germination occurs when Control of winter weeds without use night temperatures reach an average of of herbicides can be achieved by mul· 31bout 40 ° F, though scattered earlier ching plantings with black polyethylene germination occurs. Reproduction is mulch or tightly-woven burlap at the mainly from seed, but rooting at the time of germination. stem nodes and growth of the axillary Many of the germinating winter IJ uds prod uces addi tional plan ts when weeds can also be controlled by applica­ the parent plant is divided by cultiva­ tion of certain herbicides to the soil. tion, or when the stalk dies for any These herbicides include isopropyl reason. The stems are slender, averaging m-chlorocarbanilate [chlorpropham], 2- about Ys inch in diameter. They are chloroall yl dieth yldi th iocarbama te semiprostrate and spread out fanwise to [CDEC] , dimethyl tetrachloroterephthal­ a length of 6 to 8 inches from the main ate [DCP A], a,a,a-trifluoro·2,6-dinitro-N, stem. The simple leaves are opposite, N-dipropyl-p-toluidine [trifluralin], 2- (2 , ovate to oblong, and have a smooth 4-dichlorophenoxy) ethyl sodium sulfate margin. The sma.Ji, white star-shaped [sesone], and others. (These are generic flowers are clustered at the nodes. Flow­ names for trade-marked products.) Spray ers and seed are produced all during the treatments with these herbicides are effec­ winter each time the weather moderates. tive but must be carefully directed to Many seeds are produced in the single avoid contact with the ornamental foli­ capsule left by each flower. Chickweed is age. Granule formulations of the herbi­ a nitrogen-loving plant and is therefore cides should be used wherever available seldom found in unfertilized or waste­ because they minimize injury to the val­ areas. uable plants. Limitations of use on vari­ OtiS plant species differ from one herbi­ Henbit (Figure 2), also known as cide to another and are stated on the deadnettle and blindnettle, is a winter manufacturer's label. Rates of applica­ annual or biennial weed belonging to tion and other specific directions for use the mint family [Labiatae]. It repro­ are also given on the label on each duces from s~ecls and rooting stems as product. Read the instructions and fol­ described for chickweed. The slender, low them carefully to avoid injury to smooth, semiprostrate stems are square your plantings. in cross section, about Ys inch thick, and \Veeds often emerge and become es­ 6 to 8 inches long. The hairy leaves are tablished before we realize it. Such rounded to slightly lobed and palmately weeds can be safely destroyed in woody veined. The pink to purplish flowers are ornamental plantings by carefully di­ 111 axillary whorls. Flowering and seed rected ~prays of 1,I'-dimethyl-4,-4'-bipy-

6 Fig. 2. Three stages in the ~row h of henbit 5 from' the seed ing on th e left to mid vegetative on the righ'. Henbit is a 4 winter annual or bien­ nial r hat /Zerminates in 3 th -:! fall and grows, flow­ ers, and matures seeds 2 Ihroughoul the winler. It is a low-growing member of the mint family and has a pink to purple flower. 2 3 4 5 6 7 8 9

fALL 1969 181 ridinium sa lts [paraq uat] herbicide that as a means of minimlzmg weed prob­ thoroughly wet the foliage but do not lems. Also, large amounts of mulch often strike the ornamentals. give cover to woods mice that feed on the The soil should not be hoed or culti­ bark and roots of-ornamentals. Y

STA" I HIENT o r. OWNERSHIP, MANAGEMENT rily holders owning or holding I percent or more of AND ClRCULATION total amounl of bonds, mortgages or olher securities: None. (Act of October 23, 1962; Section 4369, Title 39, United 9. For completion by nonprofit organizations author­ States Code) ized to ma il at special rates (Section 132 .12 2, Postal I. Date of filling: October 1, 1969. Manual). . 2. Title of publication. The AMERI CAN HORTICUL­ The purpose, function, and nonprofit status " f this TURAL MAGAZINE. organiza tion and the exempt staus for Federa l income' 3. Frequency of issue: QUART ERLY . tax purposes have not changed during preceding 12 4. Location of known office of publication: 3110 months. Elm Avenue, Baltimore, Maryla nd 2 12 11. 10. Extent and nature of circulation: 5. Loca tion of headquarters or g"eneral busin ess offi ces A. Total no. copies printed of the publishers: 2401 Calvert St., N.W., Washington, (Net Press Run) 5,237' D. C. 20008. B. Paid Circulation 6. Names and addresses of publisher, editor, and 1. Sa les through dea lers and carriers, managing ed itor: street vendors and counter sales 0' 0" Publisher: The American H orticultural Society, Inc., 2. Mail subscriptions 3,844' 4,852" 240 1 Calvert St., N .W., Washington, D. C. 20008. C. Total paid circulation 3,844' 4,852 ' • Managing Editor: Elizabeth G. Eastburn, 240 1 Calvert D. Free distribution ( including samples) St. , N .W., Washington, D . C. 20008. by mail , ra rrier or other means O· 0·· 7. Owner ( If owned by a corporation , its name and E. Total distribution (S um of C and D) 3,844' 4,852" address must be stated and also immediately thereunder l ~ . OHice usc, left· over, unaccounted, lhe names and addresses of stockholders owning or spoiled after printing 1393' 248" holding 1 percent or more of total amount of stock. G. Total (S um of E & F-should equal 1f no t owned by a corporation, the na mes and addresses net press run shown in A) 5,237' 5, 100 " of the individual owners must be given. If owned by .. Average no. copies each issue during preceding 12 a partnership or other unincorporated firm , its name months. and address, as well as that of each individual must ·"Single issue nearest to filing date. he given.): The American H orticultural Society, 2401 I certify that the statements made by me above are Calvert St., N .W., Washington, D. C. 20008. correct and complet e. 8. Known bondholders, mortgagees, and other secu- EUZADETH G. EAsTBURN

182 AMERICAN HORTICULTURAL SOCIETY Garden Notes

A GREAT IRIS GARDEN Hower, lite ueardecL iris, IVhi ch he \\'a,) hybridizing. Since its inception in 1927, Presby Barbara W a I the r Gardens has been most fortunate in its has been hostess to unsalaried director, the gentle and per­ most of the famous severing Mrs, Barbara 'Walther. She was iris hybridizers of a well known lecturer on trees and wild our century. flowers who was singled out by the may­ or for the monumental task of making a dream become reality. By lucky chance, Presby Memorial Gardens is world she Ii ved next door to these grounds renowned as a repository of historical with her husband and children. and contemporary hybrid iris. The story Through all the years of the park's of its development could serve as a blue­ evolution she has never left the helm. print for any town which wants to orga­ Today Montclair is proud of and sup­ nize and maintain a successful botanical ports Presby Memorial Gardens by zon­ project. ing the grounds as a sanctuary and send­ The idea for this particular public ing city laborers and equipment to park in Upper Montclair, New Jersey help. To preserve integrity in the oper­ ation, Barbara-as friends call her­ came after the death in 1924 of Frank adhered to a motto, "Consider the iris H. Presby, a public spirited citizen who first." Although this accomplished many campaigned for more community trees of their aims and the display ran and flowers. He often said in his lec­ smoothly to all appearances, behind the tures, "In addition to ,vater supply and scenes many crises arose. sewage, Montclair should provide parks For one thing, there never seemed to to satisfy man's esthetic side." He en­ be enough laborers. To pay for overtime couraged everyone to grow his favorite work, private funds had to be solicited.

Streamers of iris beds unfurl their heauty in Presby Memorial Gardens, Up· per Montclair, New Jersey. Superb landscape design is hy Dr. John C. Wister. I'HOTO BY AUTHOR

FALL 1969 183 Some of the workers who came could not speak Engli h and Barbara conveyed diggi ng, dividing and planting oper­ ations with sign language, smiles and vigilance. Over the years, after employ­ ees mas tered skills, they were transferred or retired. Hardly a visitor was aware of it, but until a few years ago, no water was piped into Presby. Sustaining a great garden without a fau ce t wasn't easy. 'When the need was dire, a water truck was driven in. Luckily, long droughts can be tolerated by the rhizomes of bearded iris, the backbone of the plant­ ings. Other kinds of iris at Pres by, such as Siberians, Japanese and spurias which crave pre-bloom moisture, fared less well. At last hydrants were installed, but were placed inconveniently to some of Simple marker, placed in honor of the beds and in positions where visitors Frank H. Presby, in 1927, is encircled tripped on them. However, one can by brilliant bloOlns. PHOTO BY AUTHOR count on Barbara to arrange further negotiation. In the early yea rs, excess rain created she reae! tbat in moist areas of England a predicament worse than drought. they elevate perennial borders a little 'Water r an downhill and settled in the higher than the surrounding terrain. lower beds, causing fatal iris rot. Bar­ \Vhen Pres by's beds were raised with one bara undertook intensive rese arch until foot of additional so il, rot diminished. A real scourge came with the iris borer, j\l1aC1'onocllla onll sla, a wide­ spread pest along the Eas tern seaboard and else where in the U.S. The 'worm-like larva hatches in the spring from an egg that h as wintered over on old iris foliage or nearby plants. It tunnels into a fresh leaf, al wa ys an iris (although it will attack the blackberry-lily, B elamcanda ch inensis) , and then' eats undergrouml to fatten on the rhizome. -In its wake rot and often total plant des truction fo llow. Old fash ioned insec t­ icides and other methods proved so ineffective or costly that Barbara de­ veloped her own remedy-cutting back the iris foliage a ft er egg laying in November, leaving only six inches of greenery above the ground. Clippings and weeds were carted away, aborting millions of borers-not all, but enough School groups begin to arrive at the start of the iris season. Children from to keep them in check. the school across from Preshy call "At Presby the main task is organiza­ themselves the "guardians" of the tion," Barbara admitted with a sigh that park. PHOTO BY AUTH OR fleetingly covered a lifetime of labor.

184 AMERICAN HORTICULTURAL SOCIETY She referred mainly to the supervision of nel De Barry. ''It has been in bloom [or many volunteers who serve in various three weeks. Smell its fragrance." capacities without compensation. In another aisle she bends down to IIVomen from the Ioca J garden elu b :tddress a brown-toned modern hydrid, care for the 20 large beds- two to each "Good morning, Thounes!" To the lady bed-which they tend by checking iden­ walking alongside, she adds, "Th is was tifications, keeping records, printing and named 'Thotmes III' for a conrruering positioning labels, routing weeds, mak­ pharoah of old who fOllnd iris on his ing room for new arrivals and oversee­ campaigns and brought them back to ing the planting operations. They don't Egypt." consider it light housekeeping dllring She will not selec t a singI.: favorite but hot weather. The most exhausting chore is obviously partial to tall blue iris such is midsummer replanting of the as the Dykes winner 'Pacific Panorama'. rhizomatous iris, which are lifted, di­ Of whatever color, the famous ones are vided and replanted every five years on a all at Presby. rotating basis. Credit for the living muse um concept It is a tribute to Barbara that the goes to the first president of the Ameri­ workers accept tasks willingly and waste can Iris Society, Dr. J ohn C. Wister, who no time on petty jealousies, which scut­ came to the rescue with a three point tle so many club projects. If a novice master plan. At the start of Presby, he pleads ignorance of iris, Barbara tells desig-ned the handsome landscaping her, "I was like yo u when I started. without accepting a penny [or his pro­ We'll teach you." fessional services. Next, he donated rep­ A sea of beautiful blooms spanning resentatives from his private collection the history of iris reaches a peak each of historical iris, dating back to the 17th year, usually around Memorial D ay. century when the bees were the only Then the ladies of the staff become hybridizers. Last, he instructed Barbara hostesses to the estimated 5,000 visitors. to write to the leading- h ybridizers who Some of the admiring crowd don't know had known and respected Mr. Presby, to an iris from an orchid, others are ex­ persuade them to donate the newest and perts. Even city dwellers descend with best of their craft. cameras. It is a 40-minute drive from This suggestion was valuable because New York's ItVashington Bridge via currently there are over 900 reg-istrations Routes 80 and 46 (west), turning right a year and acquiring tbe most exciting on Valley Road, right on Mt. Hebron, of these is essential to sustain public and left on Upper Mountain Road. interest. However, each one averages $25 The sloping hillside is in full view of each, a prohibi ti ve price for Presby's the road, luring many passersby. All are small budget, which is contributed by welcome free of charge. the Montclair Garden Club and inter­ Barbara Walther dropped everything ested individuals. one spring day to give an impromptll By patient correspondence and negoti­ talk to a busload of underprivileged ation, thousands of cultivars were solic­ school children. On another day she was ited by Presby Gardens, with tbe only overjoyed to see a group of somber men­ recompepse to the nurseries an amount tal patients, brought on a therapy to cover packing and mailing costs. outing, responding with pleas ure to the IIVhen styles in iris change as rapidly many iris colors. as women's fashions, the commercial In the early morning a few fortunate growers discard thi ngs tha t are over ten friends inspect the nea t rows with Bar­ years old, but Presby continues to grow bara. the respected old ones. This has saved "ltVhat do you think of 'Violacea some [rom extinction and has spread the Grandiflora'?" she inquires, referring to fame of the gardens as a va lued reposi­ a cultivar in the historical section of the tory. garden. The label identifies the prolific Although Presby does not g-ive or ell clump as an 1856 introduction of Colo- iri s, it wi ll not turll down botanical

FALL 1969 185 gardens or breeders who want unavail­ In cultivation, it is adapted to sun at able items. In 1955 when another inter­ shade and to general garden soils. Here national iris garden was established in at Calloway Gardens we find it is best Florence, Italy, Barbara and her workers used in mass planting in a naturalized spent weeks packing valuable parcels. area, or combined in a border planting These sailed overseas and arrived safely. with other shrubs. Now Presby is the proud "parent" to the It is a native shrub of the Saxifrage world's second most important historical family, with only one species indigenous iris garden. to North America. Itea is the Greek In 1967, which was the LlOLh anni ver­ name -for willow, applied to this genus sary of Presby Gardens, Barbara Walther becau~e it has willow-like leaves and is, received three honors for her years of like willow, found near water. A medi­ service to Presby-the Special Achieve­ um-sized shrub, with upright spreading ment award from the National COllllcil branches 4-6 feet in height; deciduous, of State Garden Clubs, the Certificate of with alternate tapering serra te leaves, :Merit from the Garden Clubs of New 2-4 inches long. Jersey, and the coveted Foster Memorial The late spring or early summer flow­ Plaque from the British Iris Society. ers are creamy white, fragrant, and pro­ \'Vhen friends compliment her, she duced in dense spire-like clusters or ra­ insists, "It's not Barbara \tValther who cemes 3-6 inches long. Virginia sweetspire receives these awards but the town of is best known for its long racemes at Montclair, the Garden Club, the con­ small creamy white flowers and its bril­ tributing hybridizers, Dr. Wister, and liant autumn foliage. The leaves turn a the volunteer staff." rose red to brilliant red in early fall. Propagation is by seed, softwood cut­ Yet everyone knows who makes Presby tings, or division. what it is, and that is why the rainbow Six or more species of Itea inhabit on the hillside is unofficially called '"Bar­ tropical and subtropical Asia. I tea ilie-i­ bara's garden." folia, hollylea£ sweetspire, a native of GORDON BLACKWELL central China, has attractive, partially 377 Marblehead Road evergreen, holly-like, spiny-toothed foli­ Tuckahoe, New York 10707 age. The small white flowers are 6-8 inches in length, in terminal dropping Itea virginica-Virginia Sweetspire racemes. Unfortunately, it is not as or Virginian Willow hardy as I. viTginica and is seen more Virginia sweetspire is native in low, frequently on the \tVest Coast than in wet habitats from New .Jersey and Penn­ the East. sylvania to Florida and Louisiana, and F. C. GALLE is often associated with the Coastal Calloway Gardens Plains. Pine MOllli Loin, Georgia 31822

Itea virginica- Vir­ ginia Sweetspire or Virginian Willow

PHOTO BY AUTHOR

186 AMERICAN HORTICULTURAL SOCIETY Carpenteria cali/ornica Jy, for instance, plants that are aquatics but are also rampant growers in very dry 1 would like to comment upon the soil. cold-hardiness of Carpenteria cali{ornica For the true plantsman, the challenge as described in Part I "Useful California is in doing the difficult! Natives for Gardens," page 338, Ameri­ MILAN RAFAYKO can HOl-ticultuml Magazine) Fall, 1968. 401 B Cente?' StTeet The Booh of Shnlbs, by Hottes, states n erea. j{(' lIll1cl:y 4(J1(J} that C. californica is hardy in Phila­ delphia; this is not the usual statement llemerocallis for Dark Patios referring to zone hardiness, but merely Our patio is densely shaded, and by an observation that a plant was actually July becomes rather like Poe's "dank growing there, and thriving. tarn of Auber." Begonias and Impa­ Plant hardiness is a many-faceted liens sprawl and expire pallidly, and we thing, cold-hardiness being but one fac­ have given up moving potted flowers in tor of many which determine not just and out of the shade. By hazard this survival, but normal, healthy growth; summer we came upon a spectacular many plants can survive if pampered, solution when we were dividing our but are not really thriving; and if left to daylilies in full bloom. Instead of the vagaries of climate, would soon give throwing the surplus plants aside, I up the ghost. stood them in tubs, stuffed the roots with Such arid region plants as C. californi­ peat and Perloam, and watered them in ca, when grown in regions of ample with a mild fertilizer solution. Presto-a rainfall, must be in well-drain ed-in fairyland! fact, sharply-drained-soil. Every bloom opened perfectly over The flora of the arid west does not, as several weeks. The plants continued a general rule, tolerate the climatic con­ green and fine, and were in perfect ditions and soils of the eastern and shape for replanting when they finished southeastern United States without pam­ blooming. The effect of those great lav­ pering and special site preparation. ish sheaves of bloom, glowing in the shade in every color from lemon-green Arid region plants are characterized to crimson, was magical. Even mediocre by grayish leaves with pubescent under­ varieties looked so elegant I hated to surface, a survival mechanism to retard give them away. water loss due to transpiration. The beauty of the system is: no work. Arid region soils have high pH, while One merely digs the hems a few weeks the soils of regions with ample rain are early. Tubbing takes only a moment. below the neutral point and are any­ Hems are not fussy about losing a few where from mini-acid to acid, depending roots or having air pockets, and this is upon the parent material. their time for making new roots anyway. However, these comments arc not to be The rest of the year they can grow in the construed as meaning that we should vegetable row, or any sunny spot, in the not attempt the growing of arid region normal way, with none of the bother of plants in the east, or for that matter, any potted plants. exotics away from their normal environ­ If you decide to try this, water lavish- ment. If we followed th is pri nci pie we 1)1) and of course be sure there are drain would have nothing in our gardens, for holes. Choose cultivars that stay open in almost all of our cultivated plants are the evening, and avoid the frosted pinks exotics from varied climatic and soil which require full sun to blanch the environments. This is merely an effort to pigments. Be sure to try reds: you will point out to less experienced plantsmen never see them so gorgeous in the open the several factors involved in the cri­ garden. terion of plant hardiness. ALICE B. SHE LDON Many plants are very adaptable, and 6037 Ramshom Pl. can be acclimatized easily, even amazing- McLean, ViTginin 22101

FALL 1969 ]87 Book Reviews

Tr(>('s research a lld development information, con­ tinues to -stand as the most definitive book Andreas Feining-er. Viking Press, 625 on plant propagation available. While iot Madison Ave., New York, N.Y. 10022. serves ,as an excellent college or university 1968. ]]6 pages. lllustrated. $22.50. (Li­ text, it should also be on the shelf of every brary) reference library that is concerned with The author, a renowned professional pho­ plants. tographer, states in the introduction that he The chapters .are divided into five -sec­ " ... had set my mind on a new kind of ·tree tions: General Aspects of Propagation, Sex­ book-a project that had kept me occupied ual Propagation, Asexual Propagation, Spe­ 0 11 and off for the previous 9 years-not a cial Methods, and Propagation of Selected textbook or manual, nor a tree identification Plants. Wherever appropriate, the technical book, nor still another picture book proving phases of reproduction and propagation are that trees are beautiful, but a tree­ discussed, such as environmental condi tions, appreciation book". or the anatomy and physiology of the plant. He has produced a beautiful large-format These chapters are ,then followed by those volume which largely fulfills his aim. The covering the techniques of propagation, outstanding feature of the book is 160 su­ which contain good illustrations that further perb full-page photographs (40 in color) of add to their usefulnes-s. A most important 67 tree species . These have been photo­ addition is ,the chapter on Aseptic Methods graph ed primarily in North America. The of Micro-Propagation concerned with em­ book is divided into 16 chapters which treat bryo culture, tissue culture and shoot tip or various aspects of trees (structure, trunk and meristem culture. These newer techniques bark, wood, the forest, etc.) and some dis­ are becoming of greater importance in tinctive species (bristlecone pine, live oak, -studies on plants, ·and from .a very practical the two sequoias). Considering the broad horticultural .point are essential in order to scope of this tree-appreciation book, I won­ obtain certain disease free plants. der why the vital aspects of flowers, fruits, and seeds are not discussed or illustrated. A For ,the student who wishes to study in final chapter urges individual participation greater detail, extensive bibliographies are in co nservation efIorts and describes the included. The perlSon who only wants to major national conservation organizations. propagate a plant will find the eha pters on the Each chapter is followed by a group of techniques carefully written; or he may turn a ppropriate photographs. T he captions to the final chapters ,that provide specific precede each group of photogra phs; I would information on the propagation of fruit and have found them more useful had they been nut species, o n ornamental trees, shrubs and on the same page as the corresponding pho­ vines, and on selected ·annua15 and her­ tograph. baceous plants. It would be good to see ,this book reprint­ CONRAD B. LINK ed in a less expensive, paperback edition so that it might have wider distribution. The Handbook of North American awareness and appreciation of trees and the role they play in our lives is an important Nut Trees part of the respect for the whole natural Richard A. Jaynes, Ed. Northern Nut environment which is increasingly vital for Growers Assn., Inc., 4518 Holston Hil's life in our urbanized socie ty. Road, Knoxville, Tenn. 37914. 1969. 421 ROBERT L. BAKER pages. Illustrated. $7.50.

Plant Propagation, Principles and An excellent reference for the many kinds Practices, Second Edition of nut trees that can be grown in Canada and the continental United States. Hudson T. Hartmann and Dale E. Kester. Prentice-Hall ]nc., Englewood Cliffs, New Dr. .Jaynes, associate geneticist, Connecti­ .J ersey 07632. 1968. ]11 ustrated. 702 pages. cut Agricultural Experiment Station, is edi­ $14.00. (Library) tor of this volume which contains contribu­ tions from twenty-four additional and equal­ This second edition, with its added recent ly well known specialists.

188 AMERICAN HORTICULTURAL SOCIETY The techniques and problems in culturing This is a book which a beginner will find and developing better nut tree cultivars are helpful, and the more advanced bonsai the main subject of this handbook. The book enthusiast will use as a rderence. is divided into four major sections, consist­ CONRAD B. LINK ing of thirty-two chapters. Part I is an introduction and history of The Lily Yearbook, Vol. 21 nut trees. George L. Slate, Eel . North America n Lily Part II covers culture and propagation Society, Fred N. Abbey, exec. secy ., North and includes chapters on soil management, Ferrisburg, Vt. 05473. 1968. 197 pages. pruning, mulching, herbicides, control of $7.50. (Library) mammal and bird damage, plant pests (in­ sects and diseases) , and labels. A:nother in a series of well prepared year­ Part III, The Tree, emphasizes the pro­ books on the lily, an important garden duction of thirteen major nut trees includ­ plant. It includes cu],tural ·articles which. ing pecans, walnuts, chestnuts, almonds, provide growers with guidance in such are,,_ coconuts, cashews, macadamias and as the effects of herbicides, seed germin ation, pistachios. A chapter en titled "Oaks, Beech, growing lily seedlings, and control of root Pine and Ginkgo" completes this section. lesions. It also has articles on breeding and Part IV includes dupters on nut trees for genetics; on the new Barber lilies, hybrids of planting for wild life; breeding, naming, Lilium p1l1nilum; and hybridizing experi­ judging, cleaning, storing, and cracking nuts. ments with Lilium 'Black Beauty'; and a This handbook is a valuable reference and report on the western native lilies. As a should increase the interest in nut trees, yearbook of a specific -plant society, it in­ contributing to their more widespread use cludes society informa:tion, and stories of and efficient production. people who have contributed to the informa­ F. C. GALLE tion and development of the lily. This issue also contains the cumula,tive index to the Lily Yearbooks from Vol. 7 (1954) to Vol. 20 Bonsai, Saikei and Bonkei (1967). Robert L. Behme. William lVlorrow and CONRAD R. LINK Co. Inc. 425 Park Ave. S., New York, N.Y. 10016. 1969. 256 pagelS. Illustrated. $9.95. Ficus: the Exotic Species (Library) Ira J. Condit. University of California, Division of Agricultural Sciences, Berk­ Bonsai is a technique of growing plants eley, Calif. 94720. 1969. 363 pages. Illus­ that continues to intrigue certain gardeners. trated. $4.00. (Library) This is a non-technical, easy to read book on the ,topic. The author develops the subject This ·is a technical publication on an with well chosen illu5trations to support the important plant which includes many species text. He includes a few pictures of natural that have ornamental value and are useful plan ts, or plan tings, that could serve as in landscape plantings in tropical countries. models for growing ,and training bonsai. The It is based on 'the author';; many years as a author seems q ui·te practical in suggesting research scientist at the University of Califor­ so ils and materials that are available, and nia at Riverside. For the nurseryman and although he mentions some of the less avail­ landscape gardener the keys for identifica­ able ,types of fertilizers used by the] apanese, tion, with description and ob;;ervations of he also recommends liquid, readily available the .author and other sources, will probably kinds such as those used for house plants. be of the greatest value. The author has The development of tray landscapes is less included an extensive bibliography and de­ common. Saikei includes live plants and scription of the genus itself, including its Bonkei is a "dry" landscape without living growth, flowering, and fruiting habits. Wher­ plants. Such developments are naturally ever it is known the author h as also included rel ated to bonsai because of the size of the the name of the insect associated with the plants and their relation to the landscape on fruiting. This work will be a standard refer­ a miniature scale. They require skill and ence on the genus. im:lgination to c1 evelop. CON RAD B. LINK

October 30, J 969

FALL 1969 189 Index To Volume 48 Numbers in italics ,-ete,- to illwtTCItio"lls.

A for COlumeJ.-ci.a1 Plant de Graaff, Jan: Growing, 37 Achillea m illefoli!lln 'Corona­ A New Era in Hybrid Lilies, Book Reviews, 45, 94, 143, 188 110 tion Gold', 7 bottlebrush grevillea, 150 Delphinium, Pacific strain, 55 , Advances in Horticulture, 37, Box Huckleberry-A Much 56 81, 129, 175 Neglected Native, 70 'Blue Jay', 53 African Violets from Colchicine­ Brewbaker, J . L.: 'Elaine', 56 treated Cuttings, 38 Tropical Sweet Corn, 81 Dicentra spectabilis, 9 All-America Selections, 1969, 34 Brown, Emily: Disa un if/om, 138 Allen, P. G.: Bergenia stracheyi 'Alba', 87 Dodder, 42, 43 Recent Developments in Dodecatheon meadia, 5 Producing More Crops on C D,-yandra formosa, 152 Straw, 175 CamjJanula gaTganica, 9 Almond Capsella bursa-pastm-is (L.) 'Prairie', 132 Medic., 180 E Andmpogon gera,-dii var. CarpenteTia califomica, 187 Echinacea pW'puTea, 6, 10 cll1-ysocomus, 10 Cassia occidentalis, 179 Echinacea pUTpurea 'Robert Anthtl1'ium Cattieva Bloom', 8 'Marian Seefurth', 82 '.;\ngel Island', 176 Egolf, Robert L.: ' Uniwai', 82 'Bow Bells', 177, 178 Proteads-A Gardener's Arisumi, Toru and L. C. Frazier: Ceallothus Challenge, 148 New African Violets from cuneatus, 26 Embothrium Cholchicine-trea ted Cu ttings, gloTiosus, 29, 30 coccineum, 154 38 g,-iseus, 28, 29 English Holly, Nutrition of in A,·temisia vulgaTis (mugwort), griseus Oregon, 67 134 'Louis Edmunds', 28, 29 Environmental Protection, Na­ Aster X 'Mills Glory', 29, 30 tional Policy of, 146 'Morden Cupid', 129 pU,-pll1"eUS, 29 Eucalyptus 'Morden Fay', 129 Cedar, George 'Vashington caesia, 63 Memorial, 87 camalduiensis, 63 , 65, 66 B Cedrus libani, 87 ci triodora, 63 Baldwin, J. T ., Jr.: Chenopodium amarantic%r, cinerea, 63 An Unusually Corky Sweet 176, 177 cladocalyx, 63 Gum, 88, 142 chickweed, 180 erythroco,-ys, 63 Cleye,-a jajJonica [or Screen Cimicifuga racemosa, 8 {lci/olia, 63 Planting, 90 Cleyera japonica, 90 globulus, 62, 63, 65 Cryptomeria jajJonica, A Dis- Colors, Flower, 159, 163 lehmannii, 63 tinctive Coniferous Ever- Coneflower, pink (Echinacea polyanthemos, 63 green, 43 ptl1'purea) , 6 "obusta, 66 Metasequoia Produces Male Corky Sweet Gum, An Unusu­ mdis, 63 Flowers in Williamsburo-, ally, 88, 142 saiigna, 62, 63, 66 Virginia, 137 " corn spurry, 180 sidemxylon, 63 Banksia g"I-an d is, 150 Crabapple viminalis, 63, 66 stJeciosa, 152 'Almey', 129, 132 Evans, Morgan: Baumgardt, John Philip: 'Royalty', 132 Eucalyptus at Disneyland, 62 Perennials for Mid-'Vestern rosybloom 'Garry', 129 Gardens, 4 ro>-ybloom 'Selkirk', 129 F Begonia boliviensis, 52, 54 Crops on Straw, Recent Develop- jJearcei, 52 ments in Producing More, Fertilization of Trees, Shrubs. tuberous, double roseform, 5-1 175 FiclIs microcarpa var. nitida, 172 tuberous, Picotee roseform, 55 _C'-yptome"ia japonica, 43, 44 and Woody Groundcovers, tuberous, rumcd camellia, 5-1 ' .C)!!n bidium virus, 176, 179 57 veitchii, 52 Cumming, W. A.: field m adder, 180 Bergenia Ornamental Horticulture in Film Festival, The American 'Bellawlay', 88 Prairie Canada, 129 Horticultural-After Five stracheyi 'Alba', 87, 88 Years, 31 Bitter Tree, Rare Korean , 92, 93 D Fisher, Robert B.: Black-eyed susan (Rudbeckia Danielson, L. L.: George vVashington Memorial hiTta) , 5, 123 Control of Dodder in Home Cedar, 87 Blackwell, Gordon: Gardens, 41 Flower Colors and Color Fans. A Great Iris Garden, 183 Controlling Mugwort in 158 Bleeding-heart (Dicentj'a Woody Ornamental Plant­ Foster, H. Lincoln: spectabilis) , 9 ings, 134 The Double Bloodroot, Bloodroot, dou ble (see Controlling Poison Ivy Sanguilla"ia canadensis Sanguinaria Cfllladf'llsis) , Around the -Home, 84 ' Multiplex', 139 139 Stinging Nettle--A Garden Fmnklinia alatamahn, 41 bluegrass, annual. 180 Problem, 85 FTI:montia Boodley, J ames vV. and Winter Weed Control, 180 ca lit01"1lica, 25 , 26 Raymond Sheldrake, Jr.: Daylilies (see Sheldon, Alice B., su bsp. napensis, 26 Cornell Peat-Lite Mixes 187) X 'California Glory', 26, 27

190 AMERICAN HORTICULTURAL S'OCIETY G J saTgentiae, 11 8 Calle, Fred C. : Juniper, creeping speciosum, ll6, ll8 Guest Editorial-Standards in 'Prince of Wales', 129 stJeciosu m 'R ed Champion', Horticulture, Spring issue J L1nipems h01'izontalis 112 Itea virginica-Virginia Sweet­ 'DwlVegan Blue.', 130 sulphureuln, 11 8 spire ~ Vi.rginian Willow, K szovitsianum, 117 186 Kamemoto, H . and H . Y. faliense, 115 Garden Notes, 137, 183 Nakasone: umbel/alum X L. ligrinwn, Gardeners' Notebook, 40, 87 .\nthuriums, P astel- Colored, 11 4 Gaylussacia bmchycem, 72, 73, 82 'Umbtig', 11 4 75 king protea, coyer illustration, Liquidambar slymciflua, 88, 89, Gemniwn grandiflO?"'U1n, 9 Fall 142 Gevuina avel/ana, 149 knawel, 180 L ythrwn Gi lbert, J . C.: Korean bitter tree, 93 'Morden Gleam', 129 Disease Resistant Tomato 'Morden P ink', 129 Hybrids, 83 L Gloriosa Daisy (see Rudbeckia M h iTta, 124) L amiLim amtJlexicaule L., 180 Macadamia integrifolia, 81, 148, Goldenrod, 5, 10 Laurel Fig, 172 155 GomtJh1'ena globosa, 176 "Laurel de la India", 172; back MalLIS G1'evillea petrophiloides, 150 cover, Fall 'Roya lty', 130 Tobusta, 148, 149 Lawson, Roger: Meader, E. M.: Flo wer Necrosis in Caltleya R are Korean Bitter Tree Orchids, 176 H T hrives in New H ampshire, Lees, Carlton: 92 H aliea I(lLirina, 150, 154 Pilot Garden of Roxbury/ Mellinger, i\{ arie B.: H all er, J ohn M,: Dorchester, 133 Looking for the Lost Frank­ Laurel Fii\-An Exceptional L eucadendron argenteLlm, 148, linia,40 Sh ade Tree, 172 l SI, 154, 155 The Rare Oconee Bells, 91 Tree As Air-Conditioner, 79 LeLicospe1'lnwn gmndiflorum, M etaseqUOia gl)'ptostroboides, Hamilton, R. A. and P. Ito: 156 137, 138 'Sunrise Solo'-A Differen t 1'eflexLI Ill, 155 Mockorange Colored Solo P apaya, 82 Liat1'is, 10 'Aubrey', 129 H amilton, R . A. and H . Ooka: Lilac i\Iorden R esearch Station, Macadamia in tegrifolia, 81 'Coral', 129 Canada, 129 Hawaiian Introductions, 81 'Miss Canada', 129 Morrison, B. Y., second i\ [cmo· H awthorn, 'Sn owbud', 129 'Redwine', 129 rial Lecture, 100 'Toba', 129, 132 'Royalty', 129 i\Iugwort, 135, 136 H elianthus annU!lS, cover illus· Lilies, A New Era in H ybrid, tration, Winter llO N Hemerocallis for Dark Patios, Lilill1n atlmtLlm, 11 6 Natives, Useful California, for 187 var. vi1'ginale, 11 8 Gardens (Part II), 25 hen bit, 180, 181 A Ul'elian h ybrid, 11 8 Necrosis, Flower, in Cattleya Heteromeles arbutiJolia, 140,141 Bellingham hybrid, 11 4, 11 6 Orchids, 176 var. nwc1'ocartJa, 14 1 'Black Beauty', 11 8 Nettle, Stinging-A Garden H euchem 'Brandon Pink', 130 bulbife1'Um, 11 4 Problem, 85 H eutte, Frederic: bulbiferum var. crocewn, 11 4 Nicotiana tabacum 'Xan th i', 176 Guest Editorial-America X 'Bu,ttercup', 113, 116 Calls for "Educated ceTnuu In, 112, 11 4 o Muscles", 98 X elegans, 11 4 Oconee Bells, The R are, 91 Holly, English (see Ilex X 'Enchantment', 113 Orchid , red (see Disa uniflo'l'a) aquitolium) , 67 hansonii, 111, 11 8 Orchids, Flower Necrosis in H orsb rugh , Patrick: henryi, 11 8 Caltleya, 176 Emotional, Ethical, and X hollanriiwm, 11 4 Ornamental Horticulture in Ecological R esponsibilities 'Imperial Crimson', Cover Prairie Canada, 129 toward the Environment, illustration, Summer 100 japonicum, 116 p H osta 'Royal Stan dard', 9 J amboree strain, 115 Papaya l

FALL 1969 191 augustifolius, 170 "Vestern Horizons in Tuberous Sweetspire, Virginia, 186 aura tor, 170 Begonias, Polyanthus Prim­ Systemics, A New Tool for the barbatus, 168, 170 roses, and Delphinium, 52 Home Gardener, 12 caespitosus subsp. Rhus mdicans, 85 desertipicti, 167, 170 Rosa 'Assiniboin e', 130 T cobaea X P. tTifiorus, 167, J 70 Rose TelojJea speciosissima, 149, 156 dasanthera, 170 ' Prairie Dawn', 129 Ticknor, R. L., A. N. Roberts, eaton ii, 167 'Prairie Youth', 129 , 132 and O. C. Compton: elimigem, 170 'Therese Bugnet', 132 Nutrition of English Holly ericopsis, 170 Roupala mac·rojJity lia. (!lex aqltifoliul11) in Oregon, Fa sciculaTis, 170 'Corcovadensis', 149 67 'Fire bird', 170 R'lld beclda, Horticul tural Tomato, Disease Resistant 'Fire Kino" 170 Opportunities in, 119 H ybrids, 83 'Garnet', 170 caZifomica, 120, 122 Toyon, 140 glaber, 167, 169, 170 fu.lgida, 123 , 124, 126, 127 grandiflorus, 167 graminfolia, 123, 124 u Henry hybrid, 167 grandifiom, 123 , 124, 127, 128 UTtica clioica, 85, 86 X P. munayanlls, 169 heliopsidis, 123, 124 habroanthus, 170 hiTta, 5, 119, 123, 124 v havaTClii, 167 Zaciniata, 119, 120, 121 X johnsoniae 'Bennett', 168 laciniata 'Hortensia', 120 Va ccilliui11. brachycenl1n, 72 Van Melle, Peter excerpts !!!Inthii, 170 maxima, 120, 121, 122 J., from, 11 , 19, 24, 30, 69, 80, labrostls, 170 m.issotlfiensis, 123 , 124, 127 128, 166, 171, 174 larici/olius, 170 171ohTi, 120, 124 Ve'monia-A Useful Native for liniamides, 170 mollis, 123, 124 'Mesa', 169 nitida, 120, 122 Gardens, 76 Venwnia mUTTayanlls, 169 occidentalis, 120, 122 acaulis, 78 nitidus, 170 subtomentosa, 123. 124 altissirna, 76, 78 palmui, 167 hiloba, 123, 124, 125, 126 angusti/olia, 77, 78 IJeltanthem, 169, 170 'Prairie Dawn', 169, 170 S /Ja Idwin ii, 78 'Prairie Dusk', 169 blodgettii, 76, 77, 78 Saini/Jalliia 'Nature Boy', 39 crin ita, 78 'Prairie Fire', 169 Sangvinaria. canaclensis, /asciculata, 78 'Prairie J ewels', 169 'Multiplex', 139 flaccidifolia, 78 'Ruby King", 170 Schmidt, Marjorie G ,: secundifloT71s, 170 g,igantea, 78 Toyon, Heteromeles glauca, 78 strictus, 169. 170 n,'butifolia, 140, 141 inteTi01-, 78 1ltahensis, 170 Useful Calirornia Natives [or iettennannii, 78 Penstemons, My Friends the, Gardens-P art n, 25 linclheimeri, 78 167 ScleTanthvs annllllS L., 180 1nm'ginata, 78 Perdue, Robert E., .II'. : i\ fu gwort, 134 missU1-ica, 78 Horticultural Opportlln itics Jeibert, Russell J.: noveb01-acensis, 78 in Rudbechia, 119 The American Horticultural ovalitolia, 78 Perennials fo r Mid-"Vestern Film Festival- AEter Five fJulcnelia, 78 Gardens, 4 Years, 31 texana, 78 PiC1'asma quassioides (see Bitter C uest Editorial-Role or Viehmeyer, Glenn: Tree, Korean) , 92 , 93 Plants in Curbing Air My Friends the Penstemons, PflalaenolJsis, 179 Pollution , Winter issue, 3 167 Pincheny Sheldon , Alice B,: 'Stockton', 129 Heme1'Ocallis for Dark Patios, W Plum 187 " ' aratah, New South ' '''ales, 156 'Muck le', 129 Trees From Pot Plants, 89 TVashington Post, The: Poa annua L , 180 Sfleraniia anJensis L., 180 Gues t Editorial-National Poison-!vy, Controlling Around Shooting star (Dodeeotheon Policy of Environmental tne Home, 84 meadia) , 5 Protection, 146 Potentilla fruticosa. Sh01·tia ga lacifoZia, 91 " ' atson , Donald P.: 'Coronation Triumph', 130 silver tree, 154 Hawaiian Introductions, 81 Presby IVf emorial Gardens, 183 Smith, Hazel and Don: "Veed Control, Winter, 180 Primrose, polyanthus, 56 Box Huckleberry-A Milch Weeds, 84, 134, 180 Cover illustration, Spring; Neglected Native, 70 TVeigela back cover, Summer Solidago, 10 'Centennial', 129 Pmtea ba1'bigera, 157 'Cloth of Gole!', 7 'Wikle, Jack: cyna1'oides, 155; Cover illus­ slJeciosa. val'. angllslala, 5 Fertilization of Trees, Shrubs. tration, Fall SjJ ergula ame'llsis L., 180 and ''''oody Groundcovers, obtusifolia, 153 Spruce, blue 57 Tepens, 153 'Morden', 129 Willow, Virginian, 186 Proteads-A Gardener's Stellm-ia mer! ia (L.) Cyrillo, ' ,Vister, Gertrude S,: Challenge, 148 180 The Hybrid Cherry 'H ally Prunlls Slenoeo1'iJlIS si17uallls, 148, 155 J olivette', 44 'I-Ially Jolivette', 11 Stormon, John A.: The International Peace y R Garden, 20 Rarayko, Milan B.: Straw, recent developments in Youngman, "Vilbur H.: CaTpenteria cali/omica, 187 produ{;ing more crops on, Systemics, A New Tool for Reinelt, Frank: 175 the Home Gardener, 12

192 AMERICAN HORTICULTURAL SOCIETY THE AZALEA BOOK Second Edition

by FREDERIC P. LEE

This handsome book tells everything there United States Department of Agriculture. is to know abollt azaleas, incorpora ting the Part J I thoroughly covers basic horticul­ most recent c1e"elopments in cultural prac· tural-plant structure, growth factors, soils tices, the latest methods of treating diseases and nutrition, with step-by-step procedures and pests, and the best of the new imported for hybridizing. and domestic azalea varieties. Part III considers the place of azaleas in Here is botanical and historical informa· the plant world: relationship to rhododen­ tion of immense interest to the scientific ex· drons; distribution and classification, with pert as well as complete know·how for en­ detailed descriptions 'af Ghent, Mollis, Ku­ thusiastic amateurs on selecting, planting, rume, Belgian and Southern Indicas, Gable, fertilizing, and pruning azaleas-whether Glenn Dale, and many other azalea groups, they be evergreen or deciduous, 6-inch dwarf together with their origins and history. or 10·foot giant. There is also a revised classification and de­ The vast knowledge of plant explorers, scription of some of the American and Jap­ government specialists, and foreign collectors anese species and a thorough revision of the is embodied in this authoritative book. Satsuki group. Sponsored by the American Horticultural Part IV offers a complete index of de­ Society and successor to its Azalea Hand­ ciduous and evergreen azaleas, with notes on book, this volume reflects world experience habit, blooming period, flower type, size, with azaleas, and also contains the consider­ and color. The list of azalea breeders and able practical knowledge of Frederic Lee, nurserymen in America, and their contribu­ who himself continually tests some 500 azalea tions to azalea culture has been fully up­ plants in his Maryland garden. dated. International registration proceedings Part I is a complete garden guide, with are discussed, and the list of trade sources information on planting and care, hardiness, extended. A table cataloging registered companion plants, propagation, indoor cul­ azaleas is also included, as well as several ture, and directions for bonsai plants. In ad­ lists of recommended varieties. dition, plant hardiness has been keyed to 408 pages, 6% x 9%. 65 illustratIOns, 5 in the new Plant Hardiness Zone Map of the color. Publisher's price, $12.00 plus postage.

The American Horticultural Society, Inc. 2401 Calvert Street, Northwest Washington, D. C. 20008

Please send me ______copies of The Azalea Book, 2nd Edition $ ____ . __ . ______. is enclosed. Price to non-members $12.00, plus 40¢ for postage and handling. Price to Society members $8.50, plus 40¢ for postage and handling.

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