Contents ______

Remembering . • • • • • • • • • 3 fluercus rotundifo/ia Lam. and its forn•s in Oak Tree Hybrids in the Bejan Ext1·emadura, Spain ...... 3 9 Forest ...... 5 Oaks in Belgium: Text of a The Great Oak of the Landis Slide Presentation Made at Arboretum ...... 11 the Arboretum Trompenburg, July 3, 1999...... S3 An Oak Wilt Primer ...... 14 Author's Guidelines...... 59 Oaks of the Chihuahuan Desert Region ...... 21

.lntemational Oakr is edited and designed by Russell K. Stare, Auburn, Illinois ~bout the Cover ______Our cover shot this issue features a {]. emoryi located in the Lost Canyon of the Gila River, New Mexico. Elevation 4,600 ft. Oak specimens in the Gila River area and other parts of the Chihuahuan Desert Region are highlighted in Michael Melendrez' article beginning on page 21. ©Guy & Edith sternberg

Anyone interested in joining the International Membership dues are U.S. $15 per year, and Oak Society or ordering in.fomzation should benefits include publications, conferences, and contact the me11zbership office. exchanges of seeds and information among members from 30 nations on six continents.

International Oak Business office: Editorial office: Membership office: Guy Sternberg, President Doug McCreary International Oak Society Starhill Forest Integrated Hardwood c/o Richard Jensen Route 1, Box 272 Range Mgt. Program Department of Biology Petersburg, Illinois 62675 University of California Saint Mary's College USA 8279 Scott Forbes Road Notre Dame, Indiana 46556 e-mail: Browns Valley, California USA [email protected] 95918 e-mail: USA [email protected] e-mail: [email protected] International Oaks

by Guy Sternberg Starhill Forest Arboretum NAPPC Oak Reference Collection Petersburg, Illinois USA

he fu·st paper that appears in this issue of Interna­ tional Oaks was condensed frotn the 54-page doc­ toral dissertation of our late n1en1 ber Dr. Augustin Stanciu, who died shortly after its completion. A synopsis of this research was published in 1997 by the Museum ofDeva, Ron1ania in Acta Musei Devensis, Sargetia Series Scientia Naturae XVli, as Oak Tree Hybrids in the Bejan Forest, Deva: Reactualization and Genetic Prospections. This publication was very helpful in translation. The original title of Dr. Stanciu's dissertation, completed in Romanian for the Uni­ versity of Transylvania in Brasov under the supervision of Professors Stanescu and Sofletea, is C er ce tari Ta xo non1i ce , Mor.folog ice si Ecologice Privind Hibrizii Genului Quercus tlin Rezervatia Stiintifica Bejan, Deva, Judetul Hunedoara. The Scientific Re­ serve Forest of Bejan is famous for the

broad association of Augustin Stanciu (lefi) with Stelian Radu (ceo­ oak species and hy­ ler) and Guy Sternbe1g (right) in Forest Bejan, brids found there, and JudI lunedoara, Romania, June 1995. has been tnentioned in contd. on pg. 4

No.ll I Fall 2000 Page 3 International Oaks

• • • contd . from pg . 3 several prev ious issues of International tnagnificent places, at least in the eyes Oaks. Probably no other forest in Europe of an oak student. We picked up contains such a rich and genetically di­ August in ~ traveled north to Bejan, and verse oak flora; and certainly no other tnet Dutnitru at the entrance to the person kn ew the oaks of Bejan better forest reserve. The rest of that day was than Augustin Stanciu, Romsilva 's Chi ef spent exa1nining oak tree after oak Inspector there. tree, with Augustin bursting forth with In the sutnn1er of 1995, my wife Edi e inforn1ation in Ron1anian and Stelian and 1 visited the Bejan Forest w ith doing his best to keep up in translation. Augustin, Dr. lng. Stelian Radu, and for­ In all, we saw e ig ht di ffe rent est guard D Lnn itru Pirlia. T he trip native oak species, and hybrids of 1nost began with an all-day ride of thetn, in this ren1arkable forest fron1 the airport of Bucharest north area of less than o ne square mi I e . through Ploiesti to Brasov, then west We knew at the titne that Augustin past Risnov and Bran, the fan1ou s home was not well. Erika to ld us in a letter the of the legendary Vlad Dracula. We following March that he was even using passed through the ancient citi es of extract from yucca plants to attetnpt a S ibiu and Sebes, tucked into the cure. But with the helpfu l oversight of Carpathian Mountains of Transylvania, his two supervising professors, then turned north for a slight detour Victor Stanescu and N icolae Sofl etea, he through hi storic Alba Julia. That night con1pleted his di ssertation before he we found ourselves in Deva, at the hotne died. It was accepted in 1997 by the of Steli an and Anette Radu. During the Ministerullnvatatnantului at Brasov in next few days we took sightseeing trips fulfilhnent of his degree. to the MedievaJ citadels of Hunedoara Augustin and Erika had presented one and Deva, the 1000-year-o ld church at of the original copies to n1e, together Hateg, and t he Roman ruins of with a rough translation, and it is sum­ Sarmizegetusa. We also botanized in marized here in Eng li sh. We are Retezat National Reserve and at the Na­ honored to share it with you now, both tional Arboretu1n at Sin1eria, for which for its valuable insights into oak Dr. Radu served as Director. hybridization and as a posthLnnous trib­ But then we saw something that eas­ ute to the enthusiastn, knowledge, and il y was the equal of all of these other perseverance of Dr. Augustin Stanciu.

Page 4 No.ll/ Fall 2000 International Oaks

by Dr. Augustin Stanciu Advisors: Profs. Victor Stanescu and Nicolae Sofletea

he Bejan Forest located near Deva in the Western Transylvania Region of Romania, has been well known since the last century as a unique ecological reserve sup­ porting nurnerous hybrids of indigenous oaks. The literature cites the fo ll owing oak hybrids in the Bejan Forest: • Q. Xtabajdiana Simonk. (Q. .frainetto x Q. po/yca1pa) • Q. Xh(j'ae Simonk. (Q.frainetto X Q. petraea) • Q. xdacica Borb. (Q. polyca1pa x Q.jJubescens) • Q. xhaynaldiana Simonk. (Q. .frainetto X Q. robur) • Q. xkerneri Simonk. (Q. pubescens x Q. robur) • Q. xbudensis Borb. (Q. pubescen · x Q. virgiliana) In addition, some varieties of these hybrids are also n1entioned: • Q. xdacica var. tiszae Sin1onk. et fekete • Q. xhaynaldiana var. hez?f!elii Simonk. • Q. xkerneri var. devens is (S in1 onk.) Otu· investigations, petfon11ed in 1988 1989 and 1990 revealed a series of new hybrids and varieties not previously recorded in the Bejan Forest. This is not surprising, since no less than eight of the nine indigenous oak tree species of Romania occur in an area coverin g only 200 ha, providing many opportunities for intetfettilization. The newly identified taxa are: Q. xrosacea Besch st. (Q. robur x Q. jJetrea) Q. xrosacea var. petrae[jor1nis Beldie. Q. xrosacea var ..f eketei Simonk. Q. Xrosacea var.jahnii Sin1onk.

contd. on pg. 6

No .11 I Fall 2000 Page 5 International Oaks

• • • contd . from pg. 5

Q.xpseudoda/echan1pii Ctrtz. (Q.rohur x Q. da!echan1pii) Q. xpseudodalechampii var. cretzoui CT\ L ~ Pascovschi .0 c L ~ Q.xcsatoi Borb.(Q.robur X Q. +­ \/) polycarpa) ..s:: ·+-- "0 Q. xdiverstfrons Borb. (Q. petrea X Q. w o(5 >­ virgiliana)) ::J ~ Q.xcazanensis Pascovschi (Q. :J) dalechan1pii x Q. virgi/iana) Q. xturae (Q. frain etto x Q. petraea) in the Bejan The differences between these new Forest near Deva. Romania (tree #695-5). hybrids have been established, in gen­ conclusion is reinforced by the observa­ eral, using the diagnostic criteria in Flora tion that there is a consistent Jnorpho­ Romaniei (Flora RSR) and Monografia logical stability an1ong these hybrids. Stejarilor din Ron1ania. For hybrids be­ Thus, the following hybrids have been tween the Ses sil~flora e Series and Q. provision a] ly described: virgiliana, the diagnoses are original. For • Q. petraea X Q. dalechan1pii instance, in Q. xdiversifrons, leaves are • Q. petraea X Q. polycarpa intermediate between the two parent spe­ • Q. dalechan1pii X Q. polycarpa cies, but closer to Q. petraea (not having alternate characters). The shape of cup The characteristics of the leaves of scales also shows traits of Q. petraea, in these hybrids are i ntennediate between addition to Q. virgiliana: short peduncles those of the parent trees (leaf shape, lo­ (0.5-0.8 cn1) and no sessile cups. bation, forn1, etc.), or closely resemble one Since oak species such as Q. petraea, of thetn (co ri aceousness and shin iness), Q. dalechan1pii and Q. pozycarpa are in the same case being true with fru its (cups direct contact in the Forest, but the For­ partially flat and partially globular). How­ est itself is somewhat isolated, we believe ever, for all of these hybrids, diagnoses the hybrids we have investigated are true are provisional and should be supple­ hybrids and not subspecies or vari eties, mented by subsequent investigations of as sometitnes has been proposed. This n1aterial derived fron1 other trees.

Pa e 6 No.ll/ Fall 2000 International Oaks

A special place in the study of Bejan Q. xdacica var. tiszae Simonk. et Fekete Forest is occupied by hybrids resulting (Q. polycarpa X Q. pubescens) from repeated backcrossing, and the Q. xszechenyana Borb. (Q.frainetto x Q. double or multiple hybrids confirm the pubescens), cited by A. Savulescu (un­ very remarkable ability to hybridize within published). tnixed populations of local oak trees. This has produced the hybrids between Q. Another problen1 resulting from the petraea and Q. xrosacea, between Q. hybridization of oak trees in the Bejan xtufae and Q ..frainetto (introgressive ), and Forest involves the con1binations with between Q. p etraea and Q. genitors from the Lanuginosae Series (Q. xpseudodalechampii (multiple hybrids). pubescens and Q. virgiliana). Since these There are, no doubt, other series of sec­ species possess a broad polyn1orphism, ondary hybrids in the Bejan Forest. Fig­ some uncertainty is introduced in the di­ ure 1 is a diagrammatic rep­ agnoses of Q. xdacica, Q. resentation of all known xszchnyana, Q. hybrids in the Forest. xcazanensis, Q. xkerneri Nevertheless, we have (Q. pubescens x Q. to mention that in our field p etraea), and Q. research and in the mate­ xkanitziana. rial previously collected (leaves and fruits har­ Genetic Prospects of Oak vested by Augustin Hybrid Populations Stanciu, working under From data collected in the auspices ofRo1nsilva's the field and from the lit­ Forest District Inspec­ erature, we have con­ torate for Hunedoara), we cluded that among the vari­ failed to find the following ous indigenous oak tree hybrids previously cited in ©Guy & Edith Sternberg species in the Bejan Forest, the Bejan Forest: Q. polycarpa x Q. dalechampi i in except for Q. cerris, there Q. xtabajdiana Sitnonk. the B~jan Forest near Deva. probably is full genetic Romania (tree #695- 13). (Q. frain etto x Q. compatibility for hybridiza­ polycarpa) tion. Therefore, we also expect to iden­ Q. xhaynaldiana Simonk. (Q. .frain etto X tify other hybrids in addition to those de­ Q.robur) scribed in the I i terature, or those de­ Q. xhaynaldiana var. heuffelii Sin1onk. scribed previously by us. In fact, we can Q. xkerneri Simonk. (Q. frainetto X Q. speak of a series of oak hybrids, within polycarpa) Q. xkerneri var.devensis Simonk . contd. on pg . 8

•

, No.ll I Fall 2000 Page 7 · International Oaks

• • •

contd. from pg. 7

which various forms can be distin­ be distinguished in oak trees: • gui shed, son1e being closer to one or the Dominance: Manifest in typical or other genitor. nearly typical characters of one of the The hybridization phenomenon in oak two genitors in descendants. This is the ' trees in the Bejan Forest is also compli­ case with the shape of the Q. robur oak cated by the possibility of introgression leaf in the hybrid Q. xrosacea: with the and double or multiple hybridizations. This base of the oak leaf in the same hybrid; is the case already mentioned for the hy­ with the hairiness of leaves and stems brid between Q. xpseudodalechan1JJii and of1nost hybrids having Q. pubescens or Q. petraea. However, it should not be con­ Q. virgiliana as one parent; and with cluded from these results that there are coriaceousness and shininess of the up­ not litnits to intetfettilization in the Forest. per surface of leaves in hybrids with Q.

• Our data show that hybrids congregate jJolycarpa as a parent. around their genitors; thus, true Sen1i-Dominance: Represented by in­ interfertilization circles can be di stin­ tennediate characters between the genitors. gui shed, circumscribed by the reduced Examples are Q. xro ·aea var. cretzoui and distances that tllost pollen granules move. Q. xcsatoi, with pedunculate, shott acorns, However, the actual dimensions of these characters intern1ediate between sessile­ intetfertilization circles need further inves­ flowered and pedunculate oaks. Semi-dotlli­ tigation. nance is also present in Q. xdacica and Q. In this sense, it would be helpful to xdacica var. tizsae as leaf and stem pubes­ detennine the ecological component in cence up to disperse pubescent al­ the process of natural selection of hy­ though in other cases, pilosity remains a brids of various orders. The study of hy­ don1 inant character.

brid oak populations in the Bejan Forest Co-Dominance: Having characters of • offers valuable data on establishing rela­ both genitors in the san1e organ, such as tionships between genes in descendants hybrid leaves resetnbling those of one as related to genitors, as well as in rela­ genitor, Q. petraea in the upper distal ' tion to the nature of genetic control over part, and resetnbling the other genitor, Q. sotne characters. Thus, by extrapolating dalechampii, in the basal patt; or as in reJationships between allele genes frotn the Q. xcazanensis hybrid, with Q. intraspecific hybrids to interspecific ones, virgiliana scales in the upper part of the the following types of relationships can cup (flat Ian ceo late) and Q. dalechamJJii

Page 8 No.ll/ Fall 2000 International Oaks scales (tuberculate) in the lower patt. leaf shape and lobation, on one hand· and Alternate Co-Dominance: Revealed by shape and lobation of leaf versus gla­ the appearance, rather frequent in oak brous character or pilosity of leaf surface hybrids, of characters of both genitors in on the other hand. This means that the the satn e organ , but on different controlling genes of these characters are branches as in Q. xrosacea var jahnii, located either at large distances on the Q. Xtufae) etc. satne chron1osome, reducing the likeli­ hood of linkage, or are located on differ­ Linkage ent chromosomes. The genetic control of characters ap­ In other situations, characters tend to pears independent for characters such as contd. on pg. 10

a. pedunculiflora ""-'.------~a. petraea

• • I . • ' • I • . . . . I I ' \ \ - . . I . l \ ' a. robur . . . pse~dodalechamp ii .. ' . a. dalechampii ~~~. . - . . - . . Cretzoiui I • I ' -4 \ . . ~ \ I • ,. I I ~ . . \ · . 9salo; 1 '\ - ~ • . . . Lupe1 · .... / · \ I • tP · devensis' I • ..._ I • • ~\ • I '& ' . . q \ ' '.-;.. I ~%·,., • .· .uI '11 . ' Heuffeli I ~ • . • • • • • ' ~ -~ • '~ . c: ) " • 0) ~ I (\'\ . •:;) ;:..,. I ...... '~ ~ I I <:- ' a> () It . -? /~ .~ dobrogensis -- I ' ~ I - I I ' I ' a. pubescens a. frainetto

a. V1rgiliana

Fig. 1 - Diagram of Quercus genus hybrids (after C. C. Georgescu and I. Moraru) with data added from Flora Romaniei and our own investigations in the Bejan Forest)

LEGEND: Hybrids in flora of our country mentioned in ,.Monografia stejarilor din Romania". -----·-· -· Hybrids occurring in the Bejan Forest. after .. Flora Romaniei" -··-· ·- New hybrids in the Bejan Forest (already desaibed in literature) -···-... New hybrids in the Romania's flora (for science?) identified in the Bejan Forest ••••••••••• Multiple hybrid and introgressive hybrids identified in the Bejan Forest

No.ll I Fall 2000 Page 9 International Oaks

• • • contd. from pg. 9 be trans1nitted in association, such as leaf Forest, of course, is not just a recent phe­ ' shape with lobation, lobation with length notnenon. It is possible that hybrids of of petiole, coriacity and shininess with various orders appeared at different leaf pilosity and shape of scales of cups, titnes, with natural selection preserving etc. These characters could be controlled the 1nost balanced heterozygotes. by linkage or even by supergenes. The hybrid populations in the Bejan However, linkage or crossing-over rela­ Forest offer an opportunity to establish tions are hidden in hybrids by the presence the relationships between the allele genes of genes derived from both parents, so that fro1n descendants ( do1ninance, semi­ in these instances, the use of some direct dominance, co-dominance, alternate co­ 1nethods of investigation are required. dominance). However, this study of Quercus hybrids does not offer sufficient Conclusions conclusive data on the linkage and cross­ Oak hybridization in the Bejan Forest, ing-over relationships, hidden in hybrids which is almost devoid of genetic inter­ by the relationships between the allele specific constraints, is a ren1arkable phe­ genes derived from the two genitors. But nomenon. Further studies are needed the valuable gennplas1n existing in the fro1n taxono1nic, ecological, physiologi­ Bejan Forest de1nands the establishtnent cal, and of course, genetic standpoints. of special ecological and genetic preser­ The ecological circun1stances allowing vation and conservation strategies. New interfertilizati on of oaks in the Bej an For­ investigations on local vegetation and est need particular attention. Neverthe­ biotypes should also be undettaken. less, due to the frequency of local intro­ gression, one can conclude that the hy­ References Cited in this Synopsis brids are fertile, at least partially. Georgescu, C. C., and I. Morariu, 1944. • Besides the phytogeographical influ­ Monogrq{ia Stejarilor din Ro1nania, ence of species interaction, phenological ICES, seria 11, Bucharest, Ro1nania differences exist. They are related to titn­ ing of growth initiation, flowering, po11en ***, 1952. Flora RSR, vol. I, Ed. Acad­ production, and fertilization and could emy ofBucharest also affect hybridization. These should be investigated fu1ther. (Note: 90 additional citations are listed Hybridization of oak trees in the Bejan in the original dissertation) International Oaks

byFredLape former Director, Landis Arboretum

The following article is taken .lrom the Landis Arboretutn Newsletter covering April, May, and June of 1982. In it, Fred Lape, who passed away in 1985, describes a huge oak, called the .. Big Oak" that, at that time, was designated the official Logo o.f the Landis Arboretum by the Board o.f Trustees. It re­ mains the Logo to this day, but is now called the "Great Oak. " The George Landis Arboretum is located on a hillside above the village o.f Esperance, Nevv York, and overlooks the Schoharie River Valley. Its 97 acres are ho1ne to more than 2, 000 species o.f trees, shrubs and herbaceous plants. The Ar­ boretum de1nonstrates the unity and diversity oj'plant life through its living collections and educational progran1ming.

he Big Oak of the Landis Arboretu1n is an Eastern White Oak (Quercus alba). The species ranges from Maine to Georgia, but flourishes best in the section from southern Connecticut and Long Island through easten1 Pennsylvania where it is often the dominanttree.lt is not co1nn1on in New York State north of the Mohawk Valley. The Big Oak n1ust have been an outstanding forest tree when the land, nuw the Arboretu1n, was cleared about 1840, for it was singled out by the first owner to be left standing in the open. My first men1ory of the tree dates frotn about 1910, when I was get­ ting old enough to pay attention to trees. It seetns to me now in men1ory that its trunk was as large then as it is now, but early life tne1nories usually tnagnify with time. There were already two lightning scars, which wriggled like gigantic snakes down the

contd. on pg. 12

No.11 I Fall 2000 Page 11 International Oaks

• • • contd. from pg. 11

east and south faces of the trunk; the I have never lived through a tnajor earth­ traces of which sti ll remain. quake nor a tornado or hurricane. The last It was probably one of the feature of night ofthe ice storm was the greatest natu­ f the farn1 that induced my father to buy ral disaster I have ever experienced. Few the property for he loved far views. lle persons on these hills slept that night. itnn1ediately nan1ed the place Oak Nose Fron1 late afternoon of the third day when Farn1, and always took visitors to see the large litnbs of trees began to give way the views up and down the Schoharie and all through then ight to the next tnotn­ Valley, which one gets fron1 the knoll ing, there was a constant bornbardment upon which the oak stands. The knoll fron1 the crashing of J imbs as they broke itself is part of a glacial moraine that was loose fro111 trees and fell. dutnped across the valley during the last On the fourth n1oming the storn1 had glacial retreat. ended and the sun can1e out. I walked over We have never taken borings of the toward the Big Oak to see the datnage. On tree here at the Arboretum to a certain the way up to the knoll one looks over a its age. Fron1 cotnparing the size of the section of the wood-lot that had always trunk and branch spread with that of been the sap bush., with large tnaple trees certain fatnous oaks in southern New that had furnished sap for maple syrup for England and on Long Island, whose ages a hundred years. There was not a single are roughly known from certain histori­ large 111aple left standing, only the stripped cal events which happened near or un­ tops of trunks and the tnass of fallen der then1 we guess the Big Oak to be branches glistening in the sun. The Big fro111 350 to 500 years old . Oak lost al1 of its branches on the north­ It was a flourishing tree until 1940. east side, about half of its crown.

Then a natural disaster overtook it. That [fat the ti1ne 1 had either the n1oney or • year there was an ice storn1. ft rained the experience to repair the dan1age after stcadi ly and heavily day and night for the stonn the tree could probably have three days the rain freezing as it fell. By recovered co1npletely for it was then a • the end of the storrn, every blade of dead vigorously growing tree. r had neither and grass in the fields was coated with solid did nothing. So in a few years the open ice to the thickness of a n1an 's thun1b, wounds left along the trunk by the pu Iled and all the branchlets of trees were out bases of the falling lin1bs began to rot equally coated. inward. Once water was able to reach be- International Oaks yond the growing layer of the wood, the to grow vigorously. But during the last rotting inward and down accelerated, and four years, large lower branches have bro­ has continued ever since. Coons began ken off without even a high wind or a to nest inside the hollow trunk. heavy snow to cause the break; merely In the 1neantime the tree has continued the weight of the branches overpower­ ing the now shallow moorings which they have in the trunk. Whether anything could be done now that is worth doing is doubtful. The very lower section of the tn1nk still see1ns solid, but the upper section is completely hollow, and one can look up frotn the lower holes to light in the upper ones. Even as it stands, the tree may live another hundred years, for the wmte oak is a vigorous species. However, the clitnax of its life definitely carne at the end of three days offreezing rain in the winter of 1940, and from then on its way has been downward.

Thanks to arborist Fred Breglia of the Landis Arboretum.forjitnishing this story and photograph. Fred reports that the tree is still strong, n1.ore than a halfcen­ tury after the big ice storm.

Reprinted with per­ Tn iss ion, Landis Arboretu1n Newsletter, May-June, 1982.

photo by Fred Breglia The Great Oak in Landis Arboretum.

No.ll I Fall 2000 . Page 13 international Oaks

by Jennifer Juzwik Research Plant Pathologist USDA Forest Service, North Central Research Station St. Paul, Minnesota, USA

ak wnt, caused by the fungus Ceratocystis .fagacearuntz (Bretz) Hunt, is an in1portant disease of oaks (Quercus spp.) in the eastern United States. The disease occurs in 22 states and is considered the tnost in1portant forest disease problem in Illinois, Iowa, Minnesota, Texas and Wisconsin. The pathogen causes tnortality of thousands of native oaks annually in urban and natural forests in the not1h-central United States and in Texas. Over 33 species and varieties of Quercus are known to be sus­ ceptible to C. _[agacearun1. In addition, three species of Castanea, one species of Castanopsis, and one species of Lithocarpus are also susceptible. Within the subgenus Quercus, members of the section Erythrobalanus (== section Lobatae) (the red oak group) are very susceptible while rnembers of the section Quercus (the white oak group) range from quite susceptible to highly resistant. Oaks are a don1inant component of the expansive oak-hickory forests of the central USA that prevai 1 from the not1hern boreal forest region to the states bordering the Gulf of Mexico. The oak species group is the 1nost important aggregation of hardwoods in the United States. In the US, oaks are itnportant for providing food for birds and mamn1als, wood for lumber and veneer, cooperage for the beverage industry, and as landscape trees. Oak wilt was officially identified and the causal fungus was described in the early 1940s. However, accounts of sirnilar oak problen1s suggest the occurrence of the disease as early as the mid- to late 1800 's in Minnesota and Wisconsin. The disease is International Oa/(s now known to occur within the area de­ vidual leaves wilt frorn leaf tip and tnar­ lineated from Minnesota east to Pennsyl­ gins to the ba ses, turning bronze to vania, south to South Carolina and Ten­ brown. Fallen leaves are often green at nessee, west to notihern Arkansas and the base. In contrast with the red oak eastern Oklaho1na, and north through group, infected white oaks usually die eastern Kansas and Nebraska to Minne­ slowly, a branch at a titne, often surviv­ sota. A sign ificant southern extension of ing for many years. Leaf discoloration of the oak wilt range was recognized in the affected white oaks resen1bles autun1n early 1980s when the disease was con­ colors. Affected live oak leaves in Texas finned in nottheastern and central Texas exh ibi t inter-veinal ye llowing and brown­ where it has since becon1e increasingly ing during late spring and sutnn1er. In spe­ important. cies of both the red and white oak group the outer ring of springwood vessels will Symptoms be plugged with brown material (tyloses Oak wilt is easily identified in members and gun1s) and streaks of brown tnay be of the red oak group by the rapid wilting obvious on the outside of the wood. The ofaffected trees. After SYJnpton1S first ap­ vascular discoloration is n1ost easily seen pear, a red oak n1ay wilt completely within four to six weeks. The trees wilt from the top of the crown downward and indi- contd. on pg. 16

• US Couqties with Oak Wilt - 1999

---·------'

No.ll I Fall 2000 Page 15 International Oaks

• • • contd. f rom pg. 15 in cross sections of infected branches of Above ground spread of oak wilt is ac­ • white oaks, and less readily observed in complished by insect vectors which have infected red oak branches. acquired viable spores of the oak wil t fun­ gus. The fungus spores are then trans­ • Disease Development and Spread mitted to healthy oaks. Insect transtnis­ The causal fungus reaches healthy sion is sign ificant in the establishment of oaks through roots grafted between di s­ nevv infection centers in adjacent as well eased and healthy trees or via insect vec­ as distant forest stands, and is the only tors that carry spores of the fung us on way the fungus can cross hi ghways, riv­ their bodies. Once introduced, the Jnyce­ er~, and open fi el ds. In the Upper Mid­ lium of the fungus grows into the water­ west in the US, sap beetles of the insect conducting cells of the xylem. Second­ fa tni ly N itidulidae are considered the pri- ary invasion of the ray cells may follow. 1na1y vectors of C. jagacearun1. ln other The fungus physically plugs the ce ll s parts of the oak wi lt range, oak bark of the xylem as do tyloses fom1ed by the beetles (PseudopityO}Jthorus spp.) and tree in response to fungal invasion. This an1brosia beetles have been in1plicated as plugging prevents the upward transloca­ in1portant vectors of the causal fungus, tion of water and tninerals to the fol iage, although the relative in1portance of each resulting in wilting of the leaves. In the insect vector group is not known in these spring or fall in1tnediately following tree areas. Two species of sap beetles death, the fungus aggregates on th e in­ ( Carpophilus sayi and ColoJJferus ner pbloe1n and outer xy lern of the trees truncatus) have recently been identified forming tnirror-in1age structures known as as the principal insects involved in suc­ oak wilt tnats. Mats may fonn on in this cessful trans1nission of C. .fagacea rLI/11 to tnanner on n1ain stetns and branches that healthy trees in Minnesota. Sap beetles over 6cm in dian1eter. Spores of the fun­ are com n1 only attracted to the sporulat­ gus are produced on the mats. Special­ ing mats produced between April and

ized con1pact ti ssue called pressure pads earl y July on red oaks that wilted the pre­ • a Iso form with in each tnat. Pressure ex­ vious sun1mer. This is also the satne pe­ erted by the growing, opposing pads of­ riod of tin1e during which red oaks pro- ten forces open the bark, causing a velii­ cal crack through which insects tnay en­ ter. contd . on pg. 18

Page 16 No.ll/ Fall 2000 International Oaks

Nitidulids visit fresh wounds on healthy oak ..-.. and deposit spores . 0 ~s.. ,.,.~ Spores A c germinate ~ Nitidulids feed in infect oak K c pads and emerge • ·.8 with spores in and ~ on their bodies. ~ w ·-c I L T

Infection spreads D '"0 throughout the tree C':S and leaf symptoms ~ develop. I E,. Fungal pressure 00 pads and spore­ s ""0 bearing mats form ; under bark. E ~ s.. ~ A ~ s 0 ---- I ops1n E ---' vascular tissue. .--. s..r.l1 c ....~ dies. =~ '"0 CJ y ~ ~ s.. =Q spores move through c.·.c :ea roots into adjacent c 00 CJ uninfected trees. c:t": ~ L ~s.. ·-= ~ ...Q Healthy E ..... trees 0 =Q 0 become ·-r.l1 infected. ~ = =c.. ~ ~.._,

drawing courtesy of United States Department of Agriculture Forest Service, Northeastern Area, State and Private Forestry

No.ll I Fall 2000 Page 17 International Oaks

••• contd. from pg. 16 duce large springwood vessels and thus roots in existing infection centers is an are particularly susceptible to infection. in1portant pa11 of an oak wilt control pro­ Several species of the same sap beetles grain. Disruption of root grafts can be ac­ are also attracted to fresh (general1y less complished mechanically using a vibra­ than 48 hours old) wounds on healthy tory plow with a 1.5 tn (5-foot) blade, or oaks during spring (e.g. from early Apri 1 with a trenching machine that reaches to early July in Minnesota). Visitation of depths of 1.2 m (4 feet) or greater. If buried such wounds by C.fagacearum-containi­ utilities are present, manually dug nated beetles results in oal< wilt infection. trenches or a chemical soi 1 sterilant Once a tree in an otherwise oak wi It­ (Vapan1) can be used to disrupt roots, but free stand becotnes infected via insect neither is nearly as effective as the lne­ transmission, the fungus moves to adja­ chanicaltnethods. Root graft barrier 1ine s cent trees through grafted roots. This is tnust be positioned between oak wilt in­ the means by which the highest propor­ fected and non-infected trees. Often, two tion of oaks becomes infected. Grafting lines are recomn1ended: a primary line out­ between trees within a Quercus species side a ring of apparently healthy trees that tnay be cotnmon, but frequency is influ­ tnay actually have early infections, and a enced by distance between trees, pres­ secondary barrier outside of every obvi­ ence of other species, soil type, and to­ ously infected tree. The fungus can be in pography. In Texas, live oaks in a stand a tree for 2 - 3 weeks without leaf synlp­ are generally all inter-connected via a cotn­ toms appearing. Barrier placetnent re­ tnon root system due to the sucker-repro­ quires experience and requirements vary duction habit of the species. Occasion­ by reg-ion. In the Upper Peninsula of ally root grafts may occur between differ­ Michigan, a model based on tree size and ent species of oaks. Outward spread of two soi I types has been developed to the fungus via root grafts from the ini­ place lines such that they have 95 per­ tially infected tree often leads to itTegular cent and 99 percent probability of pre­ circular patches of dead and dying trees venting root graft transmission (sumtna­ called infection centers. rized in Cutnmings-Carlson and Martin, 1994 ). The oldest model for the region (as Disease Management in French and J uzwik, 1999) has been Stopping spread of C . .fagacearutn shown to be 85 percent to 93 percent ef­ through con1mon root systen1s or grafted fective when experienced arborists place

Page 18 No.ll/ Fall 2000 International Oa/(s

lines. In Texas, root graft barriers are es­ ment of infected trees in early stages of tablished 30 Jn beyond the last infected wilting. Girdling trees into the outer xy­ tree and the remaining living oaks be­ lem weakens the standing tree making it tween the infection center and the barrier 1nore susceptible to toppling by wjnd. are rogued. Herbicide treatlnent of living Liability issues prevent the use of this oaks surrounding infected trees is a n1ethod in residential settings. Infected I method currently being investigated as white oak (Q. alba) do not need to be an alten1ative to mechanical disruption removed because the fungus rarely methods where topography location etc., sporulates on this species. may prevent their use. In high value white Oaks should not be wounded or pruned (subgenus Quercus) and live oaks sys­ during the critical spring 111onths (e.g. temic injection with propiconazole by a April through June in Minnesota) or warm qualified arborist may prevent infection winter and spring months (e.g. Novem­ of trees adjacent to oak wilt infected ones. ber through April in Texas) when the sap Preliminary data also suggests that beetles are active and oak wiJt mats are high value red oaks (subgenus Lobatae) present. Tftrees are accidentally wounded 111 a y a Iso be s i n1 i 1a r 1y protected . or pruning is unavoidable during these Propiconazole treatment of white oaks high susceptibility periods, the wounds exhibiting early crown symptoms of oak should be imtnediately painted with wa­ wilt (i. e. theraputic treattnent) can also ter-based paint or she llac to prevent di­ prevent further disease development rect contact of the beetles to exposed within infected trees for at least two years wood. Tree clitn bing irons should never in species of this subgenus. be used on living oak trees. Aboveground transmission of the oak Oak wilt 1nats tnay form on logs cut from wilt fungus is less readily controlled than wilting or recently wi lted trees and should belowground spread. Current efforts in not be 1noved in any fonn (including frre­ established control programs include the wood) to areas where oak wilt is not rernoval of recently killed red oaks prior present. Oak wilt mats n1ay fonn on these to formation of oak wilt mats in the spring. logs. Long distance movement of fire­ In Minnesota and Wisconsin, for ex­ wood obtained frotn such logs has ac­ ample, such trees should be retnoved and counted fo r the establishment of oak wilt properly disposed of or treated prior to centers in areas of Michigan, Minnesota, April. In forest stands where a large nutn­ and Texas that previously had been un­ ber of trees rnay be involved or where affected by the disease. European coun­ location prohibits tree retnoval, n1at for­ tties require chemical futnigation (e.g. with mation can be li1nited or prevented by gir­ tnethyl bron1ide) of oak logs before im- dling the infected oaks as they begin to wilt. Successful use of this tnethod re­ quires early disease detection and treat- contd. on pg. 20 International Oaks •

• • • contd. from pg . 19

portation from counties in the USA with Minnesota Extension Service, MT-3174- known oak wilt infection centers. Z. 6 p. Gibbs, J.N., and French, D.W. 1980. The Selected References trans1nission ofoak wilt. USDA For. Serv. Appel, D.N. 1995. The oak wilt enig1na: Res. Pap. NC-185. Perspectives .from the Texas epidemic. Tainter, F.H., and Baker, F.A. 1996. Annu. Rev. Phtyopathology 33:103-11 8. Principles of Forest Pathology. John Cumn1ings-Carson, J. , and ~Martin , A.J. Wiley and Sons, Inc., New York, NY, USA. 1994. Lake States Woodlands: Oak wilt USDA Forest Service. 2000. U.S. n1anagernent What are the options? counties with oak wi It - 1999. University of Wi sconsin, Extension Northeastern Area State and Private Publication G3590, Madison. 6 pages. Forestry - St. Paul Field Office website French, D.W., and Juzwik, J. 1999. Oak (http://wi llow.ncfes. u1nn .edu/oakwilt/ wilt in Minnesota. University of dist_ sn1 . htrn)

Editors Note: As this issue of In­ when the fungus penetrates the bark ternational Oaks was going to press, and begins to kill the tree's phloem. Professor Juzwik contacted us with David Rizzo,,a plant pathologist at some news about the Sudden Oak the University of California at Davis, Death (SOD) disease that has been identified the pathogen as a new killing oaks in California. ·Suspected Phytophthora species which does not . by some to be a variant of Oak Wilt, match any of the 60 known new research results have found in­ Phytophthora species anywhere else stead that the problem apparently is in the world. It can be spread in soil caused by an as-yet unidentified spe­ (on shoes, tires, etc.) or in infected cies of the Phytophthora genus of wood. fungi. For more information on SOD, refer The epidemic affecting tanoaks, to the fo11owing web site: coast live oaks, and California black http://camfer.cnr. berkeley.edu/oaks/ oaks was frrst noticed in Mill Valley, and review the other infon11ation avail­ California in 1995. Thousands of trees able through:;.theliriks page of the In­ in the area from Santa Barbara to ternational Oak Society web site: Humboldt counties have beco1ne in­ http://www. saintn1arys. edu/--rj ensen/ fected. Trees ooze a dark, viscous fluid wwwsites.httnl

Page 20 No.ll/ Fall 200@ International Oaks

by Michael Martin Melendrez Los Lunas, New Mexico

resented below are 23 species of white oak, six of black • oak, and two intermediate or golden oaks, found in the southwestern United States (primarily New Mexico, Ari­ zona, and western Texas). These nutnbers tnay be disputed by some oaks students. Differences of opinion exist as to the true boundaries of the Chihuahuan Desert the potential hybrid sta­ tus of sotne of the oaks, and their delineation. Also new oaks not previously known to occur in the area are continually dis­ covered. Counting the additional oaks found in the adjacent Mexican State of Chihuahua, there are n1ore than 60 species. The Chihuahuan Desert Region is truly The Land o.fOaks. The production nursery industry of our area has started, on a small scale, the introduction of oaks with a limited species selec­ tion. Unfortunately the southern live oak (Quercus virginiana) usually is the first one to be grown and sold, and it is commonly promoted as the best oak for the desert cit­ ies of the Southwest. The species of oak na­ < Guy & Edith Sternberg tive to this arid part of Author ,\1/ichae/ i\1/elendrez standing below Q. ari zonica the country are 1nuch in Catwalk Can• l'0 /1, Gila National Forest. New Mexico. contd. on pg. 22 International Gales

• • • contd. from pg. 21

better adapted here, and thus tnake bet­ ter choices for shade trees than the southern live oak. • At our nursery production progran1 in Los Lunas, New Mexico, at 4,900 feet el­ evation and USDA Zone 6b, the native oaks outperform the southern live oak in speed of growth, heat tolerance in a con­ tainer, and over-wintering success. In fact, we are unable to winter the south- • ©Guy & Edith Sternberg ern 1ive oak outdoors, but with the na- Acorns ofQ. arizonica collected at elevation 5,200 tive oaks we can. We also 1nust be aware ft. along the Gi!a River in New Mexico. of potential problems with live oaks (and red oaks) that have been harvested or 1. Q. arizonica -Arizona white oak collected from areas of Texas where oak Description: A medium-sized tree of wilt has been found, as well as the po­ the southwestern United States and ad­ tential danger of spreading fire ants. jacent Mexico, 30 to 60 feet or more in The following introduction to the oaks height, and 2 to 3 feet in trunk diameter, of the Chihuahuan Desert Region of the with irregular spreading crown of stout United States is intended to illustrate the branches. Leaves obovate or oblong, 1- vast diversity of our native oak resource. 3 inches long, short-pointed or rounded at apex, heart-shaped or rounded at base, White Oaks Section Quercus (for- edges slightly wavy-lobed and toothed merly Lepidobalanus) toward apex, thick and stiff, above dull This group displays bark that typically blue-green and nearly hairless and with is light gray and scaly (but black and veins sunken, beneath paler and densely furrowed in escarpment live oak). Tyloses hairy and with prominent raised veins,

are present in sutnmer wood (absent in shedding gradually in spring as the new I escarp1nent live oak), and lobes of leaves leaves unfold, except in colder parts of are rounded, except for Q. turbinella and its range where it will defoliate in the late Q. hinckleyi (which both have sharp, fall or early winter. Often, in colder cli­ 1nucronate lobes) and Q. pung ens var. mates, they will display good fall colors vaseyana (with ahnost bristly tips). resembling burgundy wine. Aco1ns are

Page 22 No.ll/ Fall 2000 International Oaks

3/4 to I inch long, with shallow cups, mild to sweet nut-like flavor, particularly 3. Q. chihuahuens is - Chihuahua white in those found on the east slopes of the oak Organ Mountains. A tree to 40 feet tall with tardily de­ Distribution: Common in Arizona and ciduous leaves, greatly variable. Re­ in southwestern New Mexico, grading ported as being in the Quitman Moun­ into gray oak in the south-central high­ tains. I' ve yet to find this species, so I'm lands of New Mexico and perhaps in unable to offer personal observations. Texas in the Franklin and Hueco Moun­ tains. In the Manzano and Sandia Moun­ 4. Q. depressipes- Mexican dwarf oak tains this species is tnixed with gray oak An evergreen shrub to 10 feet, found and scn1b live oak, which can be quite in high grasslands or montane chapar­ confusing, with possible hybrid swanns. ral. It is found in the United States at the The habitat is oak woodlands in foot­ northwest sumn1it of Mt. Livern1.ore in hills and mountains from 5 000 to 7,600 the Davis Mountains of the Trans-Pecos feet elevation. Often this species is listed Region of Texas. as the largest of the southwestern ever­ green-type oaks, but this is not true, be­ 5. Q. fendleri (Q. xfendleri?) - Fendler cause En1ory oak becotnes a larger tree. oak Also called Capitan blue oak. 2. Q. carmenensis- Delcannen oak Description: Some students of oaks Recently reported in the Chisos Moun­ will lump this oak into the undulata hy­ tajns by Professor Mike Powell of Al­ brid group without n1uch thought given pine, Texas, who found only one speci­ to the gross n1orphological differences men about 3 feet tall. Cornelius Muller between the two. Fendler oak is an ever­ considered this scrub oak a hybrid. green or tardily deciduous species with oblong, sharply lobed leaves that are a tnetallic blue green. Bark is smooth and gray on young trees, turning to nearly black and checkered with age. Distribution: Native elevation range is 5,500 to 6,000 feet near the Capitan Mountains of south-central New Mexico. Under cultivation, Fendler oak is rapid growing and very ornamental, able to grow well in high pH clays. Fendler oak ©Guy & Edith Sternberg Foliage ofQ. arizonica in Cave Creek Canyon, Coronado National Forest. Arizona. Elevation 5,500/t. contd. on pg. 24

No.ll I Fall 2000 Page 23 international Oaks

• • •

contd. from pg. 23

can grow into a 40 to 50 foot single-stetn wild with a crown spread of30 to 35 feet. tree, with no habit of suckering. Leaves lance-shaped, 2 to 3 inches long and 1/2 to I inch wide, with short, spiny 6. Q. .fitstforn?is- escarpn1ent live oak lobes on young, fast-growing trees. Fall Also called New Mexico live oak. color can occur on trees in colder cli­ Description: Evergreen to sen1i-ever­ tnates, and can continue as winter color. green small tree, usually to 25 feet in the Acorns are sn1all and tnuch like those of the Etnory oak, 1/2 to 1 inch long and narrow, fonning in clusters (southern live oak has a larger, bulb-shaped acorn borne singly or in pairs). Bark is dark gray on young, fast-growing trees, turn­ ing a rough black with age, as is typical ofn1any black oaks. Distribution: Not always distin­ guished frotn the southern live oak in the literature. Lacking the tyloses of ©Guy & Edith Sternberg other white oaks, this species sometitnes Q. fusiform is, a cultivated tree in Tulsa. is assigned to the black oak group. This Oklahoma. North of the natural range. di stinctive evergreen tree is perhaps tnost ecologically suitable for the high, cold desert. Provenances of greater cold tolerance can be found in eastern New Mexico (on the Caprock formation east

of Roswell at 4,000 feet elevation) in I Garza County, Texas (at 2,200 feet eleva­ tion), and in Greer County, Oklahon1a (in the Quartz Mountains). A cotnn1on fail­ , ure of growers in the Southwest is not being careful with the seed source ofthis 19Guy & Edith Sternberg species resulting in growing southern Q. fusiformis near Quartz Jvlountain, Oklahoma. live oak and calling it escarpn1ent live This is a/ the northernmost natural popuLation of the species . oak in error. If planted in the A lbuquer-

• International Oaks que (USDA Zone 7a) area, only the New Mountains oftheGilaNational Forest, it Mexico tnaterial will prove to be ever­ can be found as low as 4,700 feet, with green and dependable. large, healthy populations. It occurs froin the Mexican States of Chihuahua and 7. Q. gambelii- Garnbel oak Coahuila north to Colorado, west to Also called Utah white oak or Rocky southwestern Wyon1ing, Utah, and Mountain white oak. N atnes sometin1es southern Nevada. Gambel oak is the only considered as synonyms include Q. native oak of Colorado and is the only carmenensis, Q. confitsa, Q. gunnisonii, con1n1on tree oak in the northern parts Q. leptophy lla, Q. 1n edia, Q. of New Mexico (excluding the Sandia, novomexicana, Q. obtus ifolia, Q. Zuni and Manzano Mountains). An­ pauciloba, Q. rydberg iana, Q. other interesting note on this species is submollis, Q. undulata, Q. utahensis, Q. that it will occur at lower elevations in venustula, Q. vreelandii. the southern part of its range than it can Description: A decidu­ up in Colorado or Wyo­ ous tree to 60 feet in wild ming. Gatnbel oak is easily stands and 80 feet under recognized by the deeply cultivation. A rare compo­ lobed leaves, which are nent of the Madrean oak larger than those of the ev­ woodlands and more ergreen to se1ni -evergreen common in the Pine Tran­ Southwesten1 oaks. It is sitional and Mixed Coni­ quite polymorphic and ac­ fer zones. The largest cording to tnany authors trees are found at 8,000 is involved in the parent­ feet in the grassland parks age of many hybrids. of the Gila National For­ Some of the oaks with est of southwestern New which it crosses are Q. Mexico, with trees cotn­ arizonica, Q. grisea, Q. ©Guy & Edith Ster nberg monly 60-100 feet in size. h. avar d . t·L ·, Q. moh rzana· , Q. In Texas it occupies only InternationaL Oak Society members 1nuhle nbergii, and Q. .Michael Melendrez (left). Guy the highest altitudes. I've Ster nberg (center), and Tom turbinella. The resulting found it difficult to locate Burleson with a large Q. gambelii hybrid grex is called Q. in Texas, except in the at Iron Creek in the Mimbres Moun- xundulata - wavy leaf oak. tains of New Mex ico. Ele vation Guadalupe Mountains 6,800 ji. When we have attempted and a sn1all population in propagating the so-called the Franklin Mountains near El Paso. In wavy leaf oak, the progeny do not hold the Organ Mountains, near Las Cruces, true, which suggests the hybrid theory it is comtnon from 8,900 feet elevation on down to 5,700 feet. ln the Mogollon contd. on pg. 26

No.ll I Fall 2000 Page 25 International Oaks

• • • contd. f rom pg. 25

habit. and leaves that are so hairy that you coul d say they are fu rry. Others near Glenwood, New Mexico could eas­ ily be tnistaken fo r Q. oblongifolia. Jt is a con1n1on oak of the desert grasslands chaparral and oak woodland s of the Chihuahuan Desert, becotning less com­ tnon in the Transitional Pine Forest of central New Mexico at elevations above 8,400 feet. Gray oak can grow in a wide c•Guy & Edith Sternberg Foliage of Q. gambclii in Catwalk Canyon. Gila range of soil types, from heavy saline National Forest. Nell' /vlexico. clays to gravel or sand cond itions. It seems always to be a rapid grower un­ is va li d. It's important to note that sotne der cul tivated condi tions. Gray oak is of the larger Gam bel oaks found in south­ perhaps the n1ost widespread oak spe­ ern New Mexico do not have the habit cies of the desett edge in New Mexico of suckering or fann ing clonal groves, occurring as far north as the Zuni and progeny grown fro n1 seed co ll ected Sandia and Manzano Mountains and from those single trees hold true to the south into all the southern n1ountain parent. Likewise seed collected off the ranges. In the Zun is it occurs with lignotuberous ty pes also hold true, hav­ ing a suckering habit.

8. Q. grisea- gray oak D escriJJI ion: Us ua!I y a stna II, low scrubby evergreen tree or shrub, or in better sites a mediu1n-sized tree to 65 feet in height with deciduous leaves when I occutTing at higher and colder sites. It occ urs with Emory oak in the Madrean Oak Woodlands of the desert edge. I ve c Guy & Edith St ernberg i\r/iclwel 1\ lelendre:: among the trunks (~I' a /urge Q. found gray oak in the n1o untains of cen­ grisca in the Tularosa t~founta ins (~{New Alfexico. Ele\'ation 7. ()() () fi . tral New Mexico with nearly evergreen •

Page 26 No.ll/ Fall 2000 International Oaks

Gambel oak and the hybrid called Q. xundulata, or wavy-leaf oak. The larg­ est trees I have found that can be viewed fron1 a car occur at Cloverdale Park in the extreme southwestern comer ofNew Mexico, where they reach 50 -70 feet tall and wide. If viewing this grove, please ren1ember that this is private land stay on the road bed. Leaves are elliptic to ©Guy & Edith Sternberg ovate, 3/4 to 2 inches long, blunt or short­ Guy Sternberg picking seed ofQ. hinckleyi (a f eder­ pointed at apex, rounded or slightly aLLy endangered spec ie~) necw Shafte J ~ Texas. Eleva­ heart-shaped at the base, edges without / ion 4,100 .fi. teeth (except with young seedlings) or with a few teeth toward the apex, thin Texas. This sn1all oak, growing to only and firm, gray-green or blue-green, 3-5 feet tall, is known frotn only a few shiny and sparsely hairy above, beneath locations in the United States, but is densely hairy. Bark is fissured and with believed to be in Mexico also. It is ever­ shaggy plates, light gray. green, spreads underground, and fonns thickets on so1ne of the tnost awfhl, dry, 9. Q. havardii - Havard shin oak hot, sloped areas you will ever see in the Also known as scrub oak, shinnery Southwest. It is an oak of the true desert oak, and sand oak. scrub fonnation. Leaves are much like Description: A shrub to six feet tall, those of Q. turbinella, with sharp spine­ characteristic of the deep sands and tipped lobes. sandy grasslands around the eastern borders of the Chihuahuan Desert in New 11. Q. intricata- Coahuila scrub oak Mexico, Texas and into Oklaho1na. This Description: A thicket-fonning oak to is a true grassland oak, spreading by I 0 feet tall under cultivation, with stnall extensive rhizotnes forn1ing the largest evergreen leaves having si Ivery continuous oak ''forests" in the western indumentun1 on the underside. It is a part half of the United States. When planted of the chaparral and the oak woodlands in a soil of deco1nposed granitic clays, it forn1ation. Found in Texas at the Laguna grows rapidly into a 15-foot tree with little Meadows of the Chisos Mountains and rhizome habit. Of interest are the large, in the Eagle Mountains in Hudspeth sweet, annual acorns. County.

10. Q. hinckleyi - Hinckley oak J Description: A rare, endangered spe­ cies oflin1estone soils in Presidio County, contd. on pg. 28

No .11 I Fall 2000 Page 27

• International Oaks

• • •

contd. from pg. 27

I 2. Q. laceyi (often confused with Q. can be found. glaucoides) - Lacey oak Description: Bur oak is more often Description: A beautiful oak to 25 feet found as a large deciduous tree of east­ tall with blue-green deciduous leaves. ern and mid-western savannas. In east­ Fall color is a sn1okey pink with sotne ern New Mexico it is found in shin oak orange and yellows. A rather rare tree savanna swells called buffalo wallows. found in the chaparral, grama grass­ This is a Large, fast-growing tree with lands, canyon scrub of Texas, and tem­ spectacular leaves of over 12 inches in perate areas of northern Mexico. In the length. In the Roswell, New Mexico area .. Trans-Pecos Reg-io11 it is found on hard ~here are examples of this plant growing 1i1nestone in Terrell County, in the left­ In yards of long abandoned homesteads land shut-up of the Solitario and in ' where the only water is fron1 the natural Mouse Canyon in the Chisos Mountains precipitation of less then 10 inches per of Big Bend National Park. In New year. I suspect these plants were col­ Mexico there are Lacey-like oaks grow­ lected from nearby relict stands, giving ing in the south-centraltnountains that them the natural adaptation for this hi oh look I ike non-evergreen Mexican blue b desert clitnate. If this is not a low-water oaks. This may be the case with some of tree, then I don't know what is! the so-called Mexican blue oaks reported to be in Texas. Lacey oak grows wei Lfor 14. Q. mohriana -Mohr oak us in a heavy clay soil, adding two feet Description: A tree to 40 feet tall, char­ or n1ore in height each year. Some fine acteristic of the grasslands and tnontane exatnples of it can be viewed at the Liv­ chaparral of the litnestone soils ofTexas ing Desert Museum in Carlsbad, New and New Mexico. This is a thicket former Mexico where it grows rapidly into a fine and is one of the more widespread of the tree. It has hi gh heat and drought toler­ Chihuahuan Desert oaks in the Trans­ ance, and is perhaps the best of all the Pecos. Leaves are tardily deciduous, gray southwestern oaks for landscape use. on top and Inuch lighter on the under­ side, close to those of the gray oak. 13. Q. n1.acrocarpa -bur oak Benny Simpson, the famous oak expert This species is a rare find in New frotn Texas A&M University, felt that Mexico, with a relict population occur­ Mohr oak was worthy of cultivation as ring near the san1e area that Q ..fu s ~formis an amenity plant and should be used

age 8 No.ll/ Fall 2 International Oaks more widely. I' n1 not sure its been used prec ipitation range of 12 - 18 inches per at all at least on purpose but it n1ay have year. 1t is not fo und in Ari zona., but can useful applications in hi gh and dry land­ be found in srnall nutn bers in the Davis scapes of the desert edge. Where Mohr Mountains and the Chi os Mountain oak and 1-l avard shin oak grow adj acent of West Texas. It is noteworthy because to each other, a cornmon hybrid occurs of its unusual distribution and iso lated that forn1 a 20-foot grove which is use­ New Mex ico localities westward of the ful as a wildlife shelterbelt or as a wind­ lin1its of continuous distribution in west­ break. Exan1ples of thi s hybrid can be ern Oklahon1 a and central Texas. Leaves seen ofT Interstate Route 40 from Shan1 - are obl ong or broadly lance-shaped, 3 rock Texas heading into we tern Okl a­ to I 0 inches long and l to 6 inches wide, holna ., in areas of deep sand . short or long-pointed, usually rounded at the base; edges wavy to sli ghtly lobed 15. Q. 1n uhlenbergii - chinquapi n oak with curved teeth, dark glossy green Description: This is a tree growing to above., paler and fin ely hairy beneath. 60 feet tall in the Chihuahuan Desert, but Acorn 1/2 to I 1/4 inches long, obl ong, n1uch larger in the n1ore hun1id areas to half enclosed by a deep cup dark choco­ the east. This is one of An1erica s tnost late brown. Bark thin, fissured and fl ak­ regal oaks, and seed frotn this desert ing on stems greater th en 3 inches in provenance should be widely pl anted in dian1 eter, light gray to a crean1y white. Arizona, New Mexico and western Texas. Distribution: In our area it is a tree of the 16. Q. ob long~fo lia- Mex ican blue oak oak woodlands and tnontane chaparral, Description: A s1nall tree to 30 feet and it has th e broadest natural geo­ with trun ks up to 1.5 feet in·dian1eter and graphic and habitat range of any of the with a spreading rounded crown, or a Tetnperate-Zone oaks of the United shn1b at higher elevations. States. Chinquapin oak ranges in the Di ·tribution: In Ari zona and in New United States fron1 northwestern Florida Mexico this oal is a part of the canyon north to Vermont, west to Wisconsin and desert scrub-grassland fo rn1ation, as Io w a, and S0uth to Texas. 1t is very rare we ll as the n1 ontane chaparral and oak and local in n1ountain canyons of south­ woodlands a sociations. In the low-el­ eastern and south central New Mex ico, evati on rn oun tains of extreme south­ bordering the eastern plains. In New western New Mexico (the Gray Ranch • Mexico this species is fo und grovving in area of the New Mex ico panhandle) this the Capitan and Guadulupe Mountains is a cotn mon oak of the Coronado Na­ associated with the bigtooth n1apl e., all i­ tional Forest fron1 4,500 feet to 6,000 feet gator juniper, sandpaper oak and sotol. lts elevati on range in New Mexico i from 4,000 feet up to 7 000 feet with a contd. on pg. 30

No .11 I Fall 2000 Page 29 International. Oaks

• • • contd. from pg. 29

in elevation. It also occurs in the north­ growing juvenile growth), thin and finn, ern Mexico states of Chihuahua and without hairs, blue-green in su1n1ner and

Sonora. This is a confusing tree in Texas tun1ing more blue during winter months. . ~ I because few of the tnajor floras listed it. The bark is unique among all the west­ Yet Sargent described it in 1905 as being ern white oaks, with small, fissured, in the Chi sos Mountains of western square plates, and is light gray in color. Texas, but co1nparatively rare in this area. 17. Q. organensis (Q. Xorganensis?)- Organ Mountain white oak See Q. polymorpha below. Found grow­ ing in only one small population on the west slope of the Organ Mountains east of Las Cruces, New Mexico. In the wild, the parent plants have large evergreen leaves (up to 5 inches x 2 inches), sn1aller than those ofthe Mexican Q. polymorpha, but much larger then either the Arizona ~Q Guy & Edith Sternberg white oak (Q. arizonica) or gray oak (Q. Author Al/ichael A!/elendrez slancl~· under a large Q. organensis in the arroyo hefoyv Dripping Springs, in grisea). It has been suggested that it is a I he Organ Mounwins of southern New Me.xico. El­ natural hybrid of Q. arizonica X Q. grisea, eva! ion 6, I 00 .fi. but our work in propagating it suggests It has been reported in the Bofecillos the progeny are n1ore si.milar to Q. Mountains of Texas which are adjacent polymorpha. Unlike tnost other oak hy­ to the Chisos. The only oaks that I've brids, the Organ Mountain white oak is seen in the Bofecillos or the Chisos that very stable, with the progeny holding true. look like Mexican blue oak are in fact Lacey oaks, which are not evergreen. 18. Q. polymorpha- Monterrey white oak Large exatnples of this oak can be found This is a newly discovered oak for the at Cloverdale, New Mexic~ , with some United States and the Chihuahuan Desert trees gro\ving up to 70 feet tall. Leaves at Dolan Falls, Texas. are oblong., 1-2 inches long, rounded at Description: A tree to 70 feet tall with both ends or heart-shaped at the base, irregular crown. Leaves are evergreen to edges without teeth (except on fast- tardily deciduous, large, glossy above,

Page 30 . No.ll/ Fall 2000 • International Oaks

rusty floccose beneath. Distribution: a Carlsbad. Fall color can be a crimson red wide distribution in Mexico, and south to that is long lasting. This could be one of Guatetnala. Found in Val Verde County, the n1ost ornamental high desert trees for Texas in only one location thus far, near the sn1aller landscapes of cities. Dolan Falls on the Dolan Falls property of the Texas Nature Conservancy. There 20. Q. pungens var. vaseyana (synonytn are three large trees that appear pure Q. vaseyana)- Vasey oak and several up and down a rocky creek A tree to almost 50 feet, but usually a that could be hybrids. Young, vigorous thicket-forming shrub. Seen in its purest growing trees in our nursery resetnble form on the Edwards Plateau and enter­ an evergreen chinquapin oak, but with ing the Chihuahuan Desert in Terrell, a more hooded, waxy leaf. Seedlings of Crockett and Val Verde counties, Texas, it the Organ Mountain white oak look intergrades with sandpaper oak, espe­ identical to Q. ]Jolymorpha seedlings cially in Brewster County and Eddy of equal age and treatment, even with­ County, New Mexico. The leaves ofVasey out rapid juvenile growth. Organ Moun­ oak are not rough like sandpaper, are not tain white oak (Q. organensis) often has nearly as pungently crisped, and are a been considered a hybrid of Q. bright, pea green. Like sandpaper oak its arizonica and Q. grisea, but the prog­ leaves are tardily deciduous, and both eny, when given equal treatment with species give the appearance of small holly Q. polymorpha, suggest to me that it (flex) trees, not oaks. The Eddy County, may not be a hybrid of those species, New Mexico population of this species or a hybrid at all. will turn a bright critnson late-Fall color it holds all winter. In the lower Blue Creek 19. Q. pungens var. pungens - sandpaper Canyon of the Chisos Mountains, Vasey oak oak is seen in pure form weeping over the This is a tree sotnetimes reaching 20 dry stream bed at 4,500- 5,000 feet eleva­ feet tall, but usually a shrub, much lower tion, looking sotnewhat like a white-oak and thicket fanning. The evergreen to version of Q. graciliforn1is, which is sub-evergreen leaves are s1nall, undulate, nearby. Vasey oak is a member of the crisped, with mucronate tips and a defi­ grasslands, desert sctub, and oak wood­ nite sandpaper feeling, and with a blue­ lands associations, and is not found in gray cast. Thjs is a shrub-tree ofthe desert Arizona. scrub, canyon scrub and montane chap­ arral associations. It is thicket forming in 21. Q. rugosa- net leaf oak (synonyms: Q. the grassland and chaparral. The easiest reticu lata and Q. diversicolor) place to see sandpaper oak is to the left Description: An evergreen tree to 40 of the entrance to the Lincoln National Forest on New Mexico Route 137 out of contd. on pg. 32 International Oaks

• • • contd. from pg. 31 feet tall with a broad rounded crown, or a Distribution: 4,000 to 7,000 feet eleva­ shrub. Leaves are beautifu l and rugose, tion, Mexican Border region, fo und in the obovate elliptic gray-green to bri ght tnontane chaparral and oak wood lands green. This species can vary quite a lot in associations ofA rizona and New Mexico. the size and shape of the leaves, frotn a In Arizona it fonns an open fo rest on the large Q. po(vn1orpha-like fo nn, to a small Mule Moun tains in Cochise County and Q. turbinella-like form but without tn u­ in Texas Canyon east of Benson; in New cronate lobes. Mexico, in the chaparral and oak wood­ Distribution: A n oak of the n1ontane lands of the Peloncillo Mountains in chaparral and oak woodlands at relati vely Hidalgo County. I have not seen it in Texas high elevations. It is a rare oak in Texas, but Cornelius Mull er pl aced it in the but more con1tnonly in the Black Range, Franklin Mountains and the Qui ttnan Diabl o Mountain and the Mogo llons of Mountains. Richard Spell enberg has re­ the Gila Nati onal Forest of New Mex ico viewed those specim ens from the and found in all the southeastern moun­ Franklins and does not concur. Van tains of Arizona bordering New Mexico. Devender and Ri ski nd found Q. tou1neyi Acorns are attached to long peduncles. debri s to be very common to abundant in The bark of the nctleaf oak is sitnilar to packrat 1niddens at Hueco Tanks State that of the chinquapin oak, with a fl aking Park dating back to the late Pleistocene habit on stnall branches. Q. rugosa may to early Holocene 13 000-8 000 BP. be the tnost ornatnenta1 sn1 all evergreen tree in the Southwest, with the potential 23. Q. turbinella - scrub Ii ve oak of being used into USDA Zone 5 of the Description: An evergreen shrub to a Midwest. Netleaf oak shares with chin­ stnall tree of 15 feet with son1e exceptional quapin oak the ability to grow we ll in trees reaching 30-35 feet. Scru b li ve oak heavy, moist clay soils of hi gh pH. is an attractive small oak and one that people in the Southwest are rnore fa mi Ii ar 22. Q. tounrzeyi- Tourney oak vvith because it's fo und closer to AIbu­ Description: A tree or shrub up to 30 querque and El Paso than other nati ve feet tall. Leaves are stnall, entire, ovate, oaks. Leaves are stnall elliptic or oblong, and evergreen. Aco 111 s I/2 to 3/4 inch one-half to one inch long., short -po.in t ed long, with shallow cups. Bark thin, scaly edges with spine-like teeth thick and stiff or fla ky, dark brown. above blue-green with a bl oom and International Oaks nearly hairless, beneath yellowish green to white oaks (except for those of Q. and finely hairy. etnoryi, which are sweet). It has been said Distribution: Lowest elevation occur­ that red oaks in general are not as drought rence: Organ Mountains at 5 000 feet resistant as the white oaks, although Sandia Mountains at 5,700 feet, Gila Na­ some clai'tn the reverse is true. tional Forest at 4,400 feet. It is co1nmon in the chaparral and oak 24. Q. canbyi- Canby oak woodlands of Arizona This species of red oak and New Mexico. A fine is found at high elevations location for viewing this in the n1ountains of north- species is on the west easten1 Mexico. It looks a slope ofthe Sandia Moun- lot like the Langtty oak and tains (outside of Albu- the graceful oak (Q. q uerque) on the Juan gracilijorn1is). The acorns Tabo picnic grounds road. mature in one season. We ln Texas its greatest occur- have a specimen that was renee is in the Franklin grown from an 8,000-foot Mountains, but it can also provenance, and it is per- • be found in the Eagle and fanning well at our arbore- Quitman Mountains of tum. With rapid growth ~Guy & Edith Sternberg Hudspeth County. It addingabout4to5feeteach An old treeh ouse built in a Q. should be used much emoryi located in Glenwood. New sumn1er, and the last flush more widely in the Mexico sen •es as a p erch for of growth taking place in Chihuahuan Desert and in authorlvlichael lvlelendrez. late Septetuber, it still seems other areas where drought tolerance is to harden up enough for the first hard sought. lt n1ay be the hardiest of the ev- fl-ost ofOctober. It is se1ni-evergreen here ergreen oaks in cold winter areas. and gives a maroon winter color that can last for tnonths. It is reported to grow well BLACK OAKS or RED OAKS on soils of alkaline limestone origin. (Section Lobatae, or Subgenus Erythrobalanus) 25. Q. en10l)li- En1ory oak Bark black and furrowed, leaves, if Also called bellota (aco111) oak black­ lobed, with bristle (aristate) tips, wood jack oak and black oak. without tyloses. Acorns take two years Description: A tree typically 40 to 60 to 1nah1re (except for Q. en1oryi and Q. feet tall , except in western New Mexico canbyi, that n1ature the first year, and Q. where specimens can be found up to 100 hypoleucoides, which mature either the first or second year), acorn cups tornen­ tose inside, acorns quite bitter con1pared contd. on pg. 34

No .11 I Fall 2000 Page 33 International Oaks

• • • contd. from pg _ 33 feet tall and with trunks in a wide arrangernent of ( over 7 feet in diamete1: Large soils or rock types, from trees look tn ucl1 like the fine alluvial fills to gravel • southern live oak of the and cobble arroyos, lime­ Southeast, with large hori­ stone to granite, and sand­ zontal branches swooping stone hilltops that are ex­ down to the ground, but cessively draining with no with taller, domed crowns topsoil developtnent. The reaching as high as 100 potential is there for an ex­ feet. A typical large speci­ cel lent large tree for the n1en may reach 60 feet tall high and dry landscapes by 10 0 feet wide. I ' v e of the Southwest and counted over 600 annual West Coast. rings on sotne branch cuts <.'Guy & Edith St ernberg Distribution: Occur­ that are 4 feet in diameter. Nle/endrez sits in the .fork of Q. ring in Catron, Dona Ana, This slow growth is a re­ emoryi near GlenH'Ooc/. New Hidalgo, Luna and Sierra sult of the aridity of this i\1/exico. Elevation 5,000 ft. This Counties, New Mexico, in specimen is I 8 feel in circumfer­ region. Leaves are ever- ence. and 111Cil' become the n e 'I-V na- open desert scrub/grass­ • green to tardily deciduous, tiona/ champion for this particular land sites starting at 4,000 • dar 1

Page 34 No .11 I Fall .2000 International Oaks

• • • contd. from pg. 35

I and Lamb in Oaks ofNorthAmerica. This inch long, pointed, one-third enclosed in oak is found in canyons or mountain a thick cup that is hairy inside, and col­ slopes in montane chaparral and oak ored a light grayish green when ripe. woodland at about 5,000 feet or higher in Distribution: A beautiful oak of the the Chisos, Del Norte and Glass Moun­ high canyons in the oak woodlands, gen­ tains, in Brewster County, Texas. Also in erally above 7,000 feet, in southeastern the Davis and Vieja Mountains, in Jeff Arizona and southwestern New Mexico, Davis County; in the Madera Mountains, but found as low as 4,000 feet and as high in Pecos County; and perhaps in Val as 9,000 feet in New Mexico. Found in Verde County. Chisos red oak can be Texas only in the Davis Mountains ofthe found on both igneous and limestone Trans-Pecos region. soils, and trees from each edaphic prov­ enance do well at the Texas Agricultural 29. Q. (x?) sp.- Langtry red oak Research and Extension Center at Dallas. This is a controversial evergreen red oak to about 50 feet tall, found in the head 28. Q. hypoleucoides - silverleaf oak canyons of the Rio Grande River just be­ Also called white-leaf oak. low the confluence of the Pecos River. (synonym: Q. hypoleuca) When Major En1ory did the Mexican Description: A stnall to tnedium tree boundary survey in the early 19th cen­ 35-40 feet in height, with some exceptional tury, this oak was found in at least one trees in the Gila Wilderness being over 80 head canyon of the Rio Grande and was feet tall. Trunks in the deep canyons of reported as Q. coccinea var. microcarpa. the Gila can be single stetn, with clear Cornelius Muller said this specimen is boles of30 feet or 1nore and diatneters of clearly representative of Q. gravesii, and 3 to 5 feet. It is sometimes a clump-form­ he postulated that it was probably col­ ing shrub 6 to 20 feet tall on dry, south­ lected in the mountains farther west. Af­ facing scree slopes. Leaves are lance- to ter over 100 years, the oak was found willow-shaped and evergreen, to 1 inch again, and Muller once again tentatively wide and 4 inches long. Leaf edges are identified it as Q. gravesii. However, after revolute (rolled under), and the blades are growing this oak out in New Mexico and sn1ooth, blue-green on top and silvery seeing it at the Texas Agricultural Experi­ tomentose on the undersides. Acorns are ment Station at Dallas, it appears to be a annual (or sotnetimes biennial), I /2 to 3/4 completely different species. International International Oaks

Oak Society 1nen1ber Pat McNeal of n1uch 1ik e the Paltner oak. Acorns are 5/8 McNeal Growers feels that there are sev­ to I l /2 inches long broad, maturing in 2 eral populations of oak that all could be years. The large cup is a spreading, tur­ Langtty oaks. Pat has probably seen n1ore ban-like cap sometimes reaching 1/4 inch examples of this oak (in the wild and un­ or tnore out from the acorn sutface. The der cultivation) then anyone else alive, inside surface of the cup is covered with and feels it is unique when con1pared to a fine golden coat of hairs. The bark is the other red oaks of the region. I trust fissured into narrow scales and flakes, Pat and accept his opini on that the gray or dark gray. Langtry oak is a distinct species and not Distribuhon: Q. chrysolepis grows just a hybrid. from the coastal and transverse moun­ tains of Californi a into the south western mountains ofNew Mexico in Catron and GOLDEN OAKS Grant Counties. It is never cotnmon in Section Protoba!anus (formerly subge­ southeastern Arizona or New Mexico but nus Protobalanus) can be fo und easil y in California, in areas as cold as the north shore of Lake Tahoe 30. Q. chrysole]Jis- canyon live oak near the Cal-Neva Hotel. In canyons and Native to the tnountains of California on Jn ountainsid es it often forms low­ Arizona and southwestern New Mexico, growing thickets or woodlands, fron1 el­ this species is vari able in fonn size and evation 3,500 up to 7,000 feet. leaf. Description: Evergreen shrub to large 31. Q. palmeri- Palmer oak tree growing up to 50 feet or tall er in the Also called the Canyon li ve oak. n1ountains of California but usually a (Q. . chrysolejJis va r. pahneri, Q. dunnii) small tree to 25 feet in the Southwest. lt Descri]Jfion: An evergreen shrub or can have a ta ll , pole-) ike structure with small tree, usually 6 to 25 feet tall and up strong apical dominance and short hori­ to 6 to 10 inches in trunk diameter., with a zontal branches. Larger trees in Califor­ dense, bushy, wide-spreading crown. nia may be n1ulti -trunked with a wide Leaves are spiny-toothed, elliptic to ovate, spreading, n1assive structure. Leaves are 1 to 2 inches long, edges crisp and leath­ entire on n1 ost n1ature trees, ovate, 1 to 2 ery shiny yellow-green to dark green inches long, blunt or shoti-poi nted at the above and slightly yellowish to white apex, finn, with a dark, shinny green sur­ beneath. Acorns are 5/8 to 1 inch long, face and light whitish-green underside. broad., n1 aturing in the second year. The On seedlings or rapid growing juvenile trees, the leaves can be spiny toothed contd. on pg. 38

No.ll I Fall 2000 Page 37 International Oaks

• • • contd. from pg. 37 cup is spreading (but not as turban spiny, evergreen leaves resembling the shaped as that of the canyon live oak), - juvenile foliage of the canyon live oak with fine golden hairs covering the in­ and spiny forms of the holly oak (Q. ilex) side. of Spain. All three can display entire leaf Distribution: Canyons and margins with slower growth at 1naturity. mountainsides of the Southwest, eleva­ Under nursery cultivation, they easily can tions 3,500 to 6,000 feet; New Mexico in be confused. All can be rapid growers Catron, Hidalgo, Grant, Luna and Sierra under cultivation, adding 3 feet or more Counties; Arizona in the mountains of each year. southeastern and central parts; south and west of the Mogollon Rim. Also found in Copyright© 1996, Michael Martin Melendrez southern Nevada, southwestern Utah Revised by Sternberg and Coombes, 2000 and southern California. Palmer oak has

Oetober 29 ·Nov ber 4 • Oct. 29 - Opening banquet and pre-conference trip • Oct. 30-31 -Seminars, meeting, exchange • Nov. 1-4- Post conference trips

• For details, visit us online: http://www.saintmarys.edu/--rjensen/newconf.httnl Oak

Page 38 No.ll/ Fall 2000 International Oaks

------~ ·- •-·--

by Francisco Maria Vazquez, Francisco Esparrago, Juan Alfonso Lopez Marquez, Fernando Jaraquemada, and Maria del Carmen Perez

Servicio de Investigacion Agraria Junta de Extremadura Direccion General de Investigacion y Capitacion Agrarias Consejeria de Agricltura y Comercio

A total of eight ecotypes of Quercus rotundifolia occurring in Extremadura, Spain, are described. The differences betvveen ,. them are based on the external morphological characteristics of the fruits. Also included is a key to the identification of' the different forms and a description o.f each one, including its distribution within the region. Key words: Quercus rotundifolia, ecotype, acorn, cupule, form, Extre1nadura, distribution

ecause of the large interest in keeping pigs in Extremadura, Spain, the dehesa ecosystem is based on making use of the fruits of local trees. During I 988, a project was carried out to identify the most notable characteris­ tics of the fruits of the oaks. Initially the project was only de-

contd. on pg. 40

No .11 I Fall 2000 Page 39 International Oaks •

lia ... contd. from pg. 39

Methodology The tnethod of study was based on the collection oftnaterial in Extremadura according to the National Forestry In­ ventory in Extremadura and aerial pho­ tographs ( 1984) existing in the Agricul­ tural Research Service. Collections were madebetweenAprill988andJune 1990.

~Guy & Edith Sternberg Sotne specimens off. pilosella were col­ lected between 1995 and 1997. Branches Quercus rotundi folia as seen in southern France. bearing leaves and inflorescences were collected from 10-25 trees at each local­ signed to make an illustrated catalogue ity. This material was pressed, dried, and of the fruits to show their shape, size, then studied in the laboratory. Data on color and weight. However ecotypes leaf tnorphology and stem and flower were detected that clearly defined dif­ characteristics were recorded. Whole ferent types of trees. fruits (cupule and acorn) were collected According to the data obtained and weighed fresh and dry after 24 hours through fieldwork, the morphological at I 00°C, and data on their weight and characters studied in the laboratory, and morphology were recorded. Tables of the the literature consulted, the existence of characters were made from the data and a group of ecotypes was discovered, a description was made for each of the which are perfectly differentiated by the variants found. These were then com­ external morphology of their fruits. pared with descriptions in the literature. The main part of this work concerns the infraspecific taxa of Quercus Results rotund(folia Lam. in Extretnadura, and The officiaJ description of the species shows the characteristics which differ­ includes the following. entiate them and their distribution. A key to distinguish the different taxa is also Q. rotundifolia Lam., Encycl. 1 : 723 included. (1785) Q. ballota Desf., Observ. Phys. 38: 375, pl. l (1791 ). International Oaks

. Q. ilex L. subsp. ballota (Desf.) Samp., anthers. Female flowers solitary or in Bol. Soc. Brot. 24: 102 ( 1908-1909). clusters of up to 4 , on pubescent Q. ilex subsp. smilax (L.) C. Vicioso., Rev. pedicels, perianth with 6 hairy lobes. Gen. Quercus Espana 166 ( 1950). Stigmas commonly 3, occasionally 4. Q. ilex sensu Brotero, Fl. Lusit. 2: 3 3 (Maire, 1961 ). ( 1804); B. Gomes, Cond. Flo rest. Port. 60 Fruits solitary or clustered, sessile or ( 1876); Laguna, Fl. Forest. Esp. 1: 252 on a tomentose peduncle to 1.5 em; (1883); P. Coutinho, Bol. Soc. Brot, 6: 94 cupules grey, tomentose, hemispherical (1888). or somewhat attenuate at the base, 0.5- Q. ilex susbp. rotundifolia (Lam.) 0. 2.5 em across, more or less covering part Schwarz ex Tab. Morais, Bol. Soc. Brot. of the acorn; scales ad pressed, flat or Ser. 2, 14: 122 (1940). slightly thickened, ovate-triangular, Tree to 20 m tall with an erect, obtuse, narrowed to the base on the cylindrical trunk, grey bark, broken into proximal part of the cupule where they stnall plates and a broad, rounded head, are lanceolate to sotnewhat acute. often modified by pruning. Young shoots Acorns very variable, ovoid, ovoid­ densely stellate-tomentose. Buds small, oblong, oblong-cylindric, or ovoid, obtuse with oval scales, brownish subglobose, 11-50 mm long, 12-22 mm tomentose. Stipules caducous. (Vicioso, diam. With a tornentose endocarp and 1950; Schwarz, 0., 1964. Quercus L. in weighing 0.2-8 g when mature and dry. Tutin et al., 1969; Valdes, 1987). Leaves Flowering February to May, fruits 1-5 x 1.5-3.5 em, petiole 3-14 tnn1 , maturing from October to November the coriaceous, persistent, pale green when same year. young, grey-hairy on both sides; adult General distribution: It is distributed leaves with upper surface green, fron1 Portugal and Spain to southern glabrous, white-tomentose beneath, France, and North Africa. very variable in shape even on the same Peninsular distribution - The Iberian tree; ovate-lanceolate, elliptic, sotnewhat Peninsula is where it finds its ecological orbicular, ovate-rounded, acute or optirnurn and it occurs over all the terri­ obtuse at the apex, rounded to cuneate tory. It is generally the dorninant tree in or attenuate at the base, entire or dentate, forests less than 1,000 tn in elevation. It sotnetimes slightly mucronate; juvenile is also found in parts of the South of leaves usually with spiny teeth on their France and in some patts of the Cordil­ margins. Secondary veins in 5-8 pairs. lera Cantabrica, the Pyrenees and Male flowers in dense or somewhat lax Cata1ufia. yellow catkins, 3-6 em long with a Distribution in Extremadura - In tomentose rachis, and hairy, lanceolate­ acute bracts; perianth with 3-5 broad, obtuse lobes, stamens with mucronate contd . on pg . 42

No.l-1 I Fall 2000 Page 41 International Oaks

us rotundi lia ... • contd. from pg. 41

Extretnadura it is widely distributed, but differentiate among these eight taxa. It is absent from some parts of the North is based entirely on characteristics of the and South where it is replaced by Q. fruit. pyrenaica Will d. in the highest and cold­ 1. Peri carp pubescent in the apical 1/3 est areas· elsewhere it occurs in the ...... f. pilose!Ia shady and acidic zones in the Sierra de l. Pericarp glabro us or onl y pu bescent San Pedro and Jerez de los Caballeros at the acute apex ...... 2 with Q. suber L. lt is threatened by de­ 2. Acorns less than 15 min long, not or forestation in La Serena, Tierra de Barros, hardJ y exserted from the cupul e ...... Llanos de Caceres and Vegas del f. avellaniformis Guadiana. Sometimes it appears tn ixed 2. Acorns more than 20 mm long, clearly with some individuals of Q. coccifera L. exserted from the cupul e ...... 3 in calcareous areas, and very locall y with 3. Cupules less than 16 mm long ...... 4 Q. .faginea L . n1ainly in south and cen­ 3. Cupules more than 16 mtn long ...... 6 tral Badajoz (Tentudia Jerez de los Ca­ 4. Cupul es less than 8 mm long, cup­ balleros and Tierra de Barros) and south shaped, floral peduncles short less than and central Caceres (Vi II uercas, 0.5 mm ...... f brevicupulata Monfragli e and Alcantara). 4. Cupules more than 10 mm long, hetn ispherical , peduncles of variable Forms of Q. rotundifolia length sornetimes n1ore than I ctn ...... 5 Based on the data co llected, eight 5. Acorns at least 3 times as 1o ng as fo nns or taxa of Quercus rotund[folia broad, cupules somewhat thickened and were identified. They are listed below: hazelnut-shaped, with a s1nall ring in the f. rotundffolia lower part ...... f. crassicupulata f. brevicupulata 5. Acorns less than 3 times as long as f. avellantforn?is wide, very variab le in shape cupules f. expansa he1n ispherical truncate, rounded or f. crassicupulata somewhat acute at the base, without a f. calcyna ring in the lower part ...... f. rotundijolia f. lnacrocarJJa 6. Cupule broad, bell-shaped, thickened f. pilose/fa and folded at the margin which resembles a n• ng ...... f. expansa The fo ll owing key was developed to 6. Cupule broad or narrow sometitnes International Oaks

bell-shaped but with the margin sn1ooth, not thickened ...... 7 7. Acorns up to 37 mtn long and 15 m111 across, with cupules covering at least 2/ 3 of their length, turbinate at the base ...... f. calcytla 7. Acorns 1nore than 39 mtn long and 19 1nn1 across with hetnispherical cupules truncate or son1ewhat rounded at the base and covering at most I /3 of the length of the acorn ...... f. macrocarpa

Descriptions follow of the vari ous I I fonns tnentioned in the diagnostic key. I Synony1ns are included for each of the fonns recognized, as well as drawings to - show differentiating characters usefu'l to _ I CM separate one fom1 frotn another. Q. rotundij'olia Lan1. f. rotundifolia Foliage andfru it ofQ. rolundifol iaf rotundifol ia. Q. ha/lota var. parvtflora Cohneiro & E. Q. ilex var. ballota f.laur[folia Maire, Fl. Boutelou, Exatn. Encin. 10 ( I 854). DeL' Afrique du Nord. 7: 123 (196 1). Q. ballota var. obovatifolia Colmei ro & Q. ilex var. ballota f. laf!folia Maire, Fl. E. Boutelou, Exam. Encin. 10 ( 1854 ). De L'Afrique du Nord. 7: 122 (196 1). Q. balfota var. grandifolia Colmeiro & Q. ilex var. ballota f. coutinhoi Maire, E. Boutelou, Exam. Encin. 10 (J 854). Fl. DeL' Afrique du Nord. 7: 123 (196 1). Q. ballota var. mascula Colmeiro & E. Q. ilex var. ballota f. .JJendula Maire, Fl. Boutelou, Exatn. Encin. 10 ( 1854). DeL' Afrique du Nord. 7: 123 ( 196 1) . Q. ilex f. ole ~folia Laguna, Fl. For. Esp., • I: 255 ( 1883) . Trees of very variable size and shape, Q. i/ex f. 1nicrocarpa Laguna., Fl. For. hairiness of leaves, and in the habitats Esp., 1: 257 (I 883). in which they are fo und. Cupu les 9-15 Q. ilex var. bal!ota f. vulgaris Cout., Bol. mtn long, he1nispherical, somewhat cup­ Soc. Brot. 6: 94 ( 1888). shaped, truncate or rounded at the base, Q. ilex var. ballota f. oleo ides Cout., Bol. 1 or 2 on each peduncle, bracts triangu­ Soc. Brot. 6: 94 ( 1888). lar-acute at the base, becon1ing linear Q. ilex var. ballota f. macrophylla Maire, towards the base of the cupule, flat, to- Fl. De L'Afr1que du Nord. 7: 123 ( 196 1) . Q. ilex var. baflota f. n1icrophylla Maire, Fl. DeL' Afrique du Nord. 7: 123 ( 1961 ). contd . on pg . 44

No.ll I Fall 2000 Page 43 International Oaks

lia ... contd. from pg. 43

•

/ / " , . ; . ; ,· •

.._~0.5 CM

Foliage andjhlil r~f'Q . rotundi fol iaf brevicupulata. tnentose. Leaves very variable in shape higher zones, planes in sunny and shady and size on the same tree. Acorns vari­ sites on steep slopes etc. able, 30-40 (45) mm long, 12-17 (20) mrn across 1/4-2/3 covered by the cupule. Q. rotundifolia Lam. f. brevicupulata Weight 1.5-5 g when n1ature and dry. (Laguna) F.M. Vazquez, Semillas de (Vicioso, 1950; Maire, 1961 ). Quercus: Biologia, Ecologia y Manejo, Distribution in Extremadura- Its dis­ 83, 1998. tribution is the same as that given for basionym: Q. ilex f. brevicupulata La­ the species. It is the form widely di strib­ guna, Fl. For. Esp. 1, 256 ( 1883) uted and it is indifferent to soil and Q. ilex subsp. smilax C. Vicioso var. ecological conditions, occurring in the brevicupulata (Laguna) C. Vicioso., Rev. International Gales

Gen. Quercus Espana 172 ( 1950). Tree of variable size found in many different habitats. Cupule cup-shaped, very broad with an erect 1nargin, without a ring, ( 15) 17-19 (21) x (5.0) 6.5-7.0 1111n, on a short peduncle no more than 0.5 rn1n or .____. 0 . 5 CM s e s s i I e , w i t h fl at scales not thickened Foliage tmt//htil (~/Q. rotundifoli af ave ll anifonnis. as in f. n1acrocarpa, closely adpressed, ton1entose, triangu­ Q. ilex var. ave!lan[(orn1is (Coln1eiro & lar-acute. The cupuJe only covering the E. Boutelou) Cout. , Bol. Soc. Brot. 6 95 base of the acorn. Leaves oval to elliptic ( 1888). or orbicular, not useful for identification. Large to SinalI tree with thick bark and The leaves can be spiny when juvenile, totnentose shoots; cupules ( 12) I 3-14.5 but then only weakly (Laguna., 1883). ( 16) x 14.5-15.5 n1tn, peduncles 8- 15 111111, Acorns oblong truncate at the base, 28- bearing 1 or 2 fruits. Scales lanceolate 30 (34) x ( I 5) 16-18 1111n pale brown when acute and adpressed, very totnentose. dry (C. Vicio s o~ 1950). Weight2-5 gwhen Cupule hen1ispherical, sotnewhat nar­ tnature and dry. rowed to the base where the scales are Distribution in Extrentadura - Tt is srnall er and less ton1entose (Cohneiro & very widely distributed in the region, but Boutelou, 1854 ). Leaves weakly hairy sti II has not been found north of the area when young ovate varying to of Sierra de San Pedro and ofVilluercas, subelliptic, entire subobtuse, but juve­ or in the sn1all areas of forest wh ich are nile leaves can be acute and spiny. Veins still present in Llerena and Tierra de very prorninent on the undersurface of Barros. the leaf. Acorn shaped like a hazel nut very stnall 12- 14 ( 16) x (8.5) 9.5-1 0.5tnm, Q. rotund~folia Lam. f. avellan~forn'lis with a vety sweet taste aln1ost completely (Cohneiro & E. Boutelou) F.M. Vazquez, covered by the cupul e and difficult to Sen1i llas de Quercus: Bio1ogfa Eco logia extract fron1 it (C. Vicioso 1950). Weight y Manejo, 83 ( 1998). basionyn1: Q. avelfantforntis Cohneiro & E. Boutelou, Exa1n. En c. 9 ( 1854) contd . on pg. 46 International Oaks

rotundi lia ... contd. from pg. 45

0.2-0.5 g when n1ature and dry. Esp. 1: 25 6 ( 18 83) Distribution in Extren1adura - Very Q. ilex var. expansa (Poir.) A. Can1us, locally distributed. It has only been pos­ Monogr. II 57 ( 1939) sjble to find specimens in the South of Q. ilex subsp. sn1ilax C. Vicioso var. Badajoz, always in places very close to exJJansa (Poir.) C. Vicioso, Rev. Gen. Sierra Morena and in zones with a very Quercus Espana 171 ( 1950). high tree density. We agree with Trees differ from other fonns in their Co uti n ho ( I 8 8 8) in the d i s tr i but ion cupules 16.5-20 x 18-19 (22) mm; broad South of the Peninsula. and bell-shaped the margin covered in folds giving it a more or less pron1inent Q. rotundifolia Latn. f. expansa (Poir.) ring-shaped appearance. Pedicels more F.M. Vazquez, Sen1illas de Quercus: than 1.5 mm long, of n1edium hairiness, Biologfa, Ecologia y Manejo, 83 , ( 1998). with scales ovate-triangular but some­ basionym: Q. expansa Poir. Encycl. Bot. what lanceolate towards the base of the Suppl. 2, 216 ( 18 I I) cupule always obtuse. Fruits in groups Q. ilex f. expansa (Poir.) Laguna, Fl. For. of 2-3 on the peduncle (Laguna, 1883). The leaves show the gen­ eral characteristics of the species and are very vari­ able. Both ovate spiny and entire leaves are -~ ICM found in the juvenile and adult states. Acorns 33- 40 x 14-16.5 mm, ovoid­ cylindrical, slightly trun­ cate at the base, 1/2 cov­ ered by the cupule, very sweet tasting. Weight 2.5- - 5.0 g when mature and dry (Vicioso, 1950). Distribution in • Extremadura - Exarnples Foliage andJi·uil of Q. rolundi folia f ex pan sa. have been found mainly

Page 46 No.ll/ Fall 2000 International Oal

Q. rotuntlifolia Latn. f. crassicupulata (Cout.) F.M. Vazquez, Semillas de Quercus: Biologia, Ecologia y Manejo, 83 , _ tCM (1998). basionytn: Q. ilex L. var. Foliage cmd_fi·uit ofQ. rotundi fol ia f crassicupulata. ballota f. crassicupulata Cout., Bol. Soc. Brot. 6, 95 ( 1888). der (9) 10-11.5 x 32-37 (44) 1111n, more than Q. rotundifolia f. dolychocarpa P. Silva, 3 titnes as long as broad, ochre-coloured BroteiraXII (XXXIX) Fasc. I176-80 (1943) and of sweet taste weight 1.5-3.5 g when As described by Pereira Coutinho mature and dry. ( I 888), this fonn has very large, thick Distribution in Extre1nadura - It is dis­ fruits. It is also di stingui shed by its tri ­ tributed mainly in the central western patt angular-acute bracts, which are very of the .Autonomous Con11nunity, charac­ adpressed and flat, but at the margin of teristically in densely wooded areas. Son1e the cupule they are lanceolate and ob­ individuals have been found in the Sierra tuse, always ton1entose. The shape of de San Pedro, on the border with Pottu­ the cupule is so1newhat angled slightly gal, and the center of Caceres province. hazel-nut shaped with a small ring in the basal part where the scales curve slightly Q. rotundifolia La111. f. calcyna (Poir.) inwards. The cupule is ( 10) 12-1 6 111m F.M. Vazquez et al. , corn b. et stat. nov. long and 12-14 ( 17) 111m across and cov­ basionytn: Q. calcyna Poir., Encycl. Bot. ers 1/5-1/6 of the acon1 (Coutinho, 1888). Suppl.2,216(1811). The leaves, as in forms described above, Q. if ex L. subsp. smilax (L.) C. Vicioso are not useful for identification but show var. dolichocalyx• C. Vi cioso, Rev. Gen . peculi arities in their variability such as: Quercus Espana 170 ( 1950). juvenile leaves spiny, mucronate 1nature leaves lanceolate. Acorns oblong-lan­ ceolate, attenuate at the base, very sJen- contd. on pg. 48

No.ll I Fall 2000 Page 47 International Oaks

rotundi olia . . . contd. from pg . 4 7

diverse grades of • hairiness of the scales. Pedicels 3-4 • mtn long. The leaves do not have distin­ guishing characters, but show di verse shapes found in other forms (C. Vicioso, 1950). Acotns ovoid­ elliptic, obtuse at the base, with a sweet taste and with weight ~lC M 3.5-6 g when mature and dry. Foliage and fruit ofQ. rotundifoJiaf ca lcyna. Distr;bu - tion in Extremadura Q. rotundifolia Lam. £ dolichocalyx - It is found in almost all the territory, (C. Vicioso) F.M.Vazquez, Esparrago, more frequently in areas of extensive and Jaraquemada & Lopez-Marques, Descr. dense oak forests, as it occurs in the Si­ Q. rotundifolia Extre1nadura 13 (1992). erra de San Pedro, Villuercas, Sierra Q. ilex L. f. calycina (Poir.) Laguna, Fl. Morena and on the border with Portu­ For. Esp. 1: 256 (1 883) nom.illeg. gal.

Tree with the same external n1orpho­ Q. rotundifolia La1n. f. macrocarJJa • logical characteristics as f. rotund[folia. (Cout.) F.M. Vazquez, Semillas de It differs in its cylindrical cupules 17-25 Quercus: Biologia, Ecologia y Manejo, (27) x 15-19 (23) mm, which cover at least 83, (1998). 2/3 of the length of the acorn, with ovate­ basionym: Q. ilex L. var. ballota f. triangular, closely adpressed scales; macrocarpa Cout., Bol. Soc. Brot. 6, 95 those of the tnargin are slightly lan­ (1888) ceolate-acute. Towards the base, irregu­ Q. ilex subsp. s1nilax var. macrocarpa larities sometimes appear associated with (Cout.) C. Vicioso, Rev. Gen. Quercus

Page 48 No.ll/ Fall 2000 International Oaks

Espana 169 ( 1954 ). their fruits are intermediate between one This is distinguished fro tn other fo nns and the other, but closer to those of the by its large cupules and acorns. How­ latter. Regarding their leaves, even ever, between th is taxon and f. though the n1ajority arc oval in shape, rotund(folia there is a continuous range on the satne tree we can fmd variations, of ecotypes and tnore than one di fferent with so n1e tnore oblong and so1ne tnore taxon in a nonnal representation of fre­ orbicular. quency. We could refer to all of these as After these considerati ons, we can say f. rotundifolia . This fo rm f. that this taxon has a hetnispherical-cy­ lindrical cupule of 16-20 x 22-26 mm. It n1acrocarpa1 cotTesponds to those in­ dividuals at one extretne of the range. has triangular-acute scales, except the We have considered it as a different ones on the margin which are vety weakly taxon because of the high frequency of lanceolate, strongly adpressed and flat, individuals that show very clearl y the even when so1netitnes they are thicker characteristic ditnensions of the fruits and ash-grey in colour with a long and cupules. pedicel of0.5 to 1nore than l .Ocn1 in length Within the san1e variation between ex­ and with a internal diatneter of 19-22 111m tretnes come the small fruits and sn1all (Coutinho, 1888). Generally the leaves cupul es of Q. ilex f. 1nicrocarpa Laguna are not constant in shape, even though (here regarded as a synonyn1 of Q. they are oval in shape, rounded, with rotundifolia f. rotundifolia) which is the exception of the ones exposed to sun, same as Q. ballota var. obovat{folia Cohneiro & E. Boutelou. This form is contd. on pg. 50 characterized by its oval leaves and its small frui ts and is fo und onl y in ar­ eas south of Badajoz in the same places as f. ave/!anifornrzis, which was also described by Cohneiro and Boutelou. It is possible that Q. ilex f - n1 icrocarpa Laguna and Q. ballota var. obovat[folia Cohneiro &

E. Boutelou are no tnore - 1CM than crosses between f. rotundifolia a nd f. avellanif'ormis because Foliage andfruit c~j'Q. rotund i folia/ macrocarpa.

No.ll I Fall 2000 Page 49 International Oa/(S

• rotund 1a • • • contd. from pg. 49 which are slightly lanceolate and weakly mucronate (C. Vicioso, 1950). For tills taxon the acorns are a very important taxonomic character. Their dimensions range between 38-50 x 19-22tnm, with an ovoid-cylindrical shape, a sweet taste and a weight which varies between 6-8 g - O.SCM when they are mature and dry. Distribution in Extremadura - This Sterile form ofQ. rolundifol ia originally described form was described for the Portuguese as Q. ballota var. 1nascul a Co/meiro & E. Boutelou. here regarded as a synonym ofQ. rotundi fo liaf Flora by Coutinho ( 1939) from material rotundifo li a. from the border with the south of Extremadura. Groups of examples have when mature and dry. been found only in two places; one in Distribution in Extremadura- This is the south of Badajoz and the other in the typical taxon of the south and east the region of La Serena. We also believe forest ofBadajoz province. It can be found that there is a continuous distribution in closed forest, with low levels ofhun1an between these two zones. disturbance or with an equilibriu111 be­ tween tnan and medium (forest). It grows Q. rotundif'olia Lam. f. pilosella F.M. in tnountainous areas with indifferent Vazquez, Sen1illas de Quercus: Biologia, soils, at n1oderate altitudes (500-700 m) Ecologia y Manejo, 84, (1998). and rainfall (400-800 1nm/year). This form differs from the others men­ tioned in the pubescent pericarp. Small Discussion trees to 6 tn tall; leaves small, entire or Frotn the start of this project, we found with spiny margins, stellate-pubescent on no consistent differences among the the abaxial and adaxial surfaces. Cupule various taxa in their leaves, scales, l 0-12 mm long, subspherical, rounded at pedicels, bark morphology or canopy. the base, with a short peduncule up to 6 Some of the taxa were described, based tum, 1-3 on each peduncule; bracts trian­ on these characters, and so the different gular, flat, tomentose. Acorns 20-37( -40) variants and forms based on descriptions tnm long, 8-12( -15) mm across, 1/3-1 /2 of foliar morphology have not been covered by the cupule. Weight 1.2-4 g taken into account, even though we

Page 50 No.ll/ Fall 2000 International Oaks found these possible taxa. It has been Caceres with higher rainfall (>800 tnm/ proved in the 1naterial san1pled that leaf year); Q. coccifera L. in the warmer parts tnorphology varies according to the phe­ ofExtretnadura; Q. suber L. in some areas notypic variabi 1ity of the genotype due with acid substrates and an a1u1ual pre­ to environn1ental variation such as the cipitation over 600-650 tn1n; and Q. robur exposure to li ght, rainfall, kind of soil, L. and Q. lusitanica Latn. in the south of substrate, etc. Badajoz and north of Caceres in closed We realize that the classification we pro­ valleys of mountainous areas with higher pose is artificial and forced, because the annual rainfall (>900 1111nlyear). genus Quercus in the Iberian Peninsula Wind pollination between the differ­ has a very wide ecological range. 1t is ent species gives a series of hybrids that fotmd from 1500- 1300 m to sea level in all need taxonomic study in order to differ­ parts; consequently it is adapted to every entiate them from the stable taxa, and to tnicroclimate. In addition, as stated by E.F. detennine their origin. We have been Galiano in Flora Andalucia Occidental able to detect in the areas of n1ixing be­ (vol. 1, p. 160), "The genus Quercus shows tween encinares (Q. rotundifolia) and a very large variability in many of its char­ alcornocales (Q. suber), individuals with acters, particularly those of the leaves and a Ie a f co 1or s i 111 i 1ar to that of the fruits, because of the ease of introgres­ alcornoque, but with bark and floral char­ sive hyb1idization between several of the acters very sin1ilar to those of the encina. species." Because of this, evety one of There were also exatnples of cupule and the forms we have identified could be re­ acorn specitnens very sin1ilar to those of garded as a cross between different spe­ the alcornoque, even though their taste cies that occupy different localities. As a is sweet, and with bark and leaf color result of introgression between individu­ very sitnilar to the encina. Because of als, stnall differentiating characters in sotne this, we believe it was not appropriate to examples would not be true genetic vari­ study these individuals because we con­ ants, but would have been produced by sider them Q. suber L. x Q. rotund{folia crossing processes brought about by the Lam., (Q. xmorisii Borzi), commonly type of pollination (by wind) present in called "n1estos". this family. We also found son1e trees of Q. In this work we only n1ake reference to rotundifolia that had aborted (sterile) Q. rotund(folia Latn. In Extremadura, fe tnale flowers and n1ale flowers in large seven more species in the genus Quercus numbers, corresponding to Q. ballota f. are also found. These are Q. pyrenaica mascula Coltneiro & E. Boutelou. We Willd. in Caceres and son1e part~ of have not treated these as independent Badajoz; Q._faginea Lan1. in almost all the taxon because they have no progeny province; Q. canariensis Willd. in some mountainous parts of Badajoz and contd. on pg. 52

• No.ll I Fall 2000 Page 51 International Oaks

• rotundi Ill • • • contd. from pg . 51

and so do not have continuity. However, Desfontaines, R. L. 1798-1800. Flora these individuals could pollinate other Atlantica. II. trees, which would then be able to pro­ Font Quer, P. 1970. Diccionario de duce viable acorns, which in turn could Botanica. produce trees with the same character­ Laguna, M. 1870-72. Resumen de los istics. This would be the only way these trabajos de la Cotnision de la Flora For­ characters could be preserved, and with­ estal Espanola. out it, the oaks with aborted female flow­ Latnarck, J. 1783. Encyclopedie ers would not be able to reproduce. Methodique Botaniq ue. I. All of this demonstrates that there are Linnaeus, C. 1753 . Species P1antarurn. enormous opportunities for research in Maire, R. 1961. Flore deL' Afrique du Nord. Vol. Vll. 122-123. the Extremadura Region, with consider­ Palau Verdera, A., 1787. Parte Practica able economic implications. We consider de Botanica. it fundamental to maintain the present Pinto da Silva. 1943. Broteira. Vol. Xll research line and to also develop other (XXXIX). Fasc. II, 76-80. paraJlel areas of study on other variet­ Poiret, J.L.M .. 1811. Supplementum ies, fonns and existing hybrids. Encyclopedie. II. Saenz de Rivas, C. 1972. Biometria fo- References 1iar de un poblacion de Q. ilex L. en Bonnier, G., 1934. Flora complete de Monserrat (Barcelona). Anales Jard. Bot,. France, Suisse et Belgique. Vol. 10: 32-38. Madrid. 29: 39-58. Brotero, F. 1804. Flora Lusitanica. II. Schwarz, 0. 1964. Quercus L. In: T.G. Caballero, A. 1940. Flora Analitica de Tutin, VH. Heywood, N.A. Burgess, D.H. Espana. Valentine, S.M. Walters & D.A. Webb. Carvalho, E., Vascocellos, J. & E. Flora Europaea : 61-64. Cambridge Uni­ Amaral Franco, J. 1955. Carvalhos de Por­ versity Press. London. tugal. Anal. Do Inst. Sup. De Agronomia. Taborda de Morais, A.A.T. 1940. Bol. Colmeiro, M . & E. Boutelou. 1854. Soc. Brot. Ser 2, 14: 122. Examen de las encinas y den1aS arboles Valdes, Talavera & Galiano. 1987. Flora que producen bellotas. Vascular de Andalucia Occidental. Ed. De Candolle, A. 1864. Prodromus Ketres. Barcelona. systematis natural is regni vegetabilis. XVI, 2. Translation by Maricela Rodriguez and Allen Coombes International Oaks

a at e

by Philippe de Spoelberch Belgium

elgiu1n is a s1nall country, and these notes would prob­ ably apply to 1nost of the Netherlands and northern France. The tetnperature can vaty at any given time by 6°C between the western coast and the higher eastern region which reaches elevations of up to 600 m. Temperatures will rarely fall below -20°C, and only for a couple of days. But this will happen at least once in a decade. Otherwise, the prevailing west­ erly winds result in a typical marititne cli1nate. Frosts tnay start in late October and occur periodically until n1id May. These are often da1naging to oaks from the tnore continental climates of the world. There are only two indigenous Belgian oaks: Quercus robur and Q. petraea. The oak forests of Belgiun1 are concentrated along a narrow band in tnid Belgium at a lower altitude than the beech and conifer forests. There are 80,000 ha of tnixed decidu­ ous forests spread over that region, with various con1binations of Quercus spp., Fraxinus spp., Acerpseudop!atanus, etc. Oaks cotnmand the highest price for con1mercial timber. Between 1985 and 1991 , n1en1bers of the Belgian Dendrology Society conducted a survey ofren1arkable trees in approxitnately 800 parks, gardens, and arboreta in Belgiutn. A total of 13,500 trees were .measured and identified. The results of the work were

contd . on pg . 54

No.ll I Fall 2000 Page 53 International Oaks

• • • contd. from pg. 53 published in 1992 under the name Bomen the Systematic Arboretum at in Belgie I Arbres de Belgique. There­ Groenendaal. The more recent introduc­ sulting inventory includes 1,067 oaks tions are found in the collection at belonging to approximately 100 taxa. But Hemelrijk (established by Robert and more significantly, only 18 taxa were iden­ Jelena de Belder) which has 200 speci­ tified 111ore than ten times, 43 taxa were mens of83 taxa. There are also good oak found in only two to ten locations, and collections at Bokrijk, Herkenrode and 41 taxa were found only once in a single Mariemont. The most con1plete, albeit on location and rnost probably in one of very limited space, is without doubt the the spec i a Ii s t co ll e c t ions ( although collection established by Michel Decalut these were not intensely researched). at Arboretum Waasland. He has also Common beech (Fagus sylvatica) was developed a nursery, and his worldwide the most frequently encountered remark­ connections allow him to offer for sale a able tree in the 800 parks, and Quercus selection of approxitnately 250 taxa. robur was a distant second. More pre­ The following are results of a survey cisely, Q. robur was found in 322 loca­ of a number of successful oaks found in tions. It was followed by Q. rubra in 155 Belgi urn, representing taxa which even­ locations Q. robur f.jastigiata in 81 lo­ tually may be useful for future plantings cations Q. cerris in 57 locations, Q. in parks and gardens. Most of the mea­ palustris in 44 locations, Q. petraea in surements of girth (made at 1.5 tn height) 41 locations, Q. xturneri in 21 locations, date back to the 1985-1991 inventory and Q.. frain etto in 20 locations. period. Some of the trees 1nay have died Wild and cultivated plants originating or been cut without our know ledge since frotn Europe and introductions from then. A few measuren1ents may have 1 America have dominated the l9 h cen­ been updated since the original survey. tury plantations. Smaller oaks, which tnay Obviously, tnore recent introductions have been introduced from Asia in the have not been evaluated, and it n1ay be 20thcentury , remain very rare and limited possible that hardier origins 111ore to specialist collections. Several dendra­ adapted to our clitnate might justify the logical collections were established start­ inc Ius ion of further taxa into such a list ing at the end of the 19lh Century. The of those considered useful. most complete are without doubt the Geographical Arboretum at Tervuren and Q. acutiss ima was reported only twice,

Page 54 ' No.ll/ Fall 2000 International Oaks and the chan1pion tree ( 184 c 111 ) was October, well before our native oaks. found in the old botanical garden in On ly two plants of Q. aliena were Brussels. Unfortunately, it bas lost n1 any found. They are unhappy, suffering fre­ lower branches recently for lack of light. quently from the effect of spring frost. Tt is a n1 ost decorative and hardy spe­ Q. bicolor js a n1uch better plant here. cies, at least in tnid and low Belgiutn. This Approxin1ately 12 plants have been taxon should be planted n1 ore frequently. found. All are growing in lower (west­ Q. alba is a difficult plant to grow here, erly) Belgiu111. but where successful it can reach good Q. castane[folia has been reported six heights. Six significant trees were iden­ tin1es. This tree is also frequently datn­ tified; the best one (232 em in girth) is in aged by spring frost but it wiJI end up, if the Stadspark at Tienen. It has grown to isolated, as a beautifully forn1ed speci­ good size in a cratnped position between n1en. The chan1pion tree at Groenendaal other n1 ajor trees. Autun1n color is out­ has reached 246 c111 in girth. standing and these plants reall y deserve to be isolated on a lawn or open space to sho-vv offtheirpurple coloring earl y in contd. on pg. 56

¥ , r

Jt';Guy & Edi th St ernberg

Ct~)l Sternberg slanding 1rith the Gras Chene de l.iernu. u 1.000 yeor old Qucrt;US robur in Lienw. Belgium.

No. 11 I Fall 2000 Page 55' International Oaks

• • • contd. from pg. 55

Q. cerris is quite frequent in collec­ rare plant frotn the Iberian Peninsula tions. The girth of the largest specimen could be planted more frequently in spe­ is well above 400 em. This tree is found cialist collections. It is a hardy and el­ in most areas of Belgium with the excep­ egant tree, as demonstrated by the two tion of the very high altitudes. In the specimens that were discovered. Ardennes, it will frequently be damaged Q ..falcata is not hardy here, and only by frost and the stem will bear the marks one young plant has been identified in of such wounds. There are a number of specialist collections. cultivars in old landscape gardens. Q.frainetto is probably one of the bet­ These plants often have reverted to the ter exotic trees to plant in our parks and type on most of the crown, but the varia­ gardens; 20 remarkable trees were iden­ tions are still visible at the end of so1ne tified with five having girths of tnore than lateral shoots. Recently, a large tree (293 400cm. em) of Q. cerris 'Aureomarginata' was Q. xheterophylla has been found in identified, but the tree had reverted to seven old parks; it is a rare plant here, the type on more than 95 percent of its and all specimens have reached signifi­ crown. This cultivar was apparently not cant size. There are no young plants; it in cultivation anyn1ore. Specimens of Q. seems that it is not propagated much at cerris 'Laciniata' , 'Marmorata', the present time. The champion tree 'Pendula', and 'Argenteovariegata' have stands at 412 em. Most plants are in the been found in some of the parks. northern province of Antwerp; it is a Although Q. coccinea has been men­ good grower, as you would expect given tioned several times, one is never very its two parents (Q. phellos and Q. rubra). sure of its identification. It is my feeling Q. xhispanica (Q. suber x Q. cerris) is that Q. coccinea is not that hardy here, a very rare tree; only two trees of signifi­ and that many plants are stock of Q. cant size were found. However, there are palustris or possibly Q. palustris hy­ today tnany young plants in specialist brids. Q. coccinea ' Splendens' definitely collections. is not hardy; tnany young plants have Q. ilex is a rarity and not completely been tried, and died at an early age. hardy in Belgiutn. One plant of reason­ Plants of Q.faginea have been found, able size has survived in a park in Brus­ with two significant specimens (320 ctn sels and without doubt it enjoys the and 154 em) in northern Belgium. This benefit of the warm tnicroclimate of the international Oaks

city environment. is a surprisingly low nun1ber consider­ Q. in1bricaria is very much at hotne in ing the fact that this is an indigenous our Belgian parks and gardens. It grows plant. It nevertheless has reached sig­ to a significant size, and is similar to Q. nificant size, with a cha111pion at 692 cn1 pa/ustris in its shape and aspect. The (in the center of the country, at Dave). Belgian chan1pion is 332 c1n in girth and As would be expected for long-cultivated grows at the arboretum of the Agro­ species, there are several cultivars, with nonlic lnstitute at Getnbloux. ~Mespi lifoli a' the n1ost frequent, repre­ Q. xleana is 1nore colntnon than its sented by several trees well above 300 parent Q. i1nbricaria· significant plants ctn in girth. have been found, and one n1ay guess Q. phellos and its hybrids (particularly that tnost of these were grown as Q. Q. xschochiana) have been found in ilnbricaria seedlings, pollinated by Q. several parks and gardens in lowland velutina. Several trees are above 400 CI11 Belgiun1. It is not con1pletely hardy here in girth, with a cha1npion at 457 cn1. and suffers in our n1aritirne clin1ate from Q. n1acranthera was found in on ly one aututnn and spring frosts . Jt w i 1l soJne­ location. Young plants can be found in titnes hold on to its leaves well into Janu­ specialist collections. It is not hardy here ary. Thi s is especial ly the case on yo ung and frequently is datnaged by spring trees. The aututnn color is a little disap- frost. potnttng• • . Q. n1acrocarpa is a better plant here, Q. pubescens n1ight be indigenous in growing to significant size like Q. the southern warm hills in the region of pa/ustris. Several trees have reached 200 Chi n1ay, but I know of no spontaneous em in g irth~ they may be hybrids of other wild trees. A coupl e of big trees have oaks of the Quercus section. been found in a nun1ber of parks, with a Q. palustris has been fo und in close chan1pion at 435 c1n in the center of the to 50 locations, with at least 40 signifi­ country. This elegant oak should be used cant trees reaching sizes above 400 cn1 n1ore frequently in our parks. in girth. If they are well isolated fron1 an Q. fJyrenaica is a rare plant. Six good early age, they will withstand any storms; specin1ens were found tnostly in the

• but in forest plantations, when openings north of the country. A chan1pion tree at occur, they will fall over in the face of 310 ctn grows in the city of Liege, and is strong winds after reaching a certain probably the n1ost northerly plant of this height. They contribute significantly to species in Europe. The cu ltivar ' Pendula' the autun1n coloring of our parks and is found at least as frequently as the type. w"Oodland. Q. robur was found in close to half of Q. }Jetraea is our second indigenous oak tree. Retnarkable specin1ens were found in approxitnately 41 gardens. This contd. on pg. 58

No.ll I Fall 2000 . c Page 57 International Oaks

• • • contd. from pg. 57

the parks and gardens. The largest Bel­ in the n1any wood land areas and displac­ gian tree, at Liemu (985 em), is a very ing the existing vegetation. lt has be­ darnaged tree. It has lost most of its come a pest in several parks and can crown and is completely hollow. It is a actually destroy the woodland structure well-known tree, the object of many sto­ if care is not taken to eliminate the young ries and cults, and well looked after by a seedlings. Many of the largest trees are nutnber offolkJore societies. For this in­ greater than 500 em in girth, with a cham­ digenous oak, many cultivars have been pion of 672 ern. Q. rubra 'Aurea' con­ found, including 'Albomarmorata' ( 4 tributes significantly to spring color. The plants), 'Atropurpurea' (3 locations), golden coloring will ren1ain for several 'Cucullata' (9 locations), and '.Tortuosa' weeks, well into June and July, if there is ( 4 locations). The most frequent of the good growth and plenty of sun. selections is Q. robur f.jastigiata. There Q. xturneri is a favorite of many gar­ are clearly several forms of this oak and dens. It was found more than 20 times in it is the third 111ost frequently encoun­ many parks and botanical gardens. It is tered taxon in the Belgian parks and gar­ a spectacular evergreen tree, especially dens (81 locations). when planted as an isolated specitnen. Q. xrosacea, the hybrid between our The chatnpion plant has reached 285 ctn two indigenous oaks, is quite frequent in girth. It is obviously hardy here, and with 16 big trees found all over the coun­ is found all the way to the city of Lie'ge, try; the champion tree has reached 500 but of course not in the higher eleva­ em in girth. tions of the country. Q. rubra is the second most frequent Q. velutina has been found in approxi­ oak encountered. It shows rapid growth tnately 15 parks. It is often confused with and good adaptation to most of low and Q. rubra. It reaches significant girth ( 455 middle Belgium. Its autun1n color and em); the autumn color is somewhat rusty commercial value justify its presence· but red, surely less flamboyant than that of it also is an invasive plant, seeding itself Q. rub raJ but of a wam1er coloring.

EDITOR: This paper was presented at the 75th Anniversary Symposium of the Dutch Dendrology Society, Rotterdam. International Oaks

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• In this issue Oaks- • The Jour11al of the Jnterltational Oak Society c/o Doug McCreary- HaJ·dwood Mgt Ptvgt'Bm University ofCalifoJ·nia Remembering 8279 Scott Forbes Road Oak Tree Hybrids in the Browns Valley, California 95918 Bejah Forest USA The Great Oak of the Landis Arboretum

An Oak Wilt Primer

Oaks of the Chihuahuan Desert Region •

Quercus rotundijblia Lam.

I and its forms in • Extremadura, Spain

Oaks in Belgium: Text of a • Slide Presentation Made at the Arboretum Trompenburg, July 3, 1999

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