428 FLORIDA STATE HORTICULTURAL SOCIETY, 1961

Table III. The effects of fumigants andon varieties the weight (lbs,) of conns produced per 100 ft, of row in 1960.

Varieties White Elizabeth Spic & Florida Fumigant

Fumigants Excelsior the Queen SpanFriendship Pink Means Mylone 23.5 38.1 35.4 41.6 47.7 37.3 38.1 Vapam 26.7 32.9 41.2 40.1 49.7 Check 18.5 30.8 30.8 35.7 41.2 31.4 Variety 46.2 means 22.9 33.9 35.8 39.1

L.S.D 0.05 0.01 Between fumigant means 3.9 5.9 Between variety means 3.7 4.9

The failure of the fumigated plots to Either 75 gallons per acre of Vapam or 300 produce more corms than the untreated plots pounds of active Mylone applied two weeks in 1960 is believed to have resulted in part prior to planting is recommended for the from the fact that the untreated plots were production of cormels on sandy soils of Florida. kept relatively weed free throughout the LITERATURE CITED growing season by hoeing. During the two pre 1. Burgis, D. S. and A. J. Overman, 1956. Crop produc vious seasons, the untreated plots became tion in soil fumigated with crag mylone as affected by heavily infested with Bermuda grass and weeds rates, application methods and planting dates. Proc. Fla. State Hort. Soc. 69:207-210. in the latter part of the season. The beneficial 2. Burgis, D. S. and A. J. Overman, 1957. Chemicals effects of the fumigants during 1960 are re which act as combination herbicides, nematicides and soil fungicides: I. Effect on field-seeded tomatoes. Proc. Fla. flected in increased corm weights. State Hort. Soc. 70:137-139. 3. Burgis, D. S. and A. J. Overman, 1959. Vapam and As far as nematicidal action is concerned, VPM soil fumigant must be applied properly to be effective. all fumigants usedduring the three-year Proc. Fla. StateHort. Soc. 72: 112-114. 4. Christie, J. R. and V. G. Perry, 1951. Removing nema period were highly satisfactory. todes from soil. Proc. Helm. Soc. Washington 18:106-108. 5. Fred, E. B. and S. A. Waksman, 1928. Laboratory Summary and Conclusion manual of General Microbiology, p.13. 6. Magie, R. O. 1956. Gladiolus Stromatinia disease con The usefulness of Vapam and Mylone in the trolled by soil treatments and cultural methods. Phytopath production of gladiolus corms from cormels ology 46:19. 7. AAagie, R. O., 1957. Soil fumigation in controlling was investigated. Vapam at the rateof 75 gal gladiolus Stromatinia disease. Proc. Fla. State Hort. Soc. lons per acre or Mylone at the rateof 300 70:373-379. , , 8. AAagie, R. O. 1958. AAylone controls gladiolus dry rot pounds active per acre was effective in control disease. Station to Station Research News. Union Carbide Chemical Company 4:1-2. . ling weeds, nematodes, and soil-borne fungi. 9. Overman, A. J. and D. S. Burgis, 1957. Chemicals Corm production was increased markedly by which act as combination herbicides, nematicides and soil fungicides: II. Effect on soil microorganisms. Proc. Fla. the use of either fumigant. State Hort. Soc. 70:139-143.

THE GENUS PLATYCERIUM

James Floyde Griffin, jr. and keras, meaning horn. It is ideally des criptive for the reason that the plants exhibit Executive Secretary fronds which are promptly reminiscent of ant

Florida Nurserymen & Growers Association, Inc. lers. The Platycerium comprise a small group of 79 Harbor Plaza plants of rather widely scattered habitat Key Biscayne throughout thesub-tropical and tropical regions

The botanical name, derived from the of the world. Some are found in temperate Greek, is compounded of platy, meaning broad, Australia, others in the Malay archipelago, the GRIFFIN: PLATYCERIUM 429

Philippines, Africa and one species is found in Neuroplatyceros Plukenet was a pre-Linnaean the South American Andes. The genus is name of Platycerium alcicorne, cited as a syn- readily recognized by the repeatedly forked nonym, even in binomial form as N. ethiopicus, character of the fertile or spore bearing fronds. by many writers, and taken up by Fee, as a These plants produce both fertile and in matter of justice, in avowed violation of rules fertile fronds, each type of a distinctly different, already recognized. » but harmonious structure. The fertile fronds Alcicorne (bifurcatum) are usually antler-like, and carry the spores in patches, usually on the underside of the leaf Al-cic-orn-e (Elk's Horn) extremity. The barren or basal fronds tend Found in Tropical Australia, Java and the to be rounded, shield-like and usually grow in East Indies. It was introduced to the Royal symmetrical, opposite pairs, pressed back flatly Botanical Gardens at Kew in 1808. Basal fronds convex against the growing media, and con are rounded, ascending, curving outward, con forming to the container shape. These persis vex, with edges waved and lobes spreading, and tent basal fronds or scales gradually fade from are downy when young. The fertile fronds are their original green, becoming brown and 2 feet to 3 feet long, bright green, clustered, overlapping. They protect a mass of stems and of somewhat upright habit, twice or three times roots, and collect a composting debris which forked, and of a thick, leathery texture; their helps to nourish the plant. From a point where strap-shaped and bluntish ultimate divisions these leaves intersect, somewhat tangentially, have the sporangia located in the last forks and the fertile fronds arise and arch out. at their base in very irregular patches, and the Besides the unique mode of growth of these under-surface is covered with a thin cottony ferns, their distinguishing character resides in down; upper-surface covered with a dense stel the location of the sori (spore masses), which late (star-shaped) pubescence. form large patches on the lower surface of the This species is one of the more robust growers, fertile fronds, and are in most cases situated easily propagated from the young plants pro at their extremity, which they cover to the duced on the roots. length of sometimes as much as 8 inches. The fertile fronds are in all cases, as regards shape, Alcicorne majus size and texture, thoroughly different from the Al-cic-orn-e ma-jus (larger) barren ones, which are of a peculiar rounded Found in Australia and the Malayan Penin shape, convex, and of a rather thick, parchment- sula. like texture. Basal fronds are roundish, convex and over In support of the contention that this fern lapping. Fertile Fronds are broadly lobed, borne has a heritage of great antiquity, fossilized on stiff flat stalks, rich green in color and spores have been identified in sandstone of the seldom divided more than once. These fronds cretaceous period, which would indicate this tend to be erect, with the broad forking lobes plant family has an age of about a hundred elegantly pendulous. Sporangia located at tips million years. of frond lobes. Platycerium is an isolated genus, raised to Much more robust than P. alcicorne with family status by Ching. There is some suggestion larger foliage. of relationship to Dipteris, Cheinopleuria and Andinum Christiopteris; but it is not intimate. There is more evident resemblance to Pyrrosia. An-di-num Alcicornium was proposed by Gaudichaud Found in E. Peru and E. Bolivia. First de as the name of a genus which would be recog scribed by J. G. Baker (annals of Botany, Vol. nized after further study. Its publication was 5, p. 496, 1891). Collected by Richard Spruce explicitly tentative. Approximately one year in E. Peru and by Pearce from Paquichas in E. later, Platycerium was properly published, and Bolivia, 1857. Gaudichaud accepted the name. Except as Basal fronds like P. alcicorne but much Underwood, (1899) and Bull Torry Club 32 larger, 2 feet to 3 feet long. Fertile fronds 6 feet (1905) 587, undertook to revive Alcicornium, to 10 feet long, very pendulous, with long it has been recognized properly as an abortive ribbonlike lobes, and sporangia located at third publication. fork back. 430 FLORIDA STATE HORTICULTURAL SOCIETY, 1961

The only known Platycerium from the differentiation, on the underside of the leaf) western hemisphere. Wilhelm Miller et R. C. were called. In Copelands' Philippine Book, Benedict, in Bailey's Cyclopedia of Horticulture there is only one picture, a full, front page states, "the type specimen was collected by photograph of Platycerium biforme, of a plant Spruce in the Andes of Peru, approximately in Manila, the fronds at least 15 feet long. 1857 and anyone who has ever read Spruce's Ellisii book, on his ten year's travel in northern South Ellis-ii America, with travel almost entirely by water, the inhabitants few and far between, a half- Found in Madagascar. Named by Sir Joseph savage mixture of Indians, Portuguese, Spanish D. Hooker for Rev. W. Ellis of Madagascar and negroes, with Indians predominating, can and described by J. G. Baker (Journal Linnaean not conceive of any plants having been intro Society of London, Vol. 15, P. 421, 1876, who duced as has been suggested by Copeland." said: "It has shallowly forked, narrow, deltoid Angolense (elephantotis) fronds—green on both surfaces, sporangial area Found in Upper Congo-land, Angola, tropical extending from edge to edge through the upper Africa. Described by Dr. Welwitsch. Discovered quarter." (Illustrated in Hooker's "Icones" in 1855. vol. 16), Basal fronds ascending, large, stiffly erect, hav Ellisii diversifolium ing a purplish veining and wavy crest providing a very majestic appearance. Fertile fronds Graf in Hortus states: "Dwarf epiphyte at broadly wedge-shaped in outline with corners tractive because of the erect habit of its fronds rounded and merely wavy at the margin, nine which are broadly spreading into twice-divided, inches or more across the top. There are pendant lobes, covered with whitish stellate neither forks nor horns. The species is the hairs; basal fronds reniform, neatly covering only one bearing no resemblance to antlers. the fibrous roots.

The sporangia cover a patch nearly as broad as Grande the blade of the frond. It is also distinct by Gran-de (large) reason of a felt-like covering of rust colored wool on the underside of the foliage. The Found in North Australia, Malayan Islands and the Philippine Islands. Described by J. fertile fronds attain a length of 18 inches. Smith. Discovered in 1828 and introduced into Biforme (Coronarium) Royal Botanical Gardens at Kew by Bidwill in Bif-or-me (of two forms) Cor-o-nar-i-um 1842. Found in Burma, Singapore, the Malayan Basal fronds are very large, stalkless, nearly Peninsula and Islands, Java, Borneo, Philippines round, ascending, having their upper portion and Siam. Described by Blume. Discovered in divided into a number of broad, blunt segments of a spongy texture and pale green in color, 1842. Basal fronds overlapping, very thick, espe covered when young with a light, woolly cially towards the base, very tall and margin ir pubescence, which gradually disappears as the regular lobed. The normal frond is fresh green, frond becomes mature. Basal fronds are 24 pendulous to 15 feet in length, several times to 30 inches in length. The upper lobes are widely forked and the lobes gracefully twisted; doubly forked and staghorn-like with dark vena spore is curiously borne on a separate fertile tion. The fertile fronds, 2 to 3 feet long, pen reniform (kidney-shaped) appendage, 6 to 8 dulous, usually produced in pairs, and provided inches long and 3 to 4 inches broad, outer edge with a broadly wedge-shaped disk. This be rounded and entire. comes completely covered with sporangia which The basal fronds excite immediate recognition. forms a large triangular patch, and it bears at In his "Polypodiaceae of the Philippine Is each corner a repeatedly forked division, ex lands," 1905, Copeland gives the description of tending a good distance beyond it, but always P. biforme, but in "Genera Filicum," he calls remaining barren. The spores are borne against this P. coronarium, but the name biforme has the upper edge of the sinus (apex of the fork). priority, though as "Acrostichum biforme," 1801, This fern is the most majestic of all the by which name all genera with acrostichoid Platyceriums. No other fern forms such enor sori (having the sporangia in masses without mous and magnificent leaf masses. Unfortunate- GRIFFIN: PLATYCERIUM

ly this is the only species that does not produce hairs), sporangia V-shaped at tips. suckers at the roots, by which all the others are The fern is said to be a cross between P. easily propagated. It alone must be raised veitchii, described in Exotica by Graf. from spores. This species is said to be sensitive to excessive Madagascariense moisture. Mad-a-gas-car-ien-se Found in Madagascar. Described by Baker Hillii in Journal Linnaean Society, vol. 15, p. 421, Hillii 1876. Found in Queensland, Australia. Described Basal fronds rounded, deeply quilted with a by Moore. Discovered in 1877. network of bluish veins raised high and forming Basal fronds rounded, convex, wavy margined, elevated ridges. Fertile frond deltoid, about ascending, veins conspicuous. The fertile fronds 12 inches long and nearly as broad, narrowed 18-20 inches long, rigidly erect, unbranched por gradually from top to base, irregularly lobed tion long, forks numerous and compact, seg along the upper margin, the numerous divisions ments short and acute. Fronds clustered, cover all shallow and irregular in shape. Sporangia ed when mature with white, stellate (star- extending over the whole of the upper two shaped) hairs. Sporangia in oval, roundish thirds of the leaf blade, extending almost to the masses, near the base of the last segments but edges at the sides, but not quite to the tips not at the base of the sinus (recess) or about of the segments at the upper border. Texture an equal distance from the apex (tip) if there rigidly coriaceous (leathery). Upper surface is no side lobe. The upper third of the fertile bright green, lower surface in the barren area leaf is fan-shaped, dark green, 15 to 18 inches covered with a thin coat of white tomentum across, 3-parted, the central segments with one (woolly matting). or two side lobes near the apex (tip), the two lateral segments broader and twice or three Ridleyii times forked into 5 to 10 ultimate lobes. Rid-ley-ii This very handsome fern is said to be very Found in Malayan Islands. Described by closely related to P. alcicorne var. majus—so Christ, in Annals Buitenzong, Supplement II, much so, that until the plants attain their Vol. 8, plate 2, 1909. full development, it is very difficult to dis It is said to be separated from P. coronarium tinguish one from the other. The decided dark and others by the lower side of the fertile seg green color of the plant is one remarkable ment tips "protected" by the folding back of feature, the Platycerium being usually of a the segment margin. grayish hue, from the abundant white, stellate Pertaining to the above, Dr. George H. M. scales spread over their surface. Lawrence, Director of the L. H. Bailey Hor- The most distinctive character or at least the torium states, "I've never seen this condition one by which P. Hillii can best be distinguished (or the species) and am somewhat perplexed." from P. alcicorne var. ma jus is the repeated forking of the divisions of the frond. The over SUMBAWENSE all habit of growth is also much more rigid, Sum-ba-wens-e its fertile fronds showing no inclination what Found in Sumbawa, Indonesia. Described by ever to become pendulous. The sporangia, as Christ, in his book Farnkreuter du Erde, p 125 in P. alcicorne and its variety majus is absolutely 1897. limited to the extremities of the ultimate divi Straszewski, in his monograph, says it is sions of the frond. similar to P. bifurcatum (P. alcicorne) and P. Hillii, but differs from both in the fertile fronds Lemoinei (veitchii X willinckii) carried stiffly like antlers and not hanging, and Le-moine-i that the segments extend very deeply towards Basal fronds distinctly reniform (kidney- the base of the fertile frond. The color of the shaped) , developing occasional erect lobes. fertile frond is said to be gray-green, and the Fertile fronds, gray green in color, very slender, tips are always rounded (not acute or bluntly erect spreading, later pendant, twice forked, so). very narrow in all parts, both sides densely Graf in Exotica 2, states P. sumbawense white tomentose (covered with matted wavy (Sunda Isl.), smaller than alcicorne, basal FLORIDA STATE HORTICULTURAL SOCIETY, 1961 432 fronds forked, the irregular fertile fronds to- Fertile fronds growing in tufts (up to 11 in a mentose (hairy) pendent, and deeply forked cluster), narrow at the base tapering gradually two or three times into narrow divisions with to approximately 5 inches in width, then divid short patches of sporangia on the thickened ing into 6 to 8 narrow lobes all producing sporangia in irregular areas at tips, upper sur last forks. face grayish green from the quantities of stel Stemmaria (Aethiopicum) late (star-shaped) hairs which soon loosen and Stem-mar-ia Aeth-i-op-ic-um fall away; under surface whitish pubescent. Found on the Guinea Coast and Angola in West Africa. Described by Hooker and dis Wallichii covered in 1822. It was introduced to the Wal-lich-ii Royal Botanical Garden at Kew in 1848. Found on the Malayan Peninsula and on the Basal fronds, stalkless, rounded, convex, as banks of the Irawady in India. Described by cending and downy when young, edges cleft Hooker, 1860. into spreading lobes. The fertile fronds 2 feet Basal fronds, like those of P. grande3 are to 3 feet long, clustered, pendent, grayish deeply lobed, and their forked divisions are green in color, leathery, prominently ribbed and equally inflexed. Fertile fronds are also usually twice divided; their disk (widest unbranched produced in pairs and pendent, but the wedge- portion of the fertile frond) and first division shaped disk, which is located between the two are broader than in most other kinds, the patch divisions, has a rounded upper edge, and of sporangia (fruiting bodies) surrounding the forms a semi-circular projection, upon which sinus (depression) between the two horn-like may be seen two sporangial (spore bearing) projections, and passing into the fork so as to patches 3 to 4 inches broad, and from each side be shaped like the letter V. The under-surface of the projection is produced a division which of the fertile frond is covered with a thin, dense, is only once forked. These fronds are coriaceous silvery-white, cottony down. Veins repeatedly (leathery) with the under side covered by a forked and distantly anastomosing (running to yellowish pubescence. gether) ; venules (veinlets) internal and com- This beautiful and very rare species is said to poundly reticulated (netted). be closely related to P. grande. This species is particularly sensitive and should be watched closely during cool periods Wandae for indications of excess moisture. It is readily Wan-dae damaged by temperatures below 40 degrees Found in New Guinea. Described by Raci- F., especially if subjected to strong winds. bonski in Bulletin International, Akademija, Umiejetnosci, Krakow, p. 58, 1902. Strasgewski Vassei notes that its fertile fronds do not hang pen- Vasse-i dantly, are each twice forked, not hairy, each Found in Mozambique. Received at Royal segment wedge-shaped (basally tapering), the Botanical Gardens, Kew, 1908 from Jardin margins undulate (wavy). He contrasted it Botanique, Paris. Described from Kew Bulletin, with P. veitchii and P. Willinckii, noting that Appendix 111, p. 107-108, 1911. in P. veitchii the fertile fronds do hang pen- Basal fronds smooth, closely appressed (cling dantly, are thickly covered with minute hairs ing) to the support of the plant, oval, convex in and that the entire plant is very small; P. Wil- front, not cut into lobes, veins slightly promi linckii /ias flabellate (fan shaped) segments as nent. Fertile fronds tufted, regularly divided in P. wandae but they do hang pendantly, and into two's. are generally many times forked. Veitchii Veitch-ii Wilhelminae-Reginae Found in Australia. Introduced from Adel Wil-hel-min-ae Re-gin-ae Described by A. van Rosenburgh in Bulletin aide, Australia by Messrs. Veitch, for whom the species is named and publicly exhibited in du Department de 1' Agriculture aux Index 1896. Described at the Royal Botanical Garden, Neerlandaises, no. 18, pp 24-25, 1908. Fertile fronds limp, leathery, abundantly Kew, September 1905. Basal fronds appressed (clinging tightly to stellate-hairy, forked, the segments pendulous, 50 to 80 inches long, lanceolate (narrowly support), soon becoming brownish. SHEEHAN: FLASHLIGHTING CHRYSANTHEMUMS 433

wedge-shaped). The sterile fronds are 30 to 40 valid references include: diforme, divergens, ir- inches long, erect, the upper parts deeply lobed riodes, mayii, pumila and velutinum. and the lobes forked. REFERENCES Willinckii I. DeLaMare, A. L, Jan. 27, 1894, American Gardening- a Journal of Horticulture-vol XV #7 p. Ill Will-inck-ii 2 Taplin, W. H. and F. L. Atkins, Platycerium, The Stan- da™ Cyclopedia of Horticulture, L. H. Bailey, Vol III, p. Found in Java. Described by Thomas Moore 2/08. 3. Dallas, John, Some Greenhouse Ferns. in 1875. 4. Bailey, L. H., Platycerium, The Manual of Cultivated Plants, revised edition, p. 80. Basal fronds tall, stiffly erect, prominent 5. Copeland, Edward Bingham, 1947, Platycerium, Genera rilicum. lobes deeply cleft, roundish and overlapping. 6. Schneider, George, 1905, Choice Ferns for Amateurs. The fertile fronds, produced in three's, arise 7. Nicholson, George, Platycerium, The Illustrated Dic tionary of Gardening. from the growing point located in a notch in 8. Nehrling, Henry, My Garden in Florida, Vol. 2. TL9- Broad Horn Ferns or Platyceriums, December 12, 1891, the side of the round, close-fitting, base of the The Gardener's Chronicle, p. 697. sterile stem, erect at first, then falling straight • |1°>Yv1y.r,S.eryTu^

FLASHLIGHTING CHRYSANTHEMUMS

T. J. SHEEHAN 2 seconds per minute (spm) for 4 hours (10 P.M.-2 A.M.) had the same effect as 4 hours Florida Agricultural Experiment Station of continuous light. However, he found that all Gainesville varieties did not respond to this treatment. Waxman (3) working along similar lines stated The possibility of using 'flash' or 'cyclic' light that a minimum flash of 4 spm for 4 hours was ing in chrysanthemum production has been required to prevent flower bud initiation. suggested by several workers (1, 2, and 3). Waxman used a minimum of 20 foot candles in Preliminary results, although quite variable, in his work. 'Cyclic' lighting, using 10 to 30 dicate that some method of 'flashlighting' is minute cycles for 4 hours, is recommended by feasible. A practical method of 'flashlighting' Cathey (1), who suggests that when using 20 would greatly reduce lighting cost and thus foot candles of light, plants need be lighted be of economic importance to chrysanthemum only 5% of the cycle, or a 30 second flash for growers. 10 minute cycles and a 1.5 minute flash for 30 Langhans (2) reported that 'flashlighting' for minute cycles. Consequently growers reading literature are at a loss as to which method Florida Agricultural Experiment Station Journal Series No. 1374. should be used.