JULIUS O. BOOS, 1993 33 Experiencing Urospathas Julius o. Boos 1368 Scottsdale Road East West Palm Beach Florida 33417, USA In 1988 I visited Dewey Fisk in Miami. along the Tortuguero Canal in northeastern Among his magnificent collection of aroids Costa Rica by Fred Berry. was a specimen of Urospatha in flower, the The Central American species is Uros­ first of this genus I had seen. I immediately patha grandis Schott originally described fell in love with these plants. Although they in 1857 from a specimen collected in Pan­ lack the bright colors or dramatically pat­ ama. A review of this genus is badly needed, terned leaves of some other aroid genera especially in South America. Synonyms of such as Anthurium and Alocasia, Urospa­ U. grandis include U. tonduzii Engler de­ tha, with their magnificent, large sagittate scribed in 1885 from Costa Rica, and U. leaves with purple and green patterned pet­ tuerckheimiiEngler described in 1905 from ioles and elongated spathes in muted col­ Guatemala. Urospatha jriedrichsthalii ors of bronze and ivory elegantly twisted at Schott described in 1853 (and thus the old­ their tips, possess a somber beauty you may est name) from material collected in Nic­ find hard to ignore or resist. aragua, an illustration of which accompa­ As far as it is presently known, the genus nies the generic protologue (Schott, Fig. Urospatha is found only along the Carib­ 7) is in fact a Sagittaria (possibly S. mon­ bean coast of Central America and through­ tividenis Cham. & Schlect.) in the Alis­ out the tropical lowlands of eastern South mataceae, according to Hay (1992). America. It is a plant of swamps and wet The specimens of Urospatha growing in places, found along rivers and in partially both Dewey's and Dr. Birdsey's collections or seasonally wet savannahs, etc. This ne­ seemed healthy and were in flower, but due cessity for "wet feet" presented problems to the conditions under which they were for a potential grower, and my first attempt being grown I felt they had not reached with a tiny "pup" from Dewey's plant end­ their full potential as horticultural subjects. ed suddenly after a year of growth to 45 cm A search of the available literature turned tall, when this beautiful, seemingly healthy up little or no information on their cultural plant quickly wilted and died. After this requirements except for a comment that happened a year later to a second plant, the genus was not in cultivation. Aroid careful investigation showed that it was growers, when asked, made negative com­ probably caused by the large Bufo toads ments that they couldn't be maintained over soaking themselves during dry periods in a period of time as the necessity of growing the saucers of water in which my potted them with the pots in saucers of water caus­ plants stood and rapidly replacing the wa­ es the soil mix to quickly sour, thereby kill­ ter in the saucer with their too-strong urine. ing the plant. I now prevent this by placing lots of water­ In early 1990 I managed to purchase two filled saucers under my plant benches for small plants of U. sagittifolia (Rudge) Schott the toads to reach easily, as I value their collected in Venezuela in the Orinoco Del­ control of snails, slugs, etc. I change the ta in the State of Amacuro. I decided to try water for them during my regular plant potting these water-loving plants as fol­ checks. lows: I placed 10-15 cm of coarse gravel or I managed to replace these lost plants lava rock in the bottom of a suitably sized through the generosity of Dewey and Dr. plastic pot, usually between 1-5 gal. de­ Monroe Birdsey, both of whose mother pending on the size of the plant; I then plants originated from a collection made potted the plant on this bed of rock using 34 AROIDEANA, Vol. 16 Fig. 1. Urospatba grandis Schott . Tortu · Fig. 2. Urospatba sagittif olia ( Rudge) guero Ca nal, Lim on Province, Costa Ri ca. Schott. Orinoco De lta, Amacuro State, Ven­ Photo by Robert Skinner. ezuela. Photo by Robert Skinner. a mixture of approximately three·quarters for wind, as the plants have received some coarse "play" sand and one-quarter com­ damage from 60°F temperatures with wind. mercial soilless potting mix- the brand does I use a weak liqUid fertilizer weekly in not seem critical, followed by a layer of summer, monthly in winter. Dyna-Gro 7 -9- 5 approxim ately 1 cm of composted cow ma· seems to give the best results; there has nure. The potted plants were placed in large been some "leaf burn," particularly on U deep saucers containing water between 5- grandis, when I have tried other brands. 10 cm deep whi ch are refilled as necessary My growing experiments resulted in one of and changed and rinsed evelY 2-4 weeks my plants of U sagittifolia receiving the first to prevent a bui ld -up of fertilizer sa lts due place Division Award atthe 1991 l.A.S. Show to evaporati on. I am still experimenting us­ in Miami. ing different combinations in my potting An interesting problem that occurred was mixes. that during the surge of rapid growth in I grow my Urospathas on benches in the early summer, the leaves of U sagittzjolia parti al shade of fru it trees in my yard, using were emerging from the plant with one or the north side of my house from March to both of their rear lobes missing, seemingly October, when these heat-lOVing plants re­ torn off during rapid growth in their em­ ally thrive in summer temperatures that blyonic stage wi thin the plant. This dev· reach 90°F during the day and 80°F at night. astating problem which ruins the beauty of I then move them to the south side of my these spectacular leaves seems to have been house from late October to early March for corrected, thanks to a suggestion by Craig protection from the cold north winds. If the Morell, by sprinkling about Yz to 1 tea­ temperature is forecast to fall below 55°F , spoonful of manganese sulfate on top of I bring them into my garage. I am also alert the soil. This apparently toughens the leaf JULIUS O. BOOS, 1993 35 texture, and has drastically lessened the in­ its sides leaving the "cap" intact and the cidence of missing posterior lobes. seeds to float encased in gelatin. The seeds The inflorescences of U. sagittifolia dur­ are collected and placed in a large strainer ing daylight hours emit an intense pleasant where a strong jet of water separates them odor of exotic tropical fruit. U. grandisemits from the gelatin and any bits of pulp. I do a not unpleasant faint odor of fresh canta­ a final soak of the seeds in a bowl of water loupe or old dried fruit. These odors attract containing a few drops of household bleach fruit flies and various small beetles and as an anti-fungal measure, then place them wasps which may be the pollinators. on top of 4-5 cm of very wet sand in a deep­ The spadix is bisexual. The female parts sided tray which I enclose in a clear plastic are receptive as the spathe opens and re­ bag. The tray is placed under fluorescent main so for about a week; the circular stig­ Gro-Lux bulbs or can be placed in a sunny mas are visibly moist and sticky during this greenhouse under the shade cloth. stage. Soon afterwards, the spadix begins The seeds begin to germinate starting at to produce visible amounts of powdery around 4 weeks. When the seedlings are cream-colored pollen, starting at the top around 3-4 cm tall, they are transplanted and gradually moving downward for a pe­ to small pots or a communal tray with about riod of approximately 10 days. If you are 4 cm of coarse gravel in the bottom and a fortunate to have one plant in flower at the mixture of sphagnum moss and a little female receptive stage, and another plant coarse sand on top. The pots or trays are whose inflorescence is producing pollen, placed in other trays containing 3 cm of it is a simple matter to transfer pollen from water. I fertilize every two weeks with a one to the moist stigmas of the other, using weak solution of Dyna-Gro 7-9-5. Whitefly a slim paintbrush moistened in water. and aphids can be occasional problems to If not pollinated, the inflorescence of a the seedlings, but they can be controlled healthy, mature plant will still develop a by Safer soap or insecticidal sprays as need­ few fruits on the spadix. These fruits will ed. The seedlings grow rapidly and reach each contain from 2 to 8 large kidney­ 15 cm tall within 6 months. One of my seed­ shaped warty seeds. If the inflorescence is lings produced its first inflorescence in 14 pollinated, most of the fruits on the spadix months from seed. slowly mature within six months and can I have seedlings produced from U. gran­ produce up to 335 viable seeds from one dispollinated by U. sagittifolia, from U. sag­ inflorescence. As the fruit develops on the ittifolia pollinated by u. grandis, and from spadix, it becomes larger and heavier with­ wild collected seed of U. sagittifolia ex: in the persistent spathe, causing the entire French Guiana. The seedlings produced by inflorescence to slowly bend over at the top the pollination of U.