Selbyana 27(1): 88-92. 2006.

HORTI SELBYANI

PURSUING A PURPLE P ASSION-: A PERSPECTIVE FROM GREENHOUSE AND FIELD

HARRY ZELENKO P.O. Box 17-22-20043, Cumbaya, Quito, Ecuador. Email: [email protected]

When considering Caucaea olivaceum (for­ Trade in Endangered Species of Wild Fauna and merly known as cucullatum), the Flora) permit. My application was refused by the question arises, are there the many species sug­ CITES officer in Ecuador, but I will appeal the gested by John Stacy (1975) and echoed by Eric decision. Oddly, cut flowers can be taken across Christenson (2000), or do only a few species international borders without a problem. exist with many geographic varieties? If you DNA sequence analysis by Norris Williams, think I know either as fact, I do not, but I tend Mark Whitten, and Mark W. Chase (2001) has toward a few species. demonstrated that Caucaea does not differ ge­ Based on the 15 years I have spent collecting, netically from other species in the Cucullatum growing, studying, and illustrating Caucaea section of Oncidium. Since Caucaea is the older and their flowers from many areas of Co­ name, it has priority. lombia, Ecuador, and Peru, I am familiar with Although Lindley described and named On­ Caucaea olivaceum plants and their remarkably cidium cucullatum in 1838, an older name for beautiful flowers in all hues of purple-a color this species, Oncidium olivaceum, was published beloved since my childhood. These diverse col­ by Kunth in 1816 for a collected by Hum­ ors suggest to me that the plants might very well boldt and Bonpland. be a singular species with varieties. As a grower, I suspect that the genus is lim­ Not being a taxonomist, I am bothered by the ited to no more than the seven species listed be­ number of named species based on minor dif­ low. It is possible that more species will be dis­ ferences. I have been informed that the lip callus covered and described in the future, and it is also is not a definitive feature in defining a species possible (even probable) that with molecular (M.W. Chase pers. comm.). Although the callus studies, we might learn that some of the plants can be different in Caucaea olivaceum flowers that are today called species will turn out to be in Colombia and Ecuador, and the color, size, geographic varieties. and form can vary from plant to plant in differ­ • Caucaea radiata (Lindl.) Mansfield is a rather ent locations, they share undeniably similar small plant with diminutive white and brown characteristics (FIGURE 1). flowers. Found in Colombia at 2400 m, it is DNA analysis may provide the answer. Since a cool-growing epiphyte that blooms in spring the laboratory equipment needed for DNA anal­ and early summer. ysis of Caucaea is available at the 10drell Lab­ • Caucaea olivaceum (Kunth) N.H. Williams & oratory, Royal Botanic Gardens, Kew, I placed M.W.Chase, synonym C. cucullata (Lindl.) 14 different Caucaea specimens (flowers or leaf N.H.Williams & M.W.Chase, is a widespread parts) in sealed bottles with silica gel and ap­ group of populations that occur primarily in plied for a CITES (Convention on International Colombia and Ecuador. Having had so many

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FIGURE 1. Paintings of Caucaea flowers by Harry Zelenka from Orchids: The Pictorial Encyclopedia of Oncidium (Zelenka et al. 1997).

specimens in cultivation from different loca­ in Colombia." He gave species status to On­ tions over the years, and despite their differ­ cidium olivaceum var. gigantium but then ences in color, pattern, size, fonn, and callus, qualified it, stating that when more informa­ it is my opinion that, for the most part, they tion becomes available "It may prove to be a are simply varieties. In his monograph, Stacy distinct species." On the basis of callus dif­ (1975) listed Oncidium olivaceum as a syno­ ferences and flower part measurements, he nym to O. cucullatum subvar. olivaceum has given species status to Oncidium kenne­ based on a slight dimensional difference of dyi, O. cucullatum var. dolabratum, O. cucul­ the callus, noting that he had "not seen any latum var. macrochilum, and O. rhodostictum. material of this species outside the Cauca area At the time that Stacy visited Ecuador and 90 SELBYANA Volume 27(1) 2006

FIGURE 2. A large flower drawn to the size it was found in the field. When the plant was brought into cultivation, a smaller flower opened on a secondary inflorescence on the same spike. This flower, about half the size of the original flower, is sometimes called "Oncidium kennedyi."

Colombia to research his 1975 monograph, very also occurs in Venezuela. Caucaea mimetica few roads existed, compared with today. New has a different shape and callus from those of roads now provide access to previously unex­ C. olivaceum. Again, defining the difference plored areas, and new populations of Caucaea by callus alone may not be valid. Flowers of have been and are, even now, being discovered. C. mimetica, however, seem to differ in shape Cultural conditions vary from valley to valley from C. olivaceum. The callus structure ap­ and mountain to mountain; and when a popula­ pears to be similar to C. sanguinolenta. We tion is isolated over many generations, details of know with other orchids that flower shape can the flowers can vary from population to popu­ vary from population to population within a lation. With the lip callus not a definitive ele­ singular species, and thus the question arises ment in determining a species, we all know that about C. mimetica as well. DNA analysis flowers can vary in dimension from plant to might meld them into one species, or else de­ plant and even on the same inflorescence (FIG­ fine the difference between them. URE 2). e Caucaea nubigena (Lind!.) N.H.Williams & • Caucaea sanguinolenta (Lind!.) N.H.Williams M.W.Chase is primarily from Ecuador. It has & M.W.Chase is a species from Colombia and widespread populations and has been given a perhaps Ecuador with colors that range from number of different species names. All of the white with pale pink spotting on the lip to a populations I have observed, however, seem deep rose/magenta with purplish spotting. The to me to be a single species, though they are method of inflorescence of these plants differs extremely variable in color and shape, not un­ from that of Caucaea olivaceum in that the like C. phalaenopsis. Stacy gives measure­ flowers emerge from an undeveloped new ments of flower components, yet, as noted growth, while C. olivaceum flowers emerge above, every grower knows that dimensions from a mature pseudobulb. Stacy, however, of flowers and their petals and lips can vary had a limited view of populations in the field within any species of orchid. I therefore sug­ and had not grown either plant. Although their gest that what Stacy calls C. alticola, C. tar­ calluses vary, it remains to be seen if the two quiense, C. aequinoctiale, C. erosilabium, and are different genetically. C. chimborazoense should be treated as syn­ • Caucaea mimetica (Stacy) N.H.Williams & onyms of C. nubigena-geographic varieties M.W.Chase is a species from Colombia that again. HORTI SELBYANI 91

• Caucaea phalaenopsis (Linden & Rchb. f.) florescence; and when plants are moved to a new N.H.Williams & M.W.Chase from Peru and environment, emerging flowers may also change southern Ecuador is an extremely variable in size because cultivated plants obviously do species, exhibiting variation in shape, lip size, not receive the same conditions that nature pro­ color, and pattern from flower to flower. This vides. Some of the Caucaea plants I currently species includes unusual and distinctive color am growing from high elevations produce small­ forms, including some with chartreuse sepals er flowers when moved into our greenhouse. Ul­ and petals, pink lips, and no spotted pattern. tra-violet deprivation caused by the plastic roof­ Most of the flowers I have seen, however, ing may be the reason, even though the plants have purple and/or magenta spotting on the get better general care in cultivation than in the tepals and lip. Just because flowers from dif­ field. We have moved some of the plants out-of­ ferent areas (or different trees) have different doors and are waiting to see whether the flowers markings, and no two are exactly alike, we will be larger, as they were when these Caucaea cannot put species names on the hundreds plants were collected. (perhaps thousands) of color and pattern var­ The question remains; how does one define a iations. In his monograph, Stacy (1975) notes species? If flowers in a popUlation have varied in the botanical key to species that Oncidium colors, shapes, patterns, callus sizes, and fra­ dayanum and O. spathulatum differ from O. grances, and if the inflorescences vary, what phalaenopsis with suggested differences in then is the definable difference? Christenson their calluses. With other taxonomists holding (2000) has quoted much of Stacy's monograph that the callus is not a defining characteristic with little original and states that Cau­ in itself insofar as distinguishing a species, I caea are all small plants. I am growing Caucaea doubt Stacy's contention. With other growers olivaceum plants with pseudobulbs measuring in Ecuador, I believe that what Stacy listed as nearly 5 inches in height with leaves nearly a O. dayanum and O. spathulatum are simply foot in length. synonyms of C. phalaenopsis. Stacy has in­ According to Christenson, the callus, along cluded O. tripterygium in his lexicon of spe­ with the number of leaves to the pseudobulb, the cies, although he admits only seeing a single dimensions of the lip, the color schemes of the pressed flower "in a rather poor state of pres­ flower, and the overall measurements of the flo­ ervation, " again claiming the callus differs ral segments are the elements. Not being a tax­ from O. phalaenopsis. onomist, it is difficult for me to refute his list of • Caucaea andigena (Lindl.) N.H.Williams & criteria; but having spent time in the field and M.W.Chase is a small yellow-flowered species grown so many Caucaea plants, among my fa­ from southern Ecuador. Stacy notes seeing vorites in Oncidium (because of their purple col­ only one flower on a type sheet in addition to or), I have seen almost all of Christenson's cri­ John Day's painting. He failed to note that this teria vary from flower to flower and plant to is the only Caucaea having almost all yellow plant, even within the same population. For in­ flowers with a touch of lavender. He did note, stance, I have grown a C. olivaceum with flow­ however, that the callus is similar to that of ers that had a "double" callus. Despite this ab­ C. sanguinolenta. This may be a color variety erration, this flower was identical to others col­ and not a separate species. According to Dod­ lected from the same population at the same son, Caucaea sanguinolenta, although known time in all other aspects. I don't think such an from Colombia, is also found near Cuenca, aberration makes a new species any more than Ecuador. a person born with six fingers is no longer Homo sapiens. Stacy described separate species partly based I am, to say the least, confused by the existing on the type of inflorescence . . . a plant with a taxonomy on Caucaea and think DNA sequenc­ straight raceme became one species, a zigzag ra­ ing will provide answers to some (even most) of ceme another, and branched still another. I find the current questions. With the addition of field this rather difficult to believe, because, in my observation, we may learn more about this beau­ greenhouse, I have had a large plant of Caucaea tiful group of orchids rather than having to rely olivaceum with all three of these forms of inflo­ on the guesswork and intuition of armchair tax­ rescence. This is what triggered my questioning onomists. the number of different species that have been described in the past. Also, within a single pop­ CULTIVATING/RESCUING CAUCAEA ulation of C. olivaceum found near Machachi, Ecuador, all three forms of inflorescence occur. A move from New York City to Cumbaya, a We know that in cultivation, and in the field, suburb of Quito, Ecuador, located at 2300 m, a flower can vary in size, even on the same in- provided advantages for the growing of or- 92 SELBYANA Volume 27(1) 2006 chids-no more heating and no more air con­ trees that housed orchids become depleted and ditioning (Sorry, Con Ed). The night tempera­ even disappear over a period of a few years (or tures here in Cumbaya, where we grow many less), because of slash-and-burn agriculture. Caucaea plants, average 50oP; and the day tem­ When we see this happening, we rescue as many peratures usually peak in the low 80s, sometimes plants as we can carry. This has happened with higher; and, of course, lower when the day is one large population of Caucaea olivaceum that gray. This area of Ecuador really has only two we are now CUltivating. When trees are cut to seasons-wet and dry. The Quito area is rather make space for a potato field or to feed a few dry, so I water almost every sunny day. Other­ cows on secondary growth for a limited period wise, an automated fogging system compensates of time, thousands of orchids (even millions) can for dryness by emitting clouds of humidity ev­ be destroyed. I believe it is time to get govern­ ery few minutes during the day. Humidity, of ment involved in convincing poor farmers that course, rises naturally at night. The greenhouse, they may be able to earn more money by means designed for high-elevation plants, remains open of eco-tourism by leaving orchid-laden trees with "walls" of nylon netting stretched on rather than by chopping them down to clear frames around the perimeter to keep out insects short-lived cropland. and provide natural temperature and air circu­ lation. ACKNOWLEDGMENTS The roofing material is a special double-wall plastic called Sun Stop, claimed by the manu­ I thank Eduardo Sanchez and Alexander Hirtz facturer to block ca. 40% of the heat and light for their assistance and Calaway Dodson, Ed­ of the sun (which is extremely strong here on uardo Sanchez, Hirtz, Stig Dalstrom, and Mark the Equator). Additional shading is provided for W Chase for their insights, comments, and ed­ Caucaea olivaceum plants, because in their nat­ iting. ural habitat, they were shaded by the leaves of their host trees. We grow them in pots or baskets LITERATURE CITED or on cork slabs or logs with sphagnum around the roots. Many varieties of Caucaea nubigena Christenson, E.A. 2000. Hooded . Orchids and C. phalaenopsis also are in cultivation. I try (Arner. Orchid Soc.) 69(10): 952-960. to replicate natural conditions for them, based Stacy, J.E. 1975. Studies of the genus Oncidium. Har­ on my field observations. My wife Rosemarie vard Bot. Mus. Leafl. 24(7): 133-191. and I must be doing something right, because Williams, N.H., M.W. Chase, and W.M. Whitten. 2001. the plants are growing well, and some remain in Phylogenetic positions of , Caucaea, flower for months at a time. a new genus, , and Oncidium phy­ Some people have questioned us about col­ matochilum (: ) based on nuclear and plastid DNA data. Lindleyana 16: lecting plants from the field. Formerly, we took 272-285. only one or two specimens, leaving the popu­ Zelenko, R., B.D. Zelenko, and M.W. Chase. 1997. lation to continue in nature; however, we have The Pictorial Encyclopedia of Oncidium, ZAl seen more than one forest here in Ecuador with Publications, New York City.