Catasetum and Cycnoches — Part 1 - American Orchid Society

BEGINNER'S SERIES — 25 

Catasetum and Cycnoches — Part 1 

— Catasetums with "Perfect" Flowers 

STEPHEN R. BATCHELOR 

THUS FAR in this series, the emphasis has been on genera which grow almost 

continuously, though slowly. For these genera, beginners are able to adopt 

cultural practices which require little variation. And yet, some genera do not 

grow constantly, but fluctuate between a state of rapid growth and one of nearly 

complete inactivity — all in the course of a year. Treatment of these genera, in 

contrast, must vary considerably for the best growth and flowering. 

Photo: Greg Allikas 

FIGURE 1 — Reaching a leafy maturity, the newest 

pseudobulb of this plant of Catasetum expansum initiates 

four inflorescences in mid-summer. 

Species and hybrids of Catasetum and Cycnoches, two closely related genera, 

are excellent examples of orchids which have a changeable growth rate. Their 

growth generally occurs in a great flush during the spring and summer, only to 

come to a standstill during the fall and winter. This may be disconcerting at first 

to the beginner. But with some experience, it soon becomes apparent that the 

plants follow a cycle of growth, clearly marked by changes in their behavior and 

appearance. Observing these changes, and altering cultural practices 

accordingly, the beginner should have much success with catasetums and 

cycnochcs, for they are among the most vigorous and floriferous of orchids. 

A large part of this series on catasetums and cycnoches will be devoted to

heir cycle of growth, and to how several talented growers meet the fluctuating 

needs of these genera. Prior to that, however, representative species and 

hybrids need to be introduced. Catasetums in particular offer an astounding 

variety of flowers, from the beautiful to the bizarre. Not every one will appeal! 

Just the same, those which lack conventional good-looks often compensate 

with a few surprises. 

PLANT AND FLOWERING HABIT OF CATASETUMS 

The genus Catasetum contains over one hundred epiphytic species native to 

the lower elevations of tropical America. Because of their warm origins, 

catasetums require warm conditions for proper growth and flowering. Though 

flower characteristics and presentation vary widely in this genus, plant habit is 

similar throughout. The plant of Catasetum expansum pictured in FIGURE 1, 

photographed in mid-summer, is representative of the genus. The growth begun 

in the springtime is already reaching maturity, producing a fleshy, cylindrical 

pseudobulb 6 inches (15 cm) high. This pseudobulb is fully ensheathed in a fanlike 

arrangement of eight thin, plicate (pleated) leaves, the largest of which 

measures about 12 inches (30 cm) long and 3 inches (8 cm) wide. The entire 

plant, excluding pot, is over 1'/2 feet (45 cm) high. 

Following closely behind the leafy pseudobulb in FIGURE 1 are those pseudobulbs 

produced in previous years. Their leafless state is an indication of the 

deciduous nature of catasetums. Leaves produced during one growing season 

are usually lost by the beginning of the next. In other words, by the time an eye 

swells at the base of this most recently matured pseudobulb, signaling a 

resumption of active growth, its leaves will have yellowed and fallen, or will be in 

the process of doing so. The actual timing of this leaf-fall, and, consequently, the 

duration of the plant's leafless state, largely depends on the growing conditions 

and the health of the plant. This will be discussed at length in upcoming articles. 

Though a Catasetum pseudobulb will lose its leaves within a year, the bases of 

these leaves remain, forming a dry, papery sheathing. Older pseudobulbs may 

lose this covering, as well as their plumpness, becoming exposed and furrowed 

with age. The thin, upward-growing secondary roots emanating from the potting 

medium in FIGURE 1 are a curious feature of many Catasetum species. 

The plant of Catasetum expansum in FIGURE 1 is also characteristic of the genus 

in that it is producing four inflorescences from the bases of its newest 

pseudobulbs. Though all basal in origin, the inflorescences of catasetums can 

differ in the position they ultimately take. Many, such as those of Catasetum 

expansum pictured in FIGURE 1, are upright, becoming more arching as the 

flowers develop and add weight to the inflorescence. A few are strictly 

pendulous. The initiation of inflorescences from new growth soon after it 

matures results in most catasetums being summer- and fall-flowering. Yet there 

are notable exceptions to this generalization, which should come to light upon 

closer examination of the species and hybrids. 

CATASETUMS WITH PERFECT FLOWERS 

By the title of this first article, I do not mean to suggest that the catasetums 

about to be discussed arc flawless and therefore free from criticism! Rather, this 

title refers to the fact that the flowers of these catasetums have functioning 

male and female parts; they are, in botanical jargon, perfect, or bisexual, 

flowers. This is not a distinguishing feature within the orchid family, yet it is 

within the genus Catasetum. The great majority of Catasetum species have 

unisexual flowers, male flowers and female flowers, a highly unique trait within 

the orchid family. The ten or so Catasetum species with perfect flowers are 

different in this, as well as other floral features. So distinct are they that Dr. 

Calaway H. Dodson, a prominent taxonomist, has proposed separating them into

two genera of their own: Clowesia, to include Catasetum roseum, Ctsm. 

warscewiczii, Ctsm. thylaciochilum, Ctsm. russellianum and Ctstn. glaucoglossa; and 

Dressleria, to contain Catasetum dilectum, Ctsm. eburneum, Ctsm. suavis and one new 

species (Dodson, 1975). 

Beginners will find, however, that for the most part these species with perfect 

flowers are still occasionally called catasetums by orchid growers. Hybrids made 

with these species are registered as Catasetum hybrids. Nevertheless, from a 

horticultural point of view as well, these species need to be treated separately, as 

they offer growers quite a different look from that of most Catasetum species. 

For these reasons, I will maintain here the two separate groups set forth by 

Dodson, while continuing to call these species and their hybrids catasetums. 

CLOWESIA 

The five species classified by Dodson into the genus Clowesia had been set apart 

previously, though not to that degree, as belonging to the Clowesia section of the 

Photo: Greg Allikas 

FIGURE 2 — Catasetum russellianum (syn. Clowesia russelliana) 

genus Catasetum (Hawkes, 1965). Species of the section, or genus Clowesia, differ 

from the majority of catasetums in a number of ways. In plant habit, they are 

considerably smaller. Their pseudobulbs are rarely over 4 inches (10 cm) high, 

often a good deal less, and are more conical than cylindrical in shape. Their 

inflorescences are not upright, or arching, but strongly pendulous, and tend to 

be shorter than most Catasetum species. The flowers of this group, though 

generally smaller, are perhaps the loveliest and most fragrant of all catasetums. 

They are, regrettably, quite typical of the genus in being short-lived, lasting little 

more than a week in most cases. 

Of the group, Catasetum russellianum has the most in common with the genus 

at large. Native to southern Mexico and Central America, this species has 

fragrant, light green flowers striped in a darker green (FIGURE 2). Though the 

sepals are narrower than the petals, both segments are long and well-spaced, 

creating a large and fairly open flower. Measuring 2'/2-3 inches (6.5-8 cm) 

across, these flowers are comparable in size to some of the largest-flowered 

catasetums. Their thin, almost transparent substance, however, sets them apart 

from the waxy flowers characteristic of most Catasetum species. The pouchshaped 

(saccate) lip in the lowermost position of the flower is the most

distinguishing feature of Calasetum russellianum. Catasetum thylaciochilum is very 

similar to Calasetum russellianum in flower form and coloration, but its lip is not 

nearly so pouched (Teuscher, 1977). 

Though the inflorescences of Catasetum russellianum, being pendent, are 

typical of Clowesia, they are exceptional in length and floriferousness, again 

matching the best of the genus. Less robust plants of Catasetum russellianum will 

naturally produce fewer flowers, but 15 to 20 flowers on inflorescences 

approximately 15 inches (38 cm) long can be expected of mature, healthy plants 

(Hawkes, 1965). The flowering season of Catasetum russellianum is like that of 

most catasetums, running from late summer into fall. 

FIGURE 3 — Catasetum warscewiczii 'Severini' HCC/AOS 

Catasetum warscewiczii, native to portions of Central and South America, is 

another species of this group which has fragrant, greenish flowers with darker 

green striping (FIGURE 3), but its similarity with Catasetum russellianum ends 

there. The sepals and petals of Catasetum warscewiczii are equally broad and 

cupped, forming a full, round but small flower 1-1 Vi inches (2.5-4 cm) across. 

The marvelous, trilobed labellum has two distinctly striped side-lobes which 

arc upright, cradling the nose-like column between them. Its wonderfully 

fringed mid-lobe juts out like a bearded chin. The cavity formed at the 

convergence of the three lobes of the lip, with its darker coloration, adds depth 

to the flower. 

Catasetum warscewiczii produces pendent inflorescences, like Calasetum 

russellianum, but they are generally much shorter, less than 6 inches (15 cm) in 

length. Each inflorescence also tends to carry fewer flowers, no more than 10 or 

12, even for those specimen plants which have received cultural awards. Even so, 

the dense and uniform arrangement of flowers on the inflorescence results in a 

concentration of flowers near the plant. This pleasing, cascade effect is enhanced 

when a pseudobulb produces more than one inflorescence, as is often the case with 

Catasetum warscewiczii (FIGURE 3). Unlike Catasetum russellianum and most 

catasetums, Catasetum warscewic-zii tends to bloom during the winter. By this 

time, not only have the newest pseudobulbs matured, they have lost their leaves 

as well. In this way, too, the flowers are shown to their full advantage, without 

obstruction from view by the large leaves typical of this group and the entire 

genus. 

Catasetum roseum has much in common with Catasetum warscewiczii. This Mexican

species also flowers during the winter months from recently matured pseudobulbs 

Grower: Lincoln Adderley Photo: Charles M. Fitch 

FIGURE 4— Catasetum roseum ‘Chico’ CCM/AOS 

which have since lost their leaves. Robust pseudobulbs of Catasetum roseum, like 

Ctsm. warscewiczii, can produce multiple inflorescences, each measuring up to 6 

inches (15 cm) long and carrying a dozen flowers. The flowers of Catasetum 

roseum are also of similar size, usually 1 inch (2.5 cm) across. But unlike Ctsm. 

warscewiczii, Catasetum roseum, as its name suggests, has flowers which are an 

attractive pink overall, with the exception of a green column (FIGURE 4). These 

flowers, in addition, have sepals and petals which are more pointed and less 

cupped. The lip of Catasetum roseum also has a highly fringed mid-lobe, but its 

side-lobes are not as well developed as Ctsm. warscewiczii. 

The specimen plant of Catasetum roseum in FIGURE 4 well illustrates the 

desirable traits of this species. In its leafless state at least, Catasetum roseum 

could certainly be classified as a miniature. The short, densely clustered 

pseudobulbs of this plant are contained in a 6-inch pot. At the same time, the 

plant is flowering profusely on equally compact, 5-inch (13-cm) inflorescences, 

nearly surrounding the plant and its pot in a wreath of 140 flowers. A small 

number of hybrids have been made using species from the Clowesia section of 

Catasetum. Catasetum Rebecca Northen (Grace Dunn [warscewiczii X roseum] X 

roseum), registered by W.W.G. Moir in 1971, is an attractive hybrid involving 

two of the group's most desirable species. The awarded clone of Catasetum 

Rebecca Northen illustrated in FIGURE 5 combines the more rounded, cupped 

shape of Catasetum warscewiczii with the brighter color of Catasetum roseum, 

while maintaining floriferousness and a compact flowering and plant habit. 

When awarded in April, 1978, this clone displayed 47 flowers on three 

inflorescences, all produced by the same plump, leafless pseudobulb. The 

flowers averaged not quite one inch (2.2 cm) across. 

DRESSLERIA 

The four Central and South American Catasetum species with perfect flowers 

which Dodson classified in a new genus called Dressleria provide a vivid contrast 

to the ones just discussed. In plant habit, they tend to be much larger, looking

FIGURE 5-- 

Catasetum Rebecca Northen ‘Marta’ HCC/AOS (Grace Dunn 

[warceswiczii x roseum] x roseum) 

more like typical catasetums. The inflorescences of these species are likewise 

considerably longer, and are upright, or nearly upright, not pendent. Plants of 

Catasetum dilectum (Dressleria dilecta), for example, often have pseudobulbs 8 

inches (20 cm) long, producing inflorescences up to 14 inches (35 cm) in length 

(Bechtel etal., 1981). It is the flowers of Dressleria, however, which are most 

distinct, bearing little resemblance to those of Clowesia. 

The flowers of the four species classified in Dressleria by Dodson are very similar, a 

fact which has caused some confusion in their identification. The flowers 

illustrated in FIGURE 6, for instance, while identified as Catasetum eburneum, bear 

closer resemblance to those of Catasetum dilectum (Dressleria dilecta), as 

described by Dodson (1975) and pictured in Bechtel et al. (1981). In any event, 

these flowers, photographed in summer, are representative of the group. Borne 

approximately a dozen in number on an upright inflorescence bending under 

their weight, these fleshy flowers have conspicuous, helmet-shaped lips. Their 

uppermost position indicates that the flowers are non-resupinate, as opposed to 

the resupinate flowers of Clowesia, with their lips lowermost. The lips of 

Dressleria flowers also lack the highly fringed nature of most Clowesia species, 

and are attached (adnate) to the column, not separate. The columns of the 

flowers pictured in FIGURE 6 are short and wide, and like the lip, have an opening 

or cavity. Strongly reflexed away from the lip, the greenish sepals and petals lack 

the prominence these segments have in Clowesia. Sepals and petals of other 

members of Dressleria, however, are not as reflexed as these. The widest portion 

of the flowers pictured measures less than one inch (2.1 cm) across. species also 

flowers during the winter months from recently matured pseudobulbs.

Grower: Mr. & Mrs. Grenville Seibels, II Photography: Edwin S. Boyett, Jr. 

FIGURE 6-- Catasetum eburneum ‘Memoria Vinton Overholt’, CBM/AOS 

Many of the remaining 90 or so Catasetum species have non-resupinate 

flowers with helmet-shaped lips like thosejust described. Other Catasetum 

species have both resupinate and non-resupinate flowers, depending on whether 

those flowers are male or female! The unisexual catasetums — considered 

catasetums by everyone — will be the subject of the next article for this series 

REFERENCES 

Bechtel, Helmut, Cribb, Phillip and Edmund Launert. 1981. The Manual of Cultivated 

Orchid Species. The MIT Press, Cambridge, Massachusetts. Dodson, C.H. 1975. 

Dressleria and Clowesia: A New Genus and an Old One Revived in the Catasetinae 

(Orchidaceae). Selbyana 1(2): 130. 

Hawkes, Alex D. 1965. Encyclopaedia of Cultivated Orchids. Faber and Faber, 

Limited, London. Teuscher, Henry. 1977. 

Catasetum thylaciochilum — Collector's Item. Amer. OrchidSoc. Bull. 46(11):

Catasetum and Cycnoches — Part 1 - American Orchid Society

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