Catasetum

Cymbidieae subtribe Catasetinae

Caespitose monoecious epiphytes, lithophytes or terrestrials. Pseudobulbs spindle-shaped, fibrous, rooting at the base. Leaves several, plicate, distichous, deciduous. Inflorescences erect to pendent basal pedunculate racemes, the floral bracts inconspicuous. Flowers unisexual (usually non-functional when hermaphroditic), dimorphic; the pistillate (“female”) flowers similar throughout the genus, not resupinate, green, with a rigid helmet-like lip; staminate (“male”) flowers highly variable, resupinate or not resupinate, the lip helmet-like to flat, variously lobed and ornamented. Sepals and petals free, spreading, the petals often erect and subparallel with the dorsal sepal. Lip unlobed or three-lobed, saccate, globose to flat, sessile. Column erect, without wings or foot, with a pair of antennae-like triggers, the anther with a terminal beak; pollinia 2, on a common linear stipe and a large viscidium with copious glue.

From the Greek kata, meaning down, and the Latin seta, meaning bristle, referring to the pair of trigger antennae in the staminate flowers.

A genus of about 100 species distributed throughout the Neotropics from Mexico to Bolivia. The genera Clowesia and Dressleria were previously included in a more broadly defined Catasetum. Catasetum is divided into two subgenera, subg. Catasetum and subg.

1 Flowers not resupinate, lip uppermost. 2 1' Flowers resupinate, lip lowermost. 9 2(1) Sepals and petals white, without markings. C. rooseveltianum 2' Sepals and petals green, +/- red suffusion and spots. 3 3(2') Sepals and petals strongly reflexed and parallel to the ovary. C. purum 3' Sepals and petals +/- incurved. 4 4(3') Flowers greenish-yellow, without markings. 5 4' Flowers greenish-yellow with variable maroon and red suffusion and spotting. 7 5(4) Lateral margins of lip smooth, without any fimbriations. 6 5' Lateral margins of lip finely fimbriate. C. viridiflavum 6(5) Apex of lip without conspicuous callus. C. integerrimum 6' Apex of lip with a pair of large rounded calli. C. macroglossum 7(4') Lateral margins of lip smooth, without any fimbriations. C. macrocarpum 7' Lateral margins of lip ciliate or fimbriate. 8 8(7') Lip unlobed, with minutely ciliate lateral margins. C. maculatum 8' Lip three-lobed, the lateral lobes fimbriate, the midlobe triangular to three-lobulate. C. sanguineum 9(1') Apex of lip an elongate cylindric projection as long as the saccate base. C. naso 9' Lip otherwise. 10 10(9') Lip broader than long or suborbicular. 11 10' Lip longer than wide. 22 11(10) Leaves pendent, less than 1 in. (2.5 cm) wide. C. longifolium 11' Leaves erect, more than 1 in. (2.5 cm) wide. 12 12(11') Lateral margins of the lip smooth, not ciliate, fimbriate or toothed. 13 12' Lateral margins of lip ciliate, fimbriate, or toothed. 16 13(12) Flowers large, lip to 1.6 in. (4 cm) long. C. pileatum 13' Flowers small, lip less than 1 in. (2.5 cm) long. 14 14(13') Lip three-lobed; flowers nodding. C. cernuum 14' Lip unlobed; flowers not nodding. 15 15(14') Petals linear-lanceolate; lip green. C. cochabambanum 15' Petals elliptic; lip bright yellow. C. lanxiforme 16(12') Lip small, to 0.4 in. (1.1 cm) long. 17 16' Lip larger, more than 0.8 in. (2 cm) long. 18 17(16) Lip three-lobed, without lateral fringe. C. bicolor 17' Lip unlobed, with long lateral fringe. C. discolor 18(16') Sepals and petals blackish-purple. C. tenebrosum 18' Sepals and petals yellow to green, never blackish- purple. 19 19(18') Lip obscurely three-lobed, with conspicuously fringed lateral margins. 20 19' Lip unlobed, inconspicuously and sparsely fringed on the lateral margins. 21 20(19) Lip with a distinct sac; sepals and petals yellowish- green usually suffused and barred with maroon. C. fimbriatum 20' Lip shallowly concave, without a distinct sac; speals and petals green without darker suffusion or markings. C. trulla 21(19') Lip large, to 2 in. (5 cm) long, usually with a large dark red central spot. C. expansum 21' Lip smaller, to 1 in. (2.5 cm) long, without markings on the lip. C. spitzii 22(10') Lip apex with a field of fleshy projections that are not restricted to the margin or with a distinct apical tuft with projections. 23 22' Lip apex without projections or with a single row of projections along the margin. 26 23(22) Lip midlobe with a distinct apical tuft of fleshy projections subsimilar to the basal callus. C. multifissum 23' Lip without a distinct apical tuft or matching basal callus. 24 24(22') Lip with fleshy processes over the entire surface of the lip. C. tuberculatum 24' Lip with fleshy processes along the margins and on the apical third of the lip. 25 25(24') Apex of lip an unorganized field of fleshy processes, without an additional basal callus. C. cristatum 25' Apex of lip with three keels ornamented with small erect teeth in addition to a basal callus. C. schunkei 26(24) Flowers globose, nodding. C. luridum 26' Flowers opening widely, not nodding. 27 27(26') Central callus on lip conspicuous. 28 27' Central callus on lip absent or inconspicuous. 30 28(27) Callus ovate, similar in shape to the lip; lateral margins of the lip smooth. C. tabulare 28' Callus not ovate, differently shaped than the lip; the lateral margins fimbriate. 29 29(28') Callus a high inverted U-shaped structure. C. dupliscutula 29' Callus ring-shaped around the entrance to the short sac. C. saccatum 30(27') Lip small for the genus, less than 0.8 in. (2 cm) long. 31 30' Lip larger, more than 1 in. (2.5 cm) long. 32 31(30) Lip to 0.3 in. (0.8 cm) long; elliptic in outline. C. microglossum 31' Lip to 0.7 cm) long; triangular in outline. C. quadridens 32(30') Lip distinctly three-lobed, the midlobe inflated, convex, bright yellow. C. galeritum 32' Lip unlobed or obscurely three-lobed, the midlobe (when present) never inflated, convex, or bright yellow. 33 33(32') Lip large, to 1.6 in. (4 cm) long, without any basal callus. C. x tapiriceps 33' Lip smaller, to 1.2 in. (3 cm) long, with an erect basal callus tooth. 34 34(33') Margins of lip with a shaggy fringe, surface of lip smooth. C. barbatum 34' Margins of lip smooth or with irregular scattered minute teeth, surface of lip irregularly warty. C. callosum

Bedell, B. J. 1927. The floral mechanism of Catasetum macrocarpum Rich. (C. tridentatum Hook.). J. Bot. London 65:304-314; Bennett, D. E., Jr., E. A. Christenson and B. Collantes M. 1999. An emerald Catasetum. Orchids 68(5):476-479; Bicalho, H. D. and F. de Barros 1988. On the taxonomy of Catasetum subsect. Isoceras. Lindleyana 3(2):87-92; Braga, P. I. S. 1994. Orquídeas da Amazônia Brasiliera, III. Bradea 6(35):293-296; Couret, P. 1977. Study on the morphology and pigmentation of Catasetum pileatum Rchb.f. and its natural hybrids. Amer. Orchid Soc. Bull. 46:200--208; Darwin, C. 1862. On the three remarkable sexual forms of Catasetum tridentatum, an orchid in the possession of the Linnean Society. J. Proc. Linn. Soc. Bot. 6:151-157; Diaz, N. A. 1986. El primer reporte de Catasetum L. C. Rich. (Orchidaceae) para las Antillas: Catasetum cf. integerrimum Hook. Rev. Jardin Bot. Nac. La Habana 6(2):12-19; Dunsterville, G. C. K. 1980. Some Venezuelan Catasetum species. Amer. Orchid Soc. Bull. 49:5-12; Hills, H. G., N. H. Williams and C. H. Dodson 1972. Floral fragrances and isolating mechanisms in the genus Catasetum (Orchidaceae). Biotropica 4:61-76; Janzen, D. H. 1981. Bee arrival at two Costa Rican female Catasetum orchid inflorescences, and a hypothesis on euglossine population structure. Oikos 36: 177-183; Jenny, R. 1991. Catasetum tabulare Lindl. 1844. Die Orchidee 42(2): Orchideenkartei seite 637-638; Jenny, R. 1991. Catasetum sanguineum Lindl. & Paxton 1854. Die Orchidee 42(2): Orchideenkartei Seite 639-640; Lacerda, K. G. de, Jr. 1998. Catasetum galeatum Lacerda sp. nov. Bradea 8(16):85-88; Lacerda, K. G. de, Jr. 1998. Estudos em Catasetinae (Orchidaceae), Complexo cristatum Lindl., 1. Bradea 8(16):88-96; Lacerda, K. G. de, Jr. 2000. Catasetum lanciferum Lindl., eine bekannte Art mit verschollenem Namen. Die Orchidee 51(5):[069]-[073]; Lacerda, K. G. de, Jr. and V. P. Castro N. 1995. Catasetum osculatum Lacerda & P. Castro sp. nov. Bradea 6(44):381-388; Lacerda, K. G. de, Jr. and J. B. Fernandez da Silva 1998. Catasetum maranhense Lacerda & da Silva sp. nov. Bradea 8(13):69-71; Mansfeld, R. 1932. Die Gattung Catasetum L. C. Rich. Repert. Spec. Nov. Regni Veg. 30:257-275; Mansfeld, R. 1933. Die Gattung Catasetum L. C. Rich. Repert. Spec. Nov. Regni Veg. 31:99-125; Miranda, F. E. and K. G. de Lacerda, Jr. 1992. Estudos em Catasetinae (Orchidaceae), 1. Bradea 6(7):45-60; Miranda, F. E. and K. G. de Lacerda, Jr. 1992. Estudos em Catasetinae (Orchidaceae), 2. Bradea 6(14):122-132; Romero, G. A. and G. Carnevali 1989. A new combination for the orchid flora of southern Venezuela: Catasetum ? tapiriceps Reichb. f. (pro sp.). Lindleyana 4:127-134; Romero, G. A.and G. Carnevali 1991. Catasetum natural hybrids from southern Venezuela, 2. Catasetum xdunstervillei G. Romero & Carnevali. Amer. Orchid Soc. Bull. 60:115-120; Romero, G. A. and G. Carnevali 1991. Catasetum natural hybrids from southern Venezuela, 3. Catasetum ? roseo-album (Hook.) Lindley and C. x wendlingeri Foldats. Amer. Orchid Soc. Bull. 60(8):770-774; Romero, G. A. and R. Jenny 1995. Contributions towards a monograph of Catasetum (Catasetinae, Orchidaceae) I: a checklist of species, varieties, and natural hybrids. Harvard Pap. Bot. 4:59-84; Senghas, K. 1990. Einige neue Arten aus der Subtribus Catasetinae I. Catasetum sektion Anisoceras. Die Orchidee 41(6):212-218; Senghas, K. 1991. Einige neue Arten aus der Subtribus Catasetinae II. Catasetum sektion Isoceras (Teil 1). Die Orchidee 42(1):19-24; Senghas, K. 1991. Einige neue Arten aus der Subtribus Catasetinae II. Catasetum sektion Isoceras (Teil 2). Die Orchidee 42(2):60-64; Silva, M. F. F. da and A. T. de Oliveira 1998. Catasetum cucullatum, uma nova espécie de Orchidaceae para o estado do Amazonas, Brasil. Bol. Mus. Para. Emilio Goeldi, sér. Bot. 14(1):63-67; Teuscher, H. 1957. Catasetum platyglossum Schlechter. Amer. Orchid Soc. Bull. 26:630-633; Vásquez Ch., R. and C. H. Dodson 1997. Doe nuevas especies de Catasetum (Orchidaceae) del Parque Nacional Noel Kempff M. (Santa Cruz, Bolivia). Rev. Soc. Boliviana Bot. 1(2):1-8; Zimmerman, J. K. 1990. Role of pseudobulbs in growth and flowering of Catasetum viridiflavum (Orchidaceae). Amer. J. Bot. 77:533-542; Zimmerman, J. K. 1991. Ecological correlates of labile sex expression in the orchid Catasetum viridiflavum. Ecology 72(2):597-608; Zimmerman, J. K. and J. R. Ehleringer 1990. Carbon isotope ratios are correlated with irradiance levels in the Panamanian orchid Catasetum viridiflavum. Oecologia 83:247-249.