Sobralia

Epidendreae subtribe Sobraliinae

Medium to large caespitose terrestrials, lithophytes or rarely epiphytes. Stems erect, leafy, usually unbranched. Leaves one to many, elliptic to lanceolate, rarely linear, sessile, acute-acuminate, pleated, often clustered toward the stem apex. Inflorescences terminal racemes, occasionally axillary in the upper leaf axils, sessile or pedunculate, often successively one-flowered. Flowers membranous, usually ephemeral, often gregarious. Sepals and petals free, spreading, the petals ofen wider than the sepals. Lip unlobed to three-lobed, usually tubular at the base, often with undulate margins, the callus absent or present, variable, usually of a pair of short basal keels and low linear parallel longitudinal keels or ridges, the keels often toothed or fimbriate. Column club-shaped, winged with the wings embracing the column apex, without a foot; pollinia 8, soft, sessile on a large common viscidium.

Named to honor Francisco Sobral, an 18th century Spanish physician and botanist.

A genus of about 95 species ranging from Mexico to Bolivia. Species-level taxonomy of Sobralia is rather problematic and research is largely hampered by the usually ephemeral flowers which typically make poor herbarium specimens. A few species with non-tu

1 Inflorescences axillary. 2 1' Inflorescences terminal. 5 2(1) Flowers not resupinate, the lip held uppermost. S. rupicola 2' Flowers resupinate, the lip held lowermost. 3 3(2') Callus keels smooth; lip not tubular at the base. S. altissima 3' Callus keels laciniate-toothed; lip tubular at the base. 4 4(3') Apex of lip with a boss of long trichomes. S. dichotoma 4' Apex of lip without trichomes. S. speciosa 5(1') Petals fimbriate. S. fimbriata 5' Petals not fimbriate. 6 6(5') Lip three-lobed, not tubular, the midlobe oriented downwards and at 360? to the dorsal sepal; flowers brilliant cerise-magenta. 7 6' Lip unlobed or obscurely three-lobed, usually strongly tubular, the midlobe not so oriented; flowers variously colored. 8 7(6) Lip without callus keels, spotted at the base. S. amabilis 7' Lip with a single undulate callus keel, not spotted at the base. S. callosa 8(6') Flower nodding-pendent by a curved ovary. S. infundibuligera 8' Flowers erect or horizontal. 9 9(8') Sepals and petals dark bronze; the leaf sheaths densely covered with dark red trichomes. S. atropubescens 9' Sepals and petals variously colored; the leaf sheaths glabrous or inconspicuously pubescent. 10 10(9') Sepals and petals yellow or orange. 11 10' Sepals and petals white or pink-purple. 14 11(10) Flowers large, the dorsal sepal to 3.9 in. (10 cm) long. S. xantholeuca 11' Flowers smaller, the dorsal sepal less than 2 in. (5 cm) long. 12 12(11') Stems normally with one leaf. S. fragrans 12' Stems with several leaves. 13 13(12') Flowers solitary. S. crocea 13' Flowers typically produced in pairs. S. suaveolens 14(10') Leaves linear, to 0.3 in. (0.8 cm) wide. S. stenophylla 14' Leaves lanceolate to elliptic-ovate, more than 0.8 in. (2 cm) wide. 15 15(14') Inflorescences pedunculate racemes. 16 15' Inflorescences sessile. 21 16(15) Sepals and petals pink to purple. 17 16' Sepals and petals white. 19 17(16) Sepals and petals extremely pale lavender-pink. S. rosea 17' Sepals and petals magenta to dark rose-purple. 18 18(17') Lip purple-striped, without a thickened central ridge. S. paradisiaca 18' Lip not purple-striped, with a yellow central ridge. S. ruckeri 19(16') Leaves lanceolate, to 1.6 in. (4 cm) wide. S. liliastrum 19' Leaves elliptic or elliptic-lanceolate, more than 2 in. (5 cm) wide. 20 20(19') Flowers small, the dorsal sepal to 2.3 in. (6 cm) long. S. gloriosa 20' Flowers large, the dorsal sepal to 4.1 in. (10.5 cm) long. S. pulcherrima 21(15') Blade of the lip without keels or ridges. 22 21' Blade of lip with keels or ridges. 26 22(21) Lip greenish-white. S. macrophylla 22' Lip pink to red. 23 23(22') Lip rose-pink to magenta. 24 23' Lip dark blood red. S. helleri 24(23) Petals acute. S. fenzliana 24' Petals obtuse. 25 25(24') Stems branching with age (Mesoamerica). S. decora 25' Stems unbranched (South America). S. sessilis 26(21') Sepals and petals white to greenish-white. 27 26' Sepals and petals rose-pink to magenta. 30 27(26) Flowers small, the dorsal sepal to 1.2 in. (3 cm) long. S. candida 27' Flowers large, the dorsal sepal more than 2 in. (5 cm) long. 28 28(27') Lip striped and spotted with red-violet. S. lindleyana 28' Lip without red-violet markings. 29 29(28') Blade of lip with five low keels. S. powellii 29' Blade of lip with 11 low keels. S. virginalis 30(26') Lip large, more than 1.5 times long as wide, to 3.9 in. (10 cm) long. S. macrantha 30' Lip smaller, less than 1.5 times long as wide, to 3 in. (7.6 cm) long. 31 31(30') Leaves lanceolate, to 2 in. (5 cm) wide; callus keels smooth (South America). S. violacea 31' Leaves broadly elliptic, to 2.7 in. (7 cm) wide; callus keels warty toward the lip apex (Mesoamerica). S. warscewiczii

Allen, P. H. 1958. Sobralia intermedia. Amer. Orchid Soc. Bull. 27(8):531-535; Bennett, D. E., Jr., and E. A. Christenson 1999. Sobralia altissima. Orchids 68(11):1112-1114; Bennett, D. E., Jr., E. A. Christenson, A. Moises Cavero B. and M. Leon M. 1996. The Sobralias of Tingo Maria, Peru. Orchids 65(8):820-825; Benzing, D. H., D. W. Ott and W. E. Friedman 1982. Roots of Sobralia macrantha (Orchidaceae): structure and function of the velamen-exodermis complex. Amer. J. Bot. 69:608-614; Collantes, B. and M. León 1999. Inquil, Symbol of Carnival in Huachocolpa, Peru. Orchids 68(11):1102-1111; Dunsterville, G. C. K. 1980. Orchids of Venezuela: Sobralia sessilis, an orchid hunt in an orchid herbarium. Amer. Orchid Soc. Bull. 49:486-488; Dunsterville, G. C. K. and E. Dunsterville 1975. Some Venezuelan sobralias. Amer. Orchid Soc. Bull. 44(3):193-199; Dunsterville, G. C. K. and E. Dunsterville 1981. Sobralia ruckeri, a jinx-afflicted beauty queen. Amer. Orchid Soc. Bull. 50(2):176-180; Green, T. 1999. Sobralias. Orchids 68(9):912-921; Pabst, G. F. J. 1979. Additamenta ad Orchideologiam Brasiliensem, XXXI. Bradea 3(2):11-12; Prutsch, J., A. Schardt and R. Schill 2000. Adaptations of an orchid seed to water uptake and -storage. Plant. Syst. Evol. 220:69-75; Teuscher, H. 1965. Collectors Item: Sobralia mucronata and S. lindleyana. Amer. Orchid Soc. Bull. 34(11):994-997.