Bifrenaria

Maxillarieae subtribe Lycastinae

Caespitose to creeping epiphytes and lithophytes. Pseudobulbs usually four-angled, often glossy, frequently becoming orange-bronze with age. Leaves one, stiff, +/- petiolate. Inflorescences basal erect racemes, the peduncle short to elongate. Flowers cupped or tubular, often fragrant. Sepals and petals free, spreading, subsimilar, subequal, the lateral sepals forming a spur with the foot. Lip unlobed, obscurely three-lobed or three-lobed, often pubescent-villose, with a central callus. Column straight, with a short to elongate foot, without wings; pollinia 4, compressed, in two unequal pairs, each pair attached by a separate stipe to a common viscidium.

From the Latin bi, meaning two, and frenum, meaning strap, in allusion to the two caudicles connecting the pollinia to the visicidum.

A genus of 22 species in South America. Two species have been segregated as Cydoniorchis on the basis of their pollinia structure. Species bearing long-pedunculate inflorescences are sometimes separated as Adipe or Stenocoryne.

1 Plants trailing with elongate rhizome segments. B. longicornis 1' Plants caespitose. 2 2(1) Spur apex curved backwards, hook-like. B. calcarata 2' Spur apex straight, not curved or hook-like. 3 3(2') Petals to 0.9 in. (2.2 cm) long, to 0.3 in. (0.8 cm) wide. 4 3' Petals more than 0.9 in. (2.2 cm) long, more than 0.4 in. (1 cm) wide. 6 4(3) Inflorescences slightly longer than the pseudobulbs. B. atropurpurea 4' Inflorescences subequal to the leaves. 5 5(4') Sepals and petals narrowly lanceolate, bright orange with yellow apices. B. aureo-fulva 5' Sepals and petals oblong-elliptic, dark golden yellow. B. vitellina 6(3') Sepals purple throughout. 7 6' Sepals green suffused with yellow-green to pale purple, white or yellow. 8 7(6) Petals purple; flowers smaller, the dorsal sepal to 0.2 in. (0.5 cm) wide, the lip to 0.3 in. (0.8 cm) long. B. magnicalcarata 7' Petals white usually suffused and marked with purple; flowers larger, the dorsal sepal to 0.6 in. (1.5 cm) wide, the lip to 1.6 in. (4 cm) long. B. tyrianthina 8(6') Sepals and petals white. B. harrisoniae 8' Sepals and petals yellow to green, +/- yellow-green or pale purple suffusion. 9 9(8') Inflorescences subsessile, to 0.8 in. (2 cm) long; sepals and petals clear pale yellow. B. aurea 9' Inflorescences pedunculate, to 5.9 in. (15 cm) long; sepals and petals green +/- suffused with yellow-green or pale purple. B. inodora

Hoehne, F. C. 1944. Revisão taxonomica e sistematica do genero Bifrenaria Lindl. Arq. Bot. Edo. São Paulo, n. s., 2:11-14 (reprinted in Orquídea 7:132-136); Senghas, K. 1994. Adipe villosula (Brade) Wolff 1990. Die Orchidee 45(3): Orchideenkartei Seite 759-760; Wolff, M. 1990. Adipe Raf., ein “vergessener Name.” Die Orchidee 41(2):35-37.