Epiphytic, caespitose herbs without pseudobulbs. Roots terete, produced from rhizome. Stem abbreviated, enclosed by 3–6 imbricating sheaths, upper ones foliaceous, basal margins sometimes scarious. Leaves conduplicate, articulate, membranaceous, ligulate to oblong or narrowly obovate, acute to abruptly acuminate, abaxially carinate, narrowed at base into conduplicate petiole. Inflorescence lateral, 1–20 per shoot, single-flowered, produced from axils of lower sheaths, peduncle terete, arching or pendent, provided with one or two basal, triangular, membranaceous to scarious bracts; floral bract double, conduplicate, external one widely ovate-infundibuliform, scarious, loose, longer than ovary, the subopposite internal bractlet lanceolate, acuminate. Flowers resupinate, spreading or campanulate, sepals and petals pure white or yellow to cream white or pale green, rarely pale pink to pale purple, often spotted with purple to dark red-brown or tan- brown, heavily marked with orange-red or finely spotted purple toward base, rarely covered with large purple- brown blotches, labellum white or pinkish white to cream or yellow, spotted and flecked with purple to almost solid purple, rarely with a large, central, purple blotch, callus white to yellow, mostly finely spotted with purple, rarely solid purple or pink. Dorsal sepal free, linear-lanceolate to ovate-elliptic, erect to porrect over column, obtuse to acute, sometimes apiculate, mostly concave and dorsally carinate, sometimes reflexed at apex. Lateral sepals lanceolate-elliptic to ovate-oblong or ovate, sometimes subfalcate, mostly acute, spreading to distinctly refl exed, decurrent on column foot, basal margins sometimes involute. Petals spreading or variously porrect, flanking labellum and column, elliptic to lanceolate-elliptic to broadly ovate or oblanceolate, sometimes asymmetrical, broadly obovate-spatulate, acute to abruptly subacuminate, often revolute at apex. Labellum articulate with column foot, entire to trilobed, usually rounded, ovate to obovate, mostly concave at base, blade often folded back at middle, rarely puberulent to pubescent, base cuneaterounded with a claw, apex emarginate to rounded or subacute, basal margins often erect, flanking the column, distal margin mostly crenulate to crisped, rarely long-fimbriate; disc with a basal, mostly bilobed callus, pedicellate and fleshy or sessile and laminar, transversely elliptic or semicircular-incurved. Column straight, semiterete, with a foot, dilated at apex from base into a ventral, fleshy plate, provided with a central keel basally protruding or not into one or more distinct teeth, sometimes with inconspicuous stigmatic wings; anther cap cucullate, subquadrate- rhombic to obtriangular-obovate, flattened, two-celled, pollinia four, in two pairs of different sizes, linear-oblong, subsigmoid to obovoid, on a linear to ovate or obpyriform, hyaline viscidium, basally rounded or attenuate, folded along margins, scarcely distinct from the rectangular stipe; rostellum tridentate; stigma transverse. (FP).
Species of Kefersteinia occur as epiphytes in shady habitats, often growing on the trunks and mossy oldest branches of trees alongside streams. The habitat of Kefersteinia ranges from tropical warm to evergreen and wet forests at elevations of 100–2500 m, although most species are found in premontane forests at mid-elevations (900–1500 m). Some species (namely K. bengasahra D.E.Benn. & Christenson, K. expansa Rchb.f., K. retanae G.Gerlach, K. stevensonii Dressler) are restricted to warm, tropical forests under 500 m, whereas K. guacamayoana Dodson & Hirtz, K. aurorae D.E.Benn. & Christenson, K. pusilla (C.Schweinf.) C.Schweinf., K. pellita, and K. tolimensis Schltr. have been exclusively recorded from forests at elevations of 1700–2500 m. Flowering has been recorded throughout the year, although some species seem to flower consistently during the dry season and others during the rainy months. (FP)
Kefersteinia is a genus of about 60 species collectively ranging from southern Mexico (North America) through Panama (Central America) and Venezuela and Colombia to Suriname and Bolivia in South America. The genus is most diverse along the Andes of Ecuador and Peru (with 19 and 16 species recorded, respectively), and it is particularly well represented in the mountainous areas of Central America up to Costa Rica, where ten species have been recorded so far. Species diversity rapidly diminishes toward the north, with a single species known from Guatemala and southern Mexico. (FP).