In his Flora Franciscana (Greene, 1891) he placed this unique species in a special group of the genus Streptanthus characterized by "Calyx very irregular, the uppermost sepal greatly enlarged, in aestivation conduplicate
over the others".
In the plantlets, cotyledons unfold from a conduplicate
Leaf sheaths generally longer than the internodes, velvety rarely glabrous; blades 26-74 x 0.3-0.6 cm, not basally constricted, linear, usually conduplicate
, pubescent on both surfaces, rarely glabrous, margins scabrous towards the apex, acute apex; ligule 0.5-1 mm long, membranousciliate.
suberosus have a conduplicate
blade that leaves only the abaxial face exposed, which seems to explain the distribution pattern of the glandular trichomes in those organs.
Epiphytic herb, 29 to 32 cm tall not including the inflorescences; pseudobulbs clustered, subcylindrical, compressed, 5.5 to 20.5 mm long, 4.5 to 15 mm wide, green, clothed by 4 triangular to narrowly triangular sheaths, acute to acuminate, scarious-papyraceous, lacking a foliar blade, deciduous; leaf solitary, at the apex of the mature pseudobulb, conduplicate
, oblong to oblong-elliptic, acute, fleshy, 6 to 29 cm long, ca.
Flowers are actinomorphic, with a tubular light violet corolla (4.16 [+ or -]0.02 cm long), three free petals and sepals, petals 2.5 [+ or -]0.1 cm longer than sepals, corolla remains straight during anthesis, with exerted sexual organs, six stamens in two series (4.3 [+ or -]0.38 cm the shortest and 4.8 [+ or -]0.2 cm the largest one), concolorous with the petals, a white, conduplicate
spiral stigma in an elongated, white style 6.04 [+ or -]0.06 cm long.
variegatifolia; the leaves are concolorous, green, ovate to ovate-lanceolate in outline, usually conduplicate
along their midrib with epicuticular wax over a striated or folded epidermis.