An erect perennial herb. Stems branched, green or red, basally decumbent and rooting at the nodes, usually with ascending, appressed hairs in the upper parts, or more rarely ± glabrous throughout or thickly covered with long white hairs. Ocreae glabrous to hispid, membranous, brown, terminating in a spreading, green, foliaceous, undulating limb, 1–9 mm. broad, with a ciliate margin. Leaves sessile or subsessile, variable in shape but often narrow-lanceolate, sometimes dotted with glands, 8–11 (–15) × 0.8–1.8 (–3.5) cm., apically acute, narrowed to the base, sometimes crisped on the margins, usually pubescent, sometimes covered with silky hairs on both faces. Inflorescence a dense raceme, 2–6 cm. long, on long, pubescent peduncles arising in pairs from the uppermost ocreae (singly fide Meisn.). Bracts, at least the lower ones, usually pubescent with ciliate margins and a terminal fringe of cilia, but varying from glabrous and terminally non-ciliate to densely hirsute with long, silky hairs. Perianth pink 3.5–4.5 mm. Tepals 5, ovate-oblong, 2.5–3 mm. long. Styles 2, connate for approximately half their length. Nut ± rounded in outline, 2.5 × 2.5 mm., dark red-brown to black, shining, biconvex-lenticular. Fig. 4/7, p. 23.
