Description from Flora of China
Perennials, often rhizomatous. Culms erect, many-noded, simple or branched. Leaf blades linear to lanceolate, flat, sometimes narrowed to a pseudopetiole; ligule membranous, often hairy on margin or back. Inflorescence terminal, an open or contracted panicle with elongate central axis, primary branches subverticillate, typically capillary, smooth, bearing 1 or more racemes; racemes short, rachis fragile or tough, sessile and pedicelled spikelet of a pair similar, both pedicelled when rachis tough, both fertile, rarely spikelets solitary; rachis internodes and pedicels slender or thickened upward, often with cupular apex. Spikelets usually lanceolate, scarcely compressed; callus subglabrous to shortly bearded; glumes equal, firmly papery, lower glume rounded on back, puberulous to villous, closely many-veined, veins prominent, raised into ridges, apex acute to shortly awned; upper glume usually resembling lower glume, sometimes keeled; lower floret often staminate, lemma lanceolate to ovate, palea usually present; upper lemma deeply 2-lobed, awned from sinus; awn geniculate. x = 10.
Species with a tough rachis and pedicellate spikelets are sometimes separated as the genus Eccoilopus. However, the racemes have distinct joints in these species, so the lack of disarticulation at maturity appears to be a secondary development. The spikelets are typical of Spodiopogon.
The following two species names were not validly published because no Latin description was provided and no type was indicated. They do not appear to correspond with any known species of Spodiopogon. It has not been possible to validate the names here, as the specimens on which they were based have not been located.
“Spodiopogon ludingensis” L. Liu, Fl. Reipubl. Popularis Sin. 10(2): 55. 1997, nom. inval.
泸定大油芒 lu ding da you mang
Perennial. Culms erect, ca. 80 cm tall, 3–4 mm in diam., 3–5-noded. Leaf blades lanceolate, 10–20 × 0.5–1.2 cm; puberulous. Panicle purplish black, ca. 10 cm; branches 1–3 cm; racemes 2–3-noded, one spikelet of a pair sessile, the other pedicellate. Spikelets ca. 4 mm; callus glabrous; lower glume 9–11-veined, veins scabrid, puberulous between veins, apex obtuse or truncate; upper lemma 2-lobed to middle; awn 6–7 mm. Anthers ca. 1.5 mm. Fl. and fr. Aug–Oct.
● Dry mountain slopes; 1500–1600 m. W Sichuan.
“Spodiopogon paucistachyus” L. Liu, Fl. Reipubl. Popularis Sin. 10(2): 57. 1997, nom. inval.
寡穗大油芒 gua sui da you mang
Perennial. Culms erect, stiff, ca. 50 cm tall, 2–4 mm in diam., many-noded, farinose below node. Leaf sheaths purplish, longer than internodes; leaf blades lanceolate, 5–10 × 0.4–0.8 cm, puberulous, base contracted into false petiole, lower margin softly tuberculate-hairy, apex acute. Panicle lax, ca. 5 cm; branches 1–2 per node; racemes with 1 or 2 spikelet pairs; rachis internodes glabrous; pedicels pilose. Spikelets 6–6.5 mm; callus hairs ca. 2 mm; lower glume 9-veined, lower back softly pilose with ca. 3 mm hairs; upper lemma 2-lobed to middle; awn ca. 12 mm. Anthers ca. 2.5 mm. Fl. and fr. summer–autumn.
● Mountain slopes; 2600–2700 m. W Sichuan.
Fifteen species: Turkey eastward to India, Thailand, and Japan, one species extending northward to Siberia; nine species (six endemic) in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)