洱源荩草 er yuan jin cao

Lucaea typica Buse in Miquel, Pl. Jungh. 467. 1854; Ar-thraxon breviaristatus Hackel; A. hispidus (Thunberg) Makino var. robustior Welzen; A. junghuhnii (Steudel) Hochstetter; A. maopingensis S. L. Chen & Y. X. Jin; Lucaea junghuhnii Steudel.

Perennial. Culms decumbent, rooting from lower nodes, 60 cm or more long. Leaf sheaths glabrous or tuberculate-hispid; leaf blades ovate or lanceolate, 6–10 cm × 10–23 mm, both surfaces subglabrous to hispid, base amplexicaul, margins pectinate-setose at least toward base, apex cuspidate; ligule 0.5–1 mm. Racemes 5–13, 3–8 cm, pale green or purplish, raceme bases flattened on inner face, flattened surface pubescent; rachis internodes 1/2–4/5 length of sessile spikelets, glabrous or thinly ciliate, hairs 0.2–0.5 mm. Sessile spikelet 4–5.5 mm; lower glume lanceolate, leathery, weakly convex, margins not inflexed, back asperulous, 7–9-veined, small spinulose tubercles along veins, rarely tubercles sparse; upper glume equaling or slightly longer than lower glume, narrowly leathery, hyaline margins 0.6–0.7 mm, midline smooth; lemma margins not ciliate; upper lemma subentire or 2-toothed, teeth 0.1–0.35 mm; awn 5–11 mm; palea absent. Anthers 3, (1.5–)2–3 mm. Pedicelled spikelet absent; pedicel subulate, glabrous or thinly ciliate, up to 2 mm.

Moist places; 1300–2000 m. Guangdong, Yunnan [NE India, Indonesia, N Myanmar, Nepal, Thailand].

Arthraxon typicus resembles A. castratus, but, besides the key characters, differs by its shorter awns and lack of a palea. It is also similar to A. hispidus, but is a more vigorous perennial and can be clearly distinguished by the presence of 3 longer anthers. Awn length is variable and, when short, the awn may be exserted from the spikelet by less than ca. 2 mm.