长芒草沙蚕 chang mang cao sha can

Tripogon japonicus (Honda) Ohwi; T. longearistatus subsp. japonicus (Honda) T. Koyama; T. longearistatus var. japonicus Honda; T. panxianensis H. Peng.

Culms 15–30 cm tall. Basal leaf sheaths papery; leaf blades 4–13 × ca. 0.1 cm, adaxial surface glabrous or loosely pilose, abaxial surface glabrous. Racemes 8–20 cm, usually slightly flexuose, spikelets loosely erect, distant by about their own length along the slender rachis. Spikelets 4.5–9 mm, pale green to dark gray; florets 4–7(–9), loosely arranged, rachilla visible; lower glume linear-lanceolate, asymmetrical, broadened or toothed on one side, 2.5–3 mm, subacute to acuminate; upper glume narrowly lanceolate-oblong, 4–4.5 mm, apex acuminate-rostrate or emarginate and mucronate; lemmas elliptic-lanceolate, 2.5–3.3 mm to sinus, 2-dentate, central awn 3.6–8 mm, stiff, strongly reflexed, teeth acute, lateral veins extended into 0.3–2 mm awns arising free from lemma tooth or from its outer margin; palea keels very narrowly winged, ciliolate. Anther 1, 1–1.5 mm. Fl. and fr. Sep–Oct.

Rocky slopes; 300–1000 m. Fujian, Gansu, Guangdong, Guizhou, Hunan, Jiangxi, Shaanxi, Sichuan, Yunnan, Zhejiang [Japan, Korea].

Tripogon longearistatus is close to T. filiformis, with which it is sometimes confused. They can usually be distinguished on habit. In T. longearistatus, the widely spaced spikelets with stiff, strongly reflexed awns make it one of the easiest Chinese species to recognize. Moreover, there is little overlap in their geographic range: T. filiformis is an upland and high-altitude species, whereas T. longearistatus is confined to the eastern lowlands.

The name "Tripogon coreensis var. longearistatus Hackel ex T. Mori" (Enum. Pl. Corea, 56. 1922) is a nomen nudum and was therefore not validly published; "T. chinensis var. longearistatus Hackel ex Honda" was not validly published because it was merely cited as a synonym in the protologue of T. longearistatus; and the same combination published by I. C. Chung (J. Wash. Acad. Sci. 45: 216. 1955) was not validly published because a full and direct reference to the basionym was not provided.