11. Isachne nipponensis Ohwi, Acta Phytotax. Geobot. 4: 30. 1935.
日本柳叶箬 ri ben liu ye ruo
Low herb forming loose mats. Culms slender, creeping, rooting and branching at nodes, flowering branches up to 15 cm tall. Leaf sheaths thinly pubescent, outer margin ciliate; leaf blades lanceolate-ovate, thin, 2–3.5 × 0.5–0.9 cm, abaxial surface glabrous or pilose, adaxial surface hispid with long scattered hairs, margins white, finely scabrid, base obtuse, apex shortly acuminate; ligule ca. 1 mm. Panicle broadly ovate in outline, 2–8 cm, eglandular, rather sparsely branched, spikelets 10–50; branches and pedicels widely spreading, very slender, scaberulous. Spikelets broadly elliptic, (1.3–)1.5–1.8 mm, green infrequently tinged purplish; florets similar; glumes equal to spikelet or lower slightly shorter, ovate-elliptic, shortly hispid above the middle, often with a few stout, sometimes overtopping bristles, apex obtuse, lower glume 3–5-veined, upper glume 5–7-veined; lemmas broadly elliptic, leathery, thinly pubescent near margins and apex. Fl. and fr. summer to autumn. 2n = 40.
Wet shady places; below 1000 m. Fujian, Guangdong, Guangxi, Guizhou, Hunan, Jiangxi, Sichuan, Taiwan, Zhejiang [Japan, Korea (Cheju Island)].
Isachne nipponensis is very close to I. myosotis, but has a rather looser growth, larger leaves and spikelets, and a broader, very open panicle with slender, scaberulous branches.
Isachne nipponensis var. kiangsiensis P. C. Keng (Acta Phytotax. Sin. 10: 21. 1965), described from Jiangxi, has smooth, glandular panicle branches and pedicels and may represent a different species.