2. Saccharum formosanum (Stapf) Ohwi, Acta Phytotax. Geobot. 11: 152. 1942.
台蔗茅 tai zhe mao
Erianthus formosanus Stapf, Bull. Misc. Inform. Kew 1898: 228. 1898; E. pollinioides Rendle; Saccharum formosa-num var. pollinioides (Rendle) Ohwi.
Perennial, rhizomatous. Culms 0.7–1.9 m tall, 2–5 mm in diam., nodes glabrous, hirsute below panicle. Leaf sheaths longer or upper shorter than internodes; leaf blades flat or involute, 30–100 × 0.3–0.6 cm, pilose at base, otherwise glabrous, margins scabrid, base straight, apex long acuminate; ligule ca. 0.5 mm, margin ciliolate. Panicle obovate in outline, 15–24 cm, grayish white or pinkish, unbranched, axis 8–12 cm, shorter than racemes or subequaling lowest racemes, silky pilose; racemes 15–30, 11–12 cm, ascending or spreading; rachis internodes ca. 2.5 mm, silky villous, hairs 2–3 times spikelet length. Spikelets 3–3.6 mm; callus hairs short, ca. 0.5 mm; lower glume lanceolate, papery, brown, membranous and pallid near apex, back pilose with white or purplish hairs 2–3 times spikelet length, keels scabrid above, apex attenuate, minutely notched; lower lemma equaling glumes; upper lemma lanceolate, upper margins ciliate, apex subentire, awned; awn slender, 6–8 mm. Anthers 2, 1.5–2 mm. Fl. and fr. Aug–Nov.
* Open grassy hillsides. Fujian, Guangdong, Guizhou, Hainan, Jiangxi, Taiwan, Yunnan, Zhejiang.
Saccharum formosanum is closely related to Eulalia fastigiata (Nees ex Steudel) Stapf ex Bor (S. fastigiatum Nees ex Steudel; Erian-thus fastigiatus (Nees ex Steudel) Andersson) from Bhutan, NE India, and Nepal. The latter species differs in its slightly larger (3.5–4.7 mm) spikelets, shorter spikelet and internode hairs not much exceeding the spikelet, and possession of 3 anthers. The two species are undoubtedly congeneric, but lie on the boundary between Saccharum and Eulalia, and have been placed in different genera in recent Floras. The inflorescence axis is shorter than is usual in Saccharum, but longer than in Eulalia, in which genus the racemes are usually digitate. On balance, the two species seem best placed in Saccharum.