3. Echinochloa oryzoides (Arduino) Fritsch, Verh. Zool.-Bot. Ges. Wien. 41: 742. 1891.
水田稗 shui tian bai
Panicum oryzoides Arduino, Animadv. Bot. Spec. Alt. 16, t. 5. 1764; Echinochloa coarctata Kossenko; E. crusgalli (Linnaeus) P. Beauvois subsp. oryzicola (Vasinger) T. Koyama; E. crusgalli var. oryzicola (Vasinger) Ohwi; E. macrocarpa Vasinger; E. oryzicola (Vasinger) Vasinger; E. oryzoides subsp. phyllopogon (Stapf) Tzvelev; E. persistentia Z. S. Diao; E. phyllopogon (Stapf) Stapf ex Kossenko; E. phyllopogon subsp. oryzicola (Vasinger) Kossenko; Panicum oryzicola Vasinger; P. phyllopogon Stapf.
Annual. Culms erect, forming a narrow tuft up to 1 m tall. Leaf sheaths and blades glabrous or rarely lower leaves with a dense tuft of hairs on abaxial side at junction of sheath and blade; leaf blades stiffly erect, linear, flat, 10–30 × 1–1.5 cm, margins thickened and scabrous. Inflorescence 8–15 × 1.5–3 cm; racemes simple. Spikelets light green, ovate, 3.8–6 mm; glumes hispid along veins, lower glume 1/2–2/3 as long as spikelet, acuminate; upper glume acuminate; lower lemma acuminate or with an awn up to 2 cm; upper lemma 3.5–5 mm. Fl. and fr. Jul–Oct. 2n = 54.
A weed of rice fields. Anhui, Guangdong, Guizhou, Hainan, Hebei, Henan, Hunan, Jiangsu, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan [India, Indonesia, Japan, Kazakhstan, Korea, Kyrgyzstan, Pakistan, Russia, Turkmenistan, Uzbekistan; Europe, America].
Echinochloa oryzoides is adapted as a weed of rice (Oryza), which it resembles in habit. A variant from ricefields in Italy has a dense band of hairs on the outer side of the leaf sheath and blade junction, particularly on the lower leaves. This is the basis of the name E. phyl-lopogon.