1. Dactyloctenium aegyptium (Linnaeus) Willdenow, Enum. Pl. 2: 1029. 1809 [“aegyptiacus”].
龙爪茅 long zhao mao
Cynosurus aegyptius Linnaeus, Sp. Pl. 1: 72. 1753; Chlo-ris mucronata Michaux; Eleusine aegyptia (Linnaeus) Desfontaines; E. pectinata Moench, nom. illeg. superfl.
Annual. Culms slender to moderately robust, geniculately ascending to shortly stoloniferous and mat-forming, infrequently erect, 15–60 cm tall. Leaf sheaths with ciliate margin; leaf blades flat, 5–20 × 0.2–0.6 cm, tuberculate-pilose on both surfaces, apex acute or acuminate; ligule membranous, 1–2 mm, margin ciliate. Inflorescence digitate, racemes 2–9, linear to narrowly oblong, often radiating horizontally. Spikelets broadly ovate, 3–4.5 mm, florets 3–4; lower glume narrowly lanceolate, keel thick, hispidulous; upper glume elliptic to narrowly obovate, keel smooth, extended into a stout scabrid awn 1/2–2 times length of glume body; lemmas ovate, 2.6–4 mm, keel gibbous, hispidulous above middle, often extended into a stout cusp; palea equal to lemma, keels winged, wings ciliolate, tip 2-toothed. Grain ca. 1 mm, broadly obtriangular, transversely rugose. Fl. and fr. May–Oct. 2n = 20, 36, 40, 48.
Disturbed weedy places, especially on sandy soils. Fujian, Guangdong, Guizhou, Hainan, Sichuan, Taiwan, Yunnan, Zhejiang [tropical and warm-temperate regions of the Old World; introduced to America and Europe].
Willdenow misspelled the specific epithet as "aegyptiacus," but this is simply an orthographical error, and does not affect the valid publication of the combination.
This is a widely distributed, annual weed.