29. Eleocharis palustris (Linnaeus) Roemer & Schultes, Syst. Veg. 2: 151. 1817.
沼泽荸荠 zhao ze bi qi
Scirpus palustris Linnaeus, Sp. Pl. 1: 47. 1753; Eleocharis eupalustris H. Lindberg; E. intersita G. Zinserling.
Perennials. Rhizomes creeping. Culms a few tufted, 10-100 cm tall, 2-3 mm thick, few ribbed and longitudinally sulcate, obscurely tuberculate. Leaf sheaths 1 or 2, basally blood-red purple, tubular, 3-7 cm, mouth slightly obliquely truncate. Spikelet oblong, narrowly oblong, or ellipsoid, 0.6-2.5 cm × 3-5 mm, many flowered, apex obtuse-rounded. Basal 2 glumes empty; basalmost glume amplexicaul for 1/2 or more of spikelet base; fertile glumes with a narrow green band medially and dark blood-red on sides, ovate to ovate-lanceolate, 3-4 × 1-1.5 mm, membranous, margin broadly hyaline, apex obtuse. Perianth bristles 4-6, shorter to slightly longer than nutlet, slightly curved, spreading outward, densely retrorsely spinulose. Stigmas 2. Nutlet at first yellowish then becoming brownish, obovoid, broadly obovoid, or globose-ovoid, 1.2-1.4 × 0.8-1 mm, unequally biconvex, smooth or rarely slightly prominently reticulate; persistent style base ovoid-oblong to oblong-conic, much longer than wide, 1/2-3/5 as long and ca. 1/2 as wide as nutlet, spongy, apex obtuse to rounded. Fl. and fr. Jun-Jul. 2n = 15, 16.
Shallow water margins in valleys, wet meadows, water of canals; 100-4000 m. Gansu, Hebei, Heilongjiang, Jilin, Nei Mongol, Ningxia, Qinghai, Shaanxi, Xinjiang [Afghanistan, Japan, Kazakhstan, Mongolia, Nepal, Russia; N Africa, SW Asia, Atlantic Ocean islands, Europe, North America].