166. Carex laxa Wahlenberg, Kongl. Vetensk. Acad. Nya Handl. 24: 156. 1803.
稀花薹草 xi hua tai cao
Rhizome slender stoloniferous. Culms 25-35 cm tall, slender, sometimes slightly pendent at apex, obtusely trigonous, smooth, brownish and bladeless sheathed at base. Leaves shorter than culm, blades 1-2 mm wide, flat, sometimes longitudinally grooved, slightly soft, scabrid on margins, sheathed. Involucral bracts leaflike, with long sheath and short blade. Spikes usually 3, rather remote; terminal spike male, linear-lanceolate; lateral spikes female, oblong, 1-2 cm, subdensely few flowered, peduncles slender, pendent. Female glumes yellowish brown, ovate or oblong-ovate, ca. 3 mm, membranous, green 1-veined, apex obtuse, mucronate. Utricles greenish, suberect, slightly longer than glume, oblong-elliptic, indistinctly trigonous, ca. 3.5 mm, leathery, glabrous, densely papillose, few veined, base gradually narrowed and cuneate, shortly stipitate, apex abruptly contracted into a short beak, beak ferruginous-brown, truncate at orifice. Nutlets rather tightly enveloped in utricle, obovate, trigonous; style exserted from utricle, base not thickened; stigmas 3. Fl. and fr. Jun-Aug.
Swamps, wet places on lakesides or riversides. Heilongjiang, Liaoning, Nei Mongol [Japan, Russia; Europe].