细秆萤蔺 xi gan ying lin

Scirpus hotarui Ohwi, Repert. Spec. Nov. Regni Veg. 36: 44. 1934; Schoenoplectus juncoides (Roxburgh) Palla subsp. hotarui (Ohwi) Soják; Scirpus juncoides Roxburgh var. hotarui (Ohwi) Ohwi.

Plants annual. Roots fibrous. Culms tufted, 13-40 cm tall, 0.7-1 mm thick, terete, slender, rigid, shiny, clothed at base with ca. 3 bladeless sheaths. Involucral bracts erect. Inflorescence a pseudolateral head with 1-3(or 4) spikelets. Spikelets ovoid, 6-14 × 4-6 mm, apex acute. Glumes ovate-orbicular, 3-4.5 mm, brownish tinged on both sides of green costa, apex rounded. Perianth bristles 6, ca. 1.5 × as long as nutlet. Stigmas 3. Nutlets blackish at maturity, broadly ovate-orbicular, 2-2.5 mm, trigonous, transversely wrinkled.

Wet places; ca. 1200 m. Jilin, S Liaoning [Japan, Korea, N Myanmar, Russia (Far East)].

This species can be easily discerned by the slender, rigid, and spiny culms with only 1-3 spikelets in contrast to the thicker, subrigid, and opaque culms bearing 4-9 spikelets of Schoenoplectus juncoides. Schoenoplectus hotarui, unlike S. juncoides, is found growing more frequently in natural habitats rather than as a rice field weed and has a more northerly distribution.