Schoenoplectus pungens is a species of flowering plant in the sedge family known as common threesquare, common three-square bulrushFlora of North America and sharp club-rush. It is a herbaceous emergent plant that is widespread across much of North and South America as well as Europe, New Zealand and Australia.Kew World Checklist of Selected Plant FamiliesJermy, C., Simpson, D., Foley, M. & Porter, M. (2007). Sedges of the British Isles. B.S.B.I. Handbook No. 1, ed. 3: 1-554. Botanical Society of the British Isles, London.Govaerts, R. & Simpson, D.A. (2007). World Checklist of Cyperaceae. Sedges: 1-765. The Board of Trustees of the Royal Botanic Gardens, Kew.Castroviejo, S. & al. (eds.) (2008). Flora Iberica 18: 1-420. Real Jardín Botánico, CSIC, Madrid.Rothrock, P.E. (2009). Sedges of Indiana and adjacent states: the non-Carex species: 1-271. Indiana Academy of Sciences.Danylyk, I.M. & Honcharenko, V.I. (2009). Schoenoplectus pungens (Vahl) Palla (Cyperaceae), a new species for of the Ukrainian flora. Ukrayins'k Botanichnyi Zhurnal 66: 650-655.Acevedo-Rodríguez, P. & Strong, M.T. (2012). Catalogue of seed plants of the West Indies. Smithsonian Contributions to Botany 98: 1-1192.
Habitat Threesquare is found in open, sun-lit marshes and along the shores of lakes and ponds, in water up to deep. It is resistant to fire.
Description Schoenoplectus pungens is a long-lived perennial herb up to tall. The foliage is dark green, rough and dense. The small flowers are grouped in dense spikelets, with of 1–7 spikelets on each stem. The seeds are brown.
It is closely related to Schoenoplectus americanus, and many Schoenoplectus pungens specimens have long been misidentified as Schoenoplectus americanus.
References
External links Jepson Manual Treatment Washington Burke Museum Photo gallery