Dulichium arundinaceum

Threeway sedge
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Cyperaceae
Genus: Dulichium
Pers.
Species:
D. arundinaceum
Binomial name
Dulichium arundinaceum
Synonyms[1]
  • Pleuranthus Pers.
  • Cyperus arundinaceus L.
  • Cyperus ferrugineus L.
  • Schoenus spathaceus L.
  • Cyperus spathaceus (L.) L.
  • Scirpus spathaceus (L.) Michx.
  • Dulichium canadense Rich. in C.H.Persoon
  • Dulichium spathaceum (L.) Rich. in C.H.Persoon
  • Schoenus angustifolius Vahl
  • Sparganium trifidum Poir. in J.B.A.M.de Lamarck
  • Scirpus tegetalis Burch.

Dulichium is a monotypic genus of sedge containing the single species Dulichium arundinaceum, which is known by the common name threeway sedge. This is an aquatic or semi-aquatic plant of the lakes, streams, and ponds of the United States and Canada. It has a wide distribution across the two countries, though noticeably absent from the Dakotas and from the Southwestern Deserts.[1][2][3][4][5]

Dulichium arundinaceum has a thick rhizome system and grows to heights approaching a meter. It is reminiscent of bamboo in appearance when new, growing bright green erect stalks in large, grassy stands. Stems are round to slightly triangular in cross-section (though not nearly as angularly triangular as in Cyperus or Carex), and hollow. The leaves are in three ranks along the stem when seen from above (thus the common name "threeway sedge"), with sheaths along the stems, and the inflorescence grows from the leaf axilla. The spikelets are generally lance-shaped and one to three centimeters long when ripe.[2][6]

Two varieties are recognized:[1]

  • Dulichium arundinaceum var. arundinaceum - most of species range including Québec
  • Dulichium arundinaceum var. boreale Lepage - Québec
  1. ^ a b c "Dulichium". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. ^ a b Mastrogiuseppe, Joy (2002). "Dulichium". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 23. New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  3. ^ "Dulichium arundinaceum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
  4. ^ Govaerts, R. & Simpson, D.A. (2007). World Checklist of Cyperaceae. Sedges: 1-765. The Board of Trustees of the Royal Botanic Gardens, Kew.
  5. ^ Rothrock, P.E. (2009). Sedges of Indiana and adjacent states: the non-Carex species: 1-271. Indiana Academy of Sciences.
  6. ^ Department of Ecology, State of Washington, shoreline plants, Dulichium arundinaceum (L.) Britton, dulichium, three-way sedge with detailed description