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]
| Threeway sedge | |
|---|---|
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Poales |
| Family: | Cyperaceae |
| Genus: | Dulichium Pers. |
| Species: | D. arundinaceum
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| Binomial name | |
| Dulichium arundinaceum | |
| Synonyms[1] | |
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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
Fossil record
editOne fossil fruit of †Dulichium marginatum has been described from a middle Miocene stratum of the Fasterholt area near Silkeborg in Central Jutland, Denmark.[7]
References
edit- ^ a b c "Dulichium". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
- ^ 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.
- ^ "Dulichium arundinaceum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
- ^ Govaerts, R. & Simpson, D.A. (2007). World Checklist of Cyperaceae. Sedges: 1-765. The Board of Trustees of the Royal Botanic Gardens, Kew.
- ^ Rothrock, P.E. (2009). Sedges of Indiana and adjacent states: the non-Carex species: 1-271. Indiana Academy of Sciences.
- ^ Department of Ecology, State of Washington, shoreline plants, Dulichium arundinaceum (L.) Britton, dulichium, three-way sedge with detailed description
- ^ Angiosperm Fruits and Seeds from the Middle Miocene of Jutland (Denmark) by Else Marie Friis, The Royal Danish Academy of Sciences and Letters 24:3, 1985
External links
edit- Jepson Manual Treatment
- Dulichium arundinaceum in the CalPhotos photo database, University of California, Berkeley
- US Geological Survey, Northern Prairie Wildlife Research Center, Three-way Sedge (Dulichium arundinaceum)
- "Dulichium arundinaceum (three-way sedge)". Go Botany. New England Wildflower Society.
- "Dulichium arundinaceum". Native Plant Database. Lady Bird Johnson Wildflower Center, University of Texas at Austin.
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