Panicum capillare |
Panicum capillare subsp. capillare |
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common panicgrass, common witchgrass, old witch grass, panic capillaire, witch grass, witch panicgrass |
or common panicgrass, witchgrass |
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Habit | Plants annual; hirsute or hispid, hairs papillose-based, often bluish or purplish. | |||||
Culms | 15-130 cm, slender to stout, not woody, erect to decumbent, straight to zigzag, simple to profusely branched; nodes sparsely to densely pilose. |
medium to robust, ascending to erect, rarely delicate or spreading, usually green or red-purple, rarely bluish-green, often branching at the base. |
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Sheaths | rounded, hirsute or hispid, hairs papillose-based; ligules membranous, ciliate, cilia 0.5-1.5 mm; blades 5-40 cm long, 3-18 mm wide, linear, spreading. |
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Spikelets | 1.9-4 mm, ellipsoid to lanceoloid, often red-purple, glabrous. |
1.9-4 mm. |
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Lower | florets sterile; lower glumes 1/3– 1/2 as long as the spikelets, 1-3-veined; upper glumes 1.8-3.1 mm, 7-9-veined, midveins scabridulous; lower lemmas 1.9-3 mm, extending 0.4-1.1 mm beyond the upper florets, often stiff, straight, prominently veined distally; upper florets stramineous or nigrescent, sometimes with a prominent lunate scar at the base, often disarticulating before the glumes, leaving the empty glumes and lower lemmas temporarily persisting on the panicles. |
paleas absent; mature upper florets about 1/2 as wide as long, stramineous or tan, sometimes blackish, without a lunate scar at the base. |
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Panicle(s) | 13-50 cm long, 7-24 cm wide, usually more than 1/2 as long as the plants, included at the base or exserted at maturity, disarticulating at the base of the peduncles at maturity and becoming a tumbleweed; branches spreading; pedicels 0.5-2.8 mm, scabrous, pilose. |
branches spreading; secondary branches and pedicels strongly divergent. |
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2n | = 18. |
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Panicum capillare |
Panicum capillare subsp. capillare |
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Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; PE; QC; SK; Virgin Islands
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Discussion | Panicum capillare grows in open areas, particularly in disturbed sites such as fields, pastures, roadsides, waste places, ditches, sand, and rock crevices, etc. It grows throughout temperate North America, including northern Mexico. It also grows in Bermuda, the Virgin Islands, and sporadically in South America, and has become naturalized in much of Europe and Asia. It appears to hybridize with P. philadelphicum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Panicum capillare subsp. capillare is the common subspecies, growing in weedy and dry habitats throughout the range of the species. Plants in the western United States and Canada have spikelets over 2.6 mm long more often than those in the east. Robust plants germinating early in the season and growing on better soils tend to spread more, and have wider, shorter blades and more exserted panicles than plants in the eastern United States and Canada growing under comparable conditions. They are sometimes included in P. capillare var. occidentale Rydb., but these traits are not well correlated, and several environmental factors apparently affect their expression. Plants in the eastern part of the range with a well-exserted main panicle at anthesis usually arise from seeds germinating relatively late in the season. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25. | FNA vol. 25, p. 457. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum > Panicum capillare | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. capillare var. occidentale, P. capillare var. brevifolium, P. capillare var. barbipulvinatum | |||||
Name authority | L. | unknown | ||||
Web links |
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