Panicum hirticaule |
Panicum philadelphicum |
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Mexican panicgrass, roughstalk witchgrass, roughstalk wltchgrass, woodland panic |
panic de philadelphie, Philadelphia panic grass, Philadelphia witchgrass |
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Habit | Plants annual; glabrous or hispid, hairs papillose-based. | Plants annual; hirsute, hairs papillose-based, usually yellow-green to green, sometimes purplish. | ||||||||||||||||
Culms | 11-110 cm, erect to decumbent; nodes shortly hirsute or glabrous. |
8-100 cm tall, about 1 mm thick, erect to decumbent, simple to profusely branched; nodes sparsely to densely pilose. |
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Sheaths | shorter than the internodes, greenish to purplish, glabrous or with papillose-based hairs, ciliate on 1 margin, glabrous on the other; collars hirsute; ligules 1.5-3.5 mm, of hairs; blades 3-30 cm long, 3-30 mm wide, flat, usually hirsute or sparsely pubescent, hairs papillose-based, sometimes glabrous, bases rounded to cordate-clasping, margins ciliate, cilia papillose-based, apices acute. |
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Leaves | often crowded basally; sheaths rounded, usually longer than the internodes, hispid, hairs papillose-based, to 5 mm; ligules 0.5-1.5 mm; blades 3-30 cm long, 2-12 mm wide, linear, ascending to erect, flat, hirsute to sparsely pilose, greenish or purplish, bases truncate to subcordate and ciliate on the margins, apices acute. |
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Panicles | 9-30 cm long, 5-8 cm wide, erect or nodding, partially included to well-exserted, rachises glabrous or sparsely hispid basally; primary branches usually alternate to opposite, divergent, secondary branches and pedicels confined to the distal 2/3; pulvini inconspicuous; secondary branches appressed; pedicels 9-27 mm, appressed. |
7-27 cm long, 4-24 cm wide, 1/4 - 1/3 as long as the plants, diffuse, usually exserted at anthesis, not breaking at the base of the peduncles to become a tumbleweed; rachises glabrous or sparsely pilose basally; primary branches spreading, secondary branches and pedicels confined to the distal 2/3 secondary branches diverging to appressed, with 1-4 spikelets; pedicels 3-15 mm, spreading to appressed, scabrous or hirsute; pulvini glabrous or pilose. |
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Spikelets | 1.9-4 mm long, 0.8-1 mm wide, ovoid to almost spherical, often reddish-brown, glabrous, veins prominent, scabridulous, apices abruptly acuminate. |
1.4-2.4 mm long, 0.5-0.7 mm wide, usually green, glabrous. |
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Lower glumes | 1.3-2.4 mm, 1/2 - 3/4 as long as the spikelets, 3-5-veined; upper glumes 1.8-3.3 mm, 7-11-veined; lower florets sterile; lower lemmas similar to the upper glumes, 9-veined; lower paleas 0.4-0.9 mm; upper florets 1.5-2.4 mm long, 0.4-0.8 mm wide, ellipsoid, smooth or conspicuously papillate, shiny, stramineous, often with a lunate scar at the base. |
0.5-0.9 mm, usually less than 1/2 as long as the spikelets, 3-4-veined, truncate to acuminate; upper glumes 1.6-2 mm, 7-veined, veins not prominent; lower lemmas 1.6-1.9 mm, 7-9-veined, veins not prominent; lower paleas absent; lower florets sterile; upper florets 1.5-1.7 mm long, about 0.4 mm wide, often dark brown, sometimes disarticulating, apices minutely papillose. |
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2n | = 18. |
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Panicum hirticaule |
Panicum philadelphicum |
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Distribution |
AZ; CA; NM; NV; OK; TX; WA
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AL; AR; CT; DC; DE; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NB; NS; ON; QC
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Discussion | Panicum hirticaule grows in rocky or sandy soils in waste places, roadsides, ravines, and wet meadows along streams. Its range extends from southeastern California and southwestern Texas southward through Mexico, Central America, Cuba, and Hispaniola to western South America and Argentina. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Panicum philadelphicum grows in open areas such as fallow fields, roadside ditches, receding shores, and rock crevices. It is restricted to the eastern part of the Flora region. It intergrades with P. capillare, possibly as a result of hybridization, especially in the southeastern United States. Seeds germinating on receding shores in late summer often produce tiny plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 460. | FNA vol. 25, p. 459. | ||||||||||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | ||||||||||||||||
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Subordinate taxa | ||||||||||||||||||
Synonyms | P. pampinosum | P. tuckermanii | ||||||||||||||||
Name authority | J. Presl | Bernh. ex Trin. | ||||||||||||||||
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