Panicum philadelphicum |
Panicum brachyanthum |
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panic de philadelphie, Philadelphia panic grass, Philadelphia witchgrass |
prairie panicgrass |
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Habit | Plants annual; hirsute, hairs papillose-based, usually yellow-green to green, sometimes purplish. | Plants annual; weak, ascending or spreading. | ||||||||
Culms | 8-100 cm tall, about 1 mm thick, erect to decumbent, simple to profusely branched; nodes sparsely to densely pilose. |
slender, wiry, glabrous, often with minute purple streaks and dots, ascending from a decumbent base, often branching extensively at the base and rooting at the lower nodes. |
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Sheaths | usually shorter than the internodes, glabrous, margins short-ciliate; ligules usually less than 0.3 mm, membranous, erose, ciliate; blades 4-15 cm long (rarely longer), 2-3 mm wide, flat or slightly involute, glabrous on both surfaces, margins scabridulous, especially towards the apices, bases narrowed. |
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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 | 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. |
4-17 cm, 1/2 to nearly as wide as long; branches few, capillary, ascending or spreading, scabridulous, with a few spikelets distally; pedicels 0.5-10 mm. |
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Spikelets | 1.4-2.4 mm long, 0.5-0.7 mm wide, usually green, glabrous. |
3.2-4 mm long, about 1.5 mm wide, broadly ellipsoid or obovoid, tuberculate, hispid, faintly veined, acute or acuminate at the apices. |
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Lower glumes | 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. |
usually less than 1 mm, obtuse or acute; upper glumes and lower lemmas subequal, distinctly tuberculate, hispid, with stiff hairs arising from wartlike bases; upper florets 2.7-3.2 mm long, 1.3-1.6 mm wide, obovoid or ellipsoid, nearly smooth, minutely papillose, or cross-rugulose, subacute to acute. |
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2n | = 18. |
= unknown. |
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Panicum philadelphicum |
Panicum brachyanthum |
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Distribution |
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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AR; LA; MS; OK; TX
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Discussion | 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.) |
Panicum brachyanthum grows in dry, sandy or clayey soils of open areas, remnant prairies, woodland borders, and roadsides and, less commonly, along the margins of bogs and on grassy shores in the western portion of the gulf coast plain. It is restricted to the southern United States. It resembles P. verrucosum in its growth habit, but is more restricted in its distribution. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 459. | FNA vol. 25, p. 487. | ||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Phanopyrum > sect. Verrucosa | ||||||||
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Subordinate taxa | ||||||||||
Synonyms | P. tuckermanii | |||||||||
Name authority | Bernh. ex Trin. | Steud. | ||||||||
Web links |