Panicum philadelphicum |
Panicum hallii |
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panic de philadelphie, Philadelphia panic grass, Philadelphia witchgrass |
Hall panicum, Hall's panic, Hall's panicgrass, Hall's panicum, Hall's witchgrass |
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Habit | Plants annual; hirsute, hairs papillose-based, usually yellow-green to green, sometimes purplish. | Plants perennial; cespitose. | ||||||||||||
Culms | 8-100 cm tall, about 1 mm thick, erect to decumbent, simple to profusely branched; nodes sparsely to densely pilose. |
10-100 cm, 2-10 mm thick, erect, simple or sparingly branched basally; nodes sericeous, pilose or glabrous; internodes usually glaucous. |
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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. |
often crowded basally; sheaths rounded, glabrous or hirsute, hairs fragile, papillose-based, margins sometimes ciliate distally; ligules 0.6-2 mm; blades 4-23 cm long, 1-10 mm wide, erect to spreading, flat or sometimes involute (on sterile branches), often curling at maturity, glaucous, abaxial surfaces sometimes with prominent papillae along the midribs, bases rounded or narrowing to the sheaths, margins cartilaginous, ciliate basally, scabridulous elsewhere, 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. |
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Spikelets | 1.4-2.4 mm long, 0.5-0.7 mm wide, usually green, glabrous. |
2.1-4.2 mm long, 0.8-1 mm wide, usually ovoid, glabrous. |
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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. |
1.2-2.4 mm, 1/2 - 3/4 as long as the spikelets, attenuate; upper glumes and lower lemmas similar, 7-11-veined, acuminate, extending 0.3-1.2 mm beyond the upper florets; lower florets sterile; lower paleas 0.8-2 mm; upper florets 1.5-2.4 mm long, 0.7-1.2 mm wide, ovoid to ellipsoid, smooth, nigrescent. |
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Terminal | panicles 7-31 cm long, 3-15 cm wide; rachises glabrous, tending to break at maturity; branches usually alternate, slender, stiff, ascending to divergent; pedicels 1-15 mm, appressed. |
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2n | = 18. |
= 18. |
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Panicum philadelphicum |
Panicum hallii |
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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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AZ; CO; LA; NM; OK; TX; UT
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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 hallii grows on sandy, gravelly, or rocky land, including roadsides, pastures, rangeland, oak and pine savannahs, chaparral, and moist areas in deserts and on mesas. Its range extends from the southwestern United States to southern Mexico. (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. 466. | ||||||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | P. tuckermanii | P. lepidulum | ||||||||||||
Name authority | Bernh. ex Trin. | Vasey | ||||||||||||
Web links |