Panicum hallii |
Panicum diffusum |
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Hall panicum, Hall's panic, Hall's panicgrass, Hall's panicum, Hall's witchgrass |
spreading witchgrass, West Indian panicgrass |
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Habit | Plants perennial; cespitose. | Plants perennial; cespitose and shortly rhizomatous. | ||||
Culms | 10-100 cm, 2-10 mm thick, erect, simple or sparingly branched basally; nodes sericeous, pilose or glabrous; internodes usually glaucous. |
(6)25-100 cm, 0.5-3.5 mm thick, spreading to weakly ascending, usually freely branching; nodes pilose, hairs spreading to ascending; internodes pilose, with papillose-based hairs, or sparsely hispid. |
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Sheaths | rounded, glabrous, margins shortly ciliate distally; ligules 0.6-4 mm, of hairs; blades (3)6-15 cm long, 1-5 mm wide, spreading, abaxial surfaces sparsely hirsute, adaxial surfaces more densely so, hairs papillose-based, midribs prominent and not white, margins involute, bases cuneate, apices subulate. |
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Leaves | 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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Spikelets | 2.1-4.2 mm long, 0.8-1 mm wide, usually ovoid, glabrous. |
2.1-2.9 mm long, 0.8-1 mm wide, glabrous. |
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Lower glumes | 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. |
1-1.2 mm, to 1/2 as long as the spikelets, attenuate, 5-9-veined, veins anastomosing apically; upper glumes and lower lemmas similar, extending about 0.5 mm beyond the upper florets, 11-13-veined; lower florets sterile; lower paleas 1-1.3 mm; upper florets 1.5-1.8 mm long, 0.6-0.8 mm wide, smooth. |
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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. |
panicles 3-35 cm long, about 1/2 as wide, shortly exserted; axillary panicles smaller, not fully exserted; rachises scabridulous; primary branches usually solitary, sometimes paired, divergent and widely spaced, secondary branching mostly on the distal 1/3 of the primary branches; pedicels 1-4 mm, spreading to appressed, confined to the distal portions of the secondary branches. |
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2n | = 18. |
= 36. |
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Panicum hallii |
Panicum diffusum |
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Distribution |
AZ; CO; LA; NM; OK; TX; UT
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LA; TX; PR; Virgin Islands |
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Discussion | 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.) |
Panicum diffusum grows along river banks, ditches, and disturbed areas in wet, loamy or clayey soils. Its range extends from Texas to the Caribbean and northern South America. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 466. | 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. lepidulum | |||||
Name authority | Vasey | Sw. | ||||
Web links |