Panicum bergii |
Panicum urvilleanum |
|
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Berg's panicgrass, Bergs witchgrass |
desert panicgrass, silky panic grass |
|
Habit | Plants perennial; cespitose, with numerous leaves clustered at the base. | Plants perennial. |
Culms | (10)50-140 cm, stout, stiffly erect, branched from the middle and lower nodes; lower nodes sericeous; lower internodes sericeous, hairs papillose-based, upper internodes sometimes glabrous. |
50-100 cm, erect, solitary or in small tufts from stout, scaly, creeping to vertical rhizomes or stolons, simple or branching at the base; nodes densely villous. |
Sheaths | rounded, glabrous or sparsely to densely hispid, hairs not fragile and prickly, not causing skin irritation, margins ciliate; ligules 1-3 mm; blades 3-60 cm long, 2-12 mm wide, flat or involute, ascending, adaxial surfaces densely hirsute basally, less densely so elsewhere, bases attenuate, apices acute. |
densely villous; ligules membranous, ciliate, hairs 1.5-2 mm; blades 20-60 cm long, 4-10 mm wide, ascending to spreading, strigose to subglabrous, flat basally, tapering to a long, involute point. |
Panicles | (4)15-40 cm long, (3)10-25 cm wide, about 1/3 – 1/2 as long as the plants, open, breaking at the base of the peduncles at maturity and dispersed as tumbleweeds, secondary branching mostly confined to the distal 1/3 of the primary branches; rachises densely hispid or glabrous; lower primary branches in whorls of 4-7, stiffly spreading, naked on the lower 1/2; pedicels 3-20 mm, appressed. |
20-30 cm long, 3-9 cm wide, narrow, shortly exserted; branches slender, ascending; secondary branches and pedicels 1-4 mm, crowded, ascending to appressed. |
Spikelets | 2-3 mm long, 0.8-1.2 mm wide, glabrous. |
5-7 mm, densely villous, hairs silvery or tawny-white. |
Lower glumes | 1-1.6 mm, 5-veined, acuminate; upper glumes and lower lemmas similar, 2-2.8 mm, 7-9-veined, exceeding the upper florets by about 0.3 mm; lower florets sterile; lower paleas 1.4-2.2 mm; upper florets 1.5-1.9 mm long, 0.7-1 mm wide, smooth, chestnut brown at maturity. |
about 3/4 the length of the spikelets, 7-11-veined; upper glumes and lower lemmas 7-15-veined; lower florets staminate; lower paleas about as long as the lower lemmas; upper florets striate, margins of the upper lemmas villous, hairs white; lodicules very large. |
2n | = 36. |
= 36. |
Panicum bergii |
Panicum urvilleanum |
|
Distribution |
AL; GA; LA; TX |
AZ; CA
|
Discussion | Panicum bergii is an eastern South American species that now grows in southeastern Texas. It occurs in ditches and shallow, and sporadically flooded depressions in grasslands. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Panicum urvilleanum grows on desert sand dunes and in creosote bush scrubland in the Mojave and Colorado desert regions of southern California, southern Nevada, and western Arizona. It also grows in Peru, Chile, and Argentina. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 464. | FNA vol. 25, p. 475. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Urvilleana |
Sibling taxa | ||
Synonyms | P. pilocomayense | |
Name authority | Arechav. | Kunth |
Web links |