Panicum dichotomiflorum |
Panicum capillarioides |
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fall panicgrass, fall panicum, knee grass, panic d'automne, smooth witchgrass |
long-beak witchgrass, slender panicgrass |
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Habit | Plants annual or short-lived perennials in the Flora region, perennial in the tropics; usually terrestrial, sometimes aquatic but not floating. | Plants perennial; cespitose from a knotty crown, hirsute, hairs papillose-based or glabrous. | ||||||||
Culms | 5-200 cm tall, 0.4-3 mm thick, decumbent to erect, commonly geniculate to ascending, rooting at the lower nodes when in water, simple to divergently branched from the lower and middle nodes, usually succulent, slightly compressed, glabrous; nodes usually swollen, sometimes constricted on robust plants, glabrous; internodes glabrous, shiny, pale green to purplish. |
30-75 cm tall, 1-2 mm thick, terete to slightly compressed, erect or ascending, stiff, often bent at the nodes, simple or sparingly branched; nodes densely pubescent. |
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Sheaths | compressed, inflated, sparsely pubescent near the base, elsewhere mostly glabrous, sparsely pilose, or hispid, hairs sometimes papillose-based, margins or throat ciliate, with papillose-based hairs; ligules 0.5-2 mm; blades 10-65 cm long, 3-25 mm wide, glabrous or sparsely pilose, often scabrous near the margins, midribs stout, whitish. |
shorter than or equaling the internodes, rounded, hirsute, green or tinged with purple, margins ciliate; ligules 0.5-1 mm; blades 12-30 cm long, 2-12 mm wide, stiffly erect or ascending, flat, pubescent, sometimes sparsely so, hairs papillose-based, bases truncate, apices attenuate. |
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Panicles | 4-40 cm, diffuse, lax, with a few spikelets; branches to 15 cm, alternate or opposite, occasionally verticillate, ascending to spreading, stiff, scabrous; pedicels 1-6 mm, sharply 3-angled, scabrous, expanded to cuplike apices, appressed mostly to the abaxial side of the branches. |
terminal, 15-30 cm long, 10-12(26) cm wide, usually shortly exserted, scarcely overtopping the blades; rachises hispid, sometimes glabrous basally; primary branches alternate or opposite, divergent, secondary branches divergent, most abundant on the distal 1/3 of the primary branches, with 1-3 spikelets; pedicels 2-20 mm, confined to the distal 1/3 of the branches; pulvini poorly developed, shortly pilose. |
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Spikelets | 1.8-3.8 mm long, 0.7-1.2 mm wide, ellipsoid to narrowly ovoid, light green to red-purple, glabrous, acute to acuminate. |
5-6.5 mm long, 1-1.2 mm wide, glabrous, long-acuminate. |
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Lower glumes | 0.6-1.2 mm, 1/4 - 1/3 as long as the spikelets, 0-3-veined, obtuse to acute; upper glumes and lower lemmas similar, exceeding the upper florets by 0.3-0.6 mm, 7-9-veined; lower paleas vestigial to almost as long as the lower lemmas; lower florets sterile; upper florets 1.4-2.5 mm long, 0.7-1.1 mm wide, narrowly ellipsoid, smooth, shiny, stramineous to nigrescent, with pale veins. |
2-3 mm, about 1/2 as long as the spikelets, attached about 0.4 mm below the upper glumes, 5-7-veined, acute to obtuse; upper glumes and lower lemmas 5-6 mm, exceeding the upper florets by 3-4 mm, 9-13-veined; lower florets sterile; lower paleas 1.5-2 mm, acute; upper florets 1.6-2 mm long, 1-1.1 mm wide, smooth, chestnut brown when mature. |
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2n | = 36, 54. |
= 36. |
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Panicum dichotomiflorum |
Panicum capillarioides |
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Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; HI; PR; BC; NB; NS; ON; QC
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TX |
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Discussion | Panicum dichotomiflorum grows in open, often wet, disturbed areas such as cultivated and fallow fields, roadsides, ditches, open stream banks, receding shores, clearings in flood plain woods, and sometimes in shallow water. It is probably native throughout the eastern United States and adjacent Canada, but introduced elsewhere, including in the western United States. Its size and habit may be partly under genetic control, but these features also seem to be strongly affected by moisture levels, soil richness, competition, and the time of germination. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Panicum capillarioides grows in sandy grasslands, oak savannahs, and rangelands from southern Texas to northern 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. 469. | FNA vol. 25, p. 464. | ||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Dichotomiflora | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Name authority | Michx. | Vasey | ||||||||
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