Panicum flexile |
Panicum subg. Panicum |
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panic flexible, wiry panic grass, wiry witch grass |
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Habit | Plants annual; delicate, green or yellow-green. | Plants annual or perennial; usually cespitose. |
Culms | 10-75 cm, about 1 mm thick, simple or with erect basal branches; nodes densely pilose, hairs ascending; internodes glabrous or shortly pubescent distally. |
usually erect, not compressed. |
Sheaths | longer than the internodes, green to purplish, hispid, margins sparsely ciliate; ligules 0.5-1.5 mm; blades 3-32 cm long, 1-7 mm wide, ascending to erect, linear, narrowing basally, flat or the margins involute, surfaces sparsely hirsute or pilose (rarely glabrous), hairs near the base papillose-based, margins prominent, apices acute. |
not keeled; ligules of hairs, or membranous and, usually, ciliate; blades with vascular bundles separated by 2-6 radially arranged, tabular mesophyll cells and surrounded by a double sheath, cells of the inner sheath thick-walled, cells of the outer sheath with thinner cell walls and usually centripetal chloroplasts; chloroplasts with well-developed grana. |
Panicles | 5-45 cm long, 1-6 cm wide, at least 1/2 as long as the plants and 3 times longer than wide, open; rachises glabrous; primary branches usually alternate or subopposite, ascending to slightly divergent, secondary branches and pedicels attached to the distal 2/3; secondary branches diverging; pedicels 0.5-17 mm, ascending to appressed. |
usually pyramidal, lax and diffuse, varying to contracted and condensed; secondary branches usually present; pedicels divergent to more or less appressed. |
Spikelets | 2.5 - 3.7 mm long, 0.6-1.1 mm wide, narrowly ovoid, glabrous, acute; lower glumes 0.8-1.3 mm, 1/3 – 1/2 as long as the spikelets, acuminate; upper glumes 2.3-3.3 mm, 7-9-veined, exceeding the upper florets by about 0.6 mm; lower florets sterile; lower lemmas 2.2-2.7 mm, exceeding the upper florets by about 0.6 mm, 7- or 9-veined, apices scabridulous, pointed; lower paleas absent; upper florets 1.6-1.7 mm long, about 0.6 mm wide, usually smooth, usually pale, sometimes becoming dark at maturity. |
ellipsoid to lanceolate, glabrous. |
Lower glumes | 1/5 - 4/5 the length of the spikelets, 1-11-veined; upper glumes and lower lemmas (5)7-15-veined; lower florets usually sterile; upper florets smooth, shining; upper paleas with compound or compound and simple papillae towards the apices, x = 9. |
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Photosynthesis | C4 NAD-me type. |
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2n | = 18. |
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Panicum flexile |
Panicum subg. Panicum |
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Distribution |
AL; AR; CT; DC; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; ND; NJ; NY; OH; OK; PA; SC; SD; TN; TX; UT; VA; VT; WI; WV; ON; QC
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Discussion | Panicum flexile grows in fens and other calcareous wetlands, in dry, calcareous or mafic rock barrens, and in open woodlands, especially on limestone derived soils. It is restricted to the Flora region. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
There are approximately 50 species of Panicum subg. Panicum in the Western Hemisphere (Zuloaga 1987), 21 of which grow in the Flora region. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 460. | FNA vol. 25, p. 456. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum |
Sibling taxa | ||
Subordinate taxa | ||
Name authority | (Gatt.) Scribn. | unknown |
Web links |