Panicum amarum |
Panicum subg. Panicum |
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bitter beachgrass, bitter panicgrass, bitter panicum |
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Habit | Plants perennial; rhizomatous, rhizomes stout, glabrous and glaucous throughout. | Plants annual or perennial; usually cespitose. | ||||
Culms | 20-250 cm tall, 3-10 mm thick, erect or decumbent, simple or branched from the lower nodes; nodes glabrous; internodes glabrous, glaucous. |
usually erect, not compressed. |
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Sheaths | shorter or longer than the internodes, not keeled, glabrous; collars often glaucous and purplish; ligules 1-5 mm; blades 7-50 cm long, 2-13 mm wide, erect or ascending, firm, thick, flat basally, more or less involute towards the apices. |
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. |
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Panicles | 10-80 cm long, 2-17 cm wide, contracted, slightly nodding; primary branches whorled or opposite, strongly ascending to appressed; pedicels 0.5-15 mm, appressed to slightly divergent. |
usually pyramidal, lax and diffuse, varying to contracted and condensed; secondary branches usually present; pedicels divergent to more or less appressed. |
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Spikelets | 4-7.7 mm long, 1.5-2 mm wide, narrowly ovoid, glabrous, acuminate; lower florets staminate. |
ellipsoid to lanceolate, glabrous. |
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Glumes | and lower lemmas relatively thick; lower glumes 2.8-4 mm, 1/2 - 4/5 as long as the spikelets, 3-9-veined, apices of the midveins sometimes scabridulous; upper glumes and lower lemmas extending 1.5-3 mm beyond the upper florets, apices stiffly gaping; upper glumes 3.9-7.6 mm, 5-9-veined; lower lemmas slightly shorter than the upper glumes, 7-9-veined, lower paleas 3-7 mm, oblong-hastate, folded over the anthers; lower florets staminate; upper florets 2.4-3.9 mm long, 1-1.8 mm wide, narrowly ovoid to oblong, glabrous, smooth, shiny, lemma margins clasping the paleas only at the base. |
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Photosynthesis | C4 NAD-me type. |
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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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2n | = 36, 54. |
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Panicum amarum |
Panicum subg. Panicum |
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Distribution |
AL; CT; DE; FL; GA; LA; MA; MD; MS; NC; NJ; NM; NY; PA; RI; SC; TX; VA; WV
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Discussion | Panicum amarum grows in the coastal dunes, wet sandy soils, and the margins of swamps, along the Atlantic Ocean and the Gulf of Mexico from Connecticut to northeastern Mexico. It is also known, as an introduction, from a few inland locations in New Mexico, North Carolina, and West Virginia, as well as in the Bahamas and Cuba. (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.) |
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Key |
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Source | FNA vol. 25, p. 472. | FNA vol. 25, p. 456. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Repentia | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Elliott | unknown | ||||
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