Panicum amarum |
Panicum paludosum |
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bitter beachgrass, bitter panicgrass, bitter panicum |
aquatic panicum, Chesapeake panicgrass |
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Habit | Plants perennial; rhizomatous, rhizomes stout, glabrous and glaucous throughout. | Plants perennial; more or less cespitose, rhizomatous or stoloniferous, free-floating or rooting in shallow water. | ||||
Culms | 20-250 cm tall, 3-10 mm thick, erect or decumbent, simple or branched from the lower nodes; nodes glabrous; internodes glabrous, glaucous. |
30-150 cm tall, 3-7 mm thick, compressed, spongy, glabrous, decumbent and rooting at the lower nodes in shallow water; nodes glabrous; internodes glabrous, smooth. |
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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. |
usually shorter than the internodes, not keeled, glabrous or sparsely hispid distally; ligules 1-4 mm; blades 10-40 cm long, 5-15 mm wide, flat, glabrous, contracted basally, attenuate distally, apices acute. |
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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. |
10-25 cm long, 5-17 cm wide, shortly exserted or included basally; primary branches 4-12 cm, ascending to spreading, secondary and higher order branches confined to the distal 2/3, pedicels 1-4 mm, sharply 3-angled, ascending to appressed. |
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Spikelets | 4-7.7 mm long, 1.5-2 mm wide, narrowly ovoid, glabrous, acuminate; lower florets staminate. |
3-4 mm long, 0.8-2 mm wide, lanceolate. |
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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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Lower | glumes 0.5-0.9 mm, 1/5 – 1/3 as long as the spikelets, rounded, glabrous, truncate, weakly 1-3-veined; upper glumes and lemmas subequal, glabrous, 9-11-veined, veins prominent, apices acute to accuminate; lower paleas about 2/3 as long as the lower lemmas; lower florets sterile; upper florets 2-2.7 mm, narrowly ellipsoid, smooth, shiny, yellowish. |
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2n | = 36, 54. |
= 54. |
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Panicum amarum |
Panicum paludosum |
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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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MD |
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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.) |
Panicum paludosum is an Asian species that grows in shallow water. It has been found in Baltimore, Maryland, but may not be established there. (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. 470. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Repentia | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Dichotomiflora | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Elliott | Roxb. | ||||
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