Panicum gymnocarpon
Plants perennial; forming extensive colonies by their long, decumbent, sprawling basal branches and stolons. Culms 60-130 cm, thick, glabrous, rooting profusely at the lower nodes; nodes glabrous, often with a dark green band. Sheaths usually shorter than the internodes, glabrous, prominently veined; ligules 0.5-1.5 mm; blades 15-40 cm long, 7-25 mm wide, tapering from midlength, flat, both surfaces glabrous, bases subcordate, margins scabrous to smooth, widest at the base, apices acute. Panicles 10-40 cm long, 7-20 cm wide, open, with straight, rigid rachises; branches whorled, stiffly ascending, with short, appressed, higher order branches; ultimate branchlets 1-sided, with solitary spikelets or small clusters of spikelets; pedicels 0.1-1.5 mm. Spikelets 5.5-7 mm long, about 1 mm wide, narrowly lanceoloid, glabrous. Glumes spreading apart at maturity, keeled, prominently veined, scabrous along the midveins; lower glumes nearly as long as the lower lemmas; upper glumes and lower lemmas 3-veined, spreading, greatly exceeding the upper florets, lower lemmas longer than the upper glumes, arcuate; lower florets sterile; lower paleas thin; upper florets 1.9-2.2 mm, less than 1/3 as long as the spikelets, obovoid, lustrous, pale to brownish, acute, often short-stipitate. 2n = 40.
Discussion
Panicum gymnocarpon grows in swamps, wet woodlands, and the marshy shores of lakes and streams. It is also found occasionally in shallow water, often in the shade. It is restricted to the United States.
Selected References
None.