Paspalum distichum |
Paspalum lividum |
|
---|---|---|
knot grass, knotroot paspalum, thompsongrass, water finger-grass |
longtom |
|
Habit | Plants perennial; rhizomatous or cespitose. | Plants perennial; decumbent or cespitose. |
Culms | 5-65 cm, erect; nodes glabrous. |
30-97 cm, erect; nodes glabrous. |
Sheaths | glabrous, sparsely long pubescent distally; ligules 1-2 mm; blades to 14 cm long, 1.8-11.5 mm wide, flat or conduplicate, glabrous or pubescent, apices involute. |
glabrous or pubescent; ligules 2.2-4.7 mm; blades to 38 cm long, 2.3-6.2 mm wide, flat, glabrous or pubescent. |
Panicles | terminal, usually composed of a digitate pair of branches, a third branch sometimes present below; branches 1.4-7 cm, diverging, often arcuate; branch axes 1.2-2.2 mm wide, winged, glabrous, margins scabrous, terminating in a spikelet. |
terminal, with 3-11 racemosely arranged branches; branches 1.5-4 cm, divergent, occasionally arcuate, terminating in a spikelet; branch axes 1.5-2 mm wide, broadly winged, glabrous or sparsely pubescent, margins scabrous, usually slightly conduplicate, occasionally purple. |
Spikelets | 2.4-3.2 mm long, 1.1-1.6 mm wide, solitary (rarely paired), appressed to the branch axes, broadly elliptic, stramineous, sometimes partially purple. |
2.2-2.6 mm long, 1.2-1.5 mm wide, paired, imbricate, appressed to divergent from the branch axes, elliptic to obovate, stramineous (rarely purple-spotted), margins scabrous apically. |
Lower glumes | absent or, if present, to 1 mm and triangular; upper glumes sparsely and shortly pubescent on the back, 3-veined; lower lemmas glabrous, 3-veined; upper florets stramineous. |
absent; upper glumes and lower lemmas glabrous, 5-veined, margins entire; lower lemmas lacking ribs over the veins; upper florets white to pale. |
Caryopses | 1.9-2.1 mm, yellow. |
2-2.2 mm, brown. |
2n | = 20, 30, 40, 48, 60, 61. |
= 40, 60. |
Paspalum distichum |
Paspalum lividum |
|
Distribution |
AL; AR; AZ; CA; FL; GA; ID; KS; KY; LA; MD; MO; MS; NC; NJ; NM; NV; OK; OR; PA; SC; TN; TX; UT; VA; WA; HI; PR; Virgin Islands
|
|
Discussion | Paspalum distichum grows on the edges of lakes, ponds, rice fields, and wet roadside ditches. It is native in warm regions throughout the world, being most abundant in humid areas. In the Western Hemisphere, it grows from the United States to Argentina and Chile. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Paspalum lividum grows in fresh and brackish marshes and ditches. It is native from the Gulf coast of the United States southward through Mexico and Central America to Cuba and Argentina. Plants of P. modestum with pale upper florets may be mistaken for P. lividum, but will have ligules that are only 1-2.3 mm long. Zuloaga and Morrone regard Paspalum lividum as a synonym of P. denticulatum Trin. (http://mobot.mobot.org/W3T/SearclVnwgc.html December 9, 2002). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 575. | FNA vol. 25, p. 597. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Paspalum | Poaceae > subfam. Panicoideae > tribe Paniceae > Paspalum |
Sibling taxa | ||
Synonyms | P. paspaloides | |
Name authority | L. | Trin. ex Schltdl. |
Web links |
|