Paspalum distichum

L.
Common names: Knotgrass Thompsongrass
Synonyms: Paspalum paspaloides
Treatment appears in FNA Volume 25. Treatment on page 575.

Plants perennial; rhizomatous or cespitose. Culms 5-65 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. 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. 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. 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. Caryopses 1.9-2.1 mm, yellow. 2n = 20, 30, 40, 48, 60, 61.

Distribution

Wash., Pacific Islands (Hawaii), Fla., Puerto Rico, N.J., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., Nev., Va., Virgin Islands, Calif., Ala., Ark., Ga., Ariz., Idaho, Md., Kans., Okla., Utah, Mo., Miss., Ky., Oreg.

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Paspalum distichum"
61 +, 60 +, 48 +, 40 +, 30 +  and 20 +
rounded +
anatomy +  and kranz +
Charles M. Allen +  and David W. Hall +
1 (?) +  and 3 (?) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
0 cm0 mm <br />0 m <br /> (14 cm140 mm <br />0.14 m <br />) +
pubescent +  and glabrous +
usually linear +  and lanceolate occasionally ovate +
0.18 cm1.8 mm <br />0.0018 m <br /> (1.15 cm11.5 mm <br />0.0115 m <br />) +
1.2mm +  and 2.2mm +
spikelike +
1.4 cm14 mm <br />0.014 m <br /> (7 cm70 mm <br />0.07 m <br />) +
not developed +
ringlike +
orbicular +  and elliptical planoconvex or flattened +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
sometimes longer +
Knotgrass +  and Thompsongrass +
branched +  and solid +
5 cm50 mm <br />0.05 m <br /> (65 cm650 mm <br />0.65 m <br />) +
Wash. +, Pacific Islands (Hawaii) +, Fla. +, Puerto Rico +, N.J. +, N.Mex. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Nev. +, Va. +, Virgin Islands +, Calif. +, Ala. +, Ark. +, Ga. +, Ariz. +, Idaho +, Md. +, Kans. +, Okla. +, Utah +, Mo. +, Miss. +, Ky. +  and Oreg. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
uncinate +
bracteate +  and ebracteate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
subterranean +
spreading +  and erect +
dry +  and fleshy +
long-pubescent +  and glabrous +
subsessile +  and shortly pedicellate +
paired +  and not solitary +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
1 +  and 60 +
unisexual +  and bisexual +
compressed +, rounded +  and acuminate +
1.1mm +  and 1.6mm +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Paspalum paspaloides +
Paspalum distichum +
Paspalum +
species +
membranous +
stipitate +  and sessile +
rounded +  and acute +
stramineous +  and dark-brown +
smooth +  and slightly rugose +
smooth +  and slightly rugose +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +