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knot grass, knotroot paspalum, thompsongrass, water finger-grass

Vasey grass, Vasey's grass

Habit Plants perennial; rhizomatous or cespitose. Plants perennial; cespitose, with a knotty base composed of very short (less than 1 cm) rhizomes.
Culms

5-65 cm, erect;

nodes glabrous.

50-220 cm, erect;

nodes glabrous or pubescent.

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 1-4(7.7) mm;

blades 12-60 cm long, 2-12 mm wide, flat, mostly glabrous, a few long hairs near the base of the adaxial surface.

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 (4)10-30 racemosely arranged branches;

branches 1.2-11.5 cm, divergent;

branch axes 0.5-1.1 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.

1.8-2.8 mm long, 1.1-1.5 mm wide, paired, appressed to the branch axes, elliptic to slightly obovate, stramineous (rarely 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.

absent;

upper glumes and lower lemmas 3-veined, margins pilose;

upper florets stramineous.

Caryopses

1.9-2.1 mm, yellow.

1.2-1.7 mm, white.

2n

= 20, 30, 40, 48, 60, 61.

= 40.

Paspalum distichum

Paspalum urvillei

Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CA; FL; GA; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX; VA; HI; PR
[WildflowerSearch map]
[BONAP county map]
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 urvillei has been introduced to the United States from South America. In the Flora region it grows in disturbed, moist to wet areas, primarily in the southeastern United States.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 25, p. 575. FNA vol. 25.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Paspalum Poaceae > subfam. Panicoideae > tribe Paniceae > Paspalum
Sibling taxa
P. acuminatum, P. almum, P. bifidum, P. blodgettii, P. boscianum, P. caespitosum, P. conjugatum, P. conspersum, P. convexum, P. coryphaeum, P. dilatatum, P. dissectum, P. fimbriatum, P. floridanum, P. hartwegianum, P. intermedium, P. laeve, P. langei, P. laxum, P. lividum, P. malacophyllum, P. minus, P. modestum, P. monostachyum, P. nicorae, P. notatum, P. paniculatum, P. pleostachyum, P. plicatulum, P. praecox, P. pubiflorum, P. quadrifarium, P. racemosum, P. repens, P. scrobiculatum, P. setaceum, P. unispicatum, P. urvillei, P. vaginatum, P. virgatum, P. virletii, P. wrightii
P. acuminatum, P. almum, P. bifidum, P. blodgettii, P. boscianum, P. caespitosum, P. conjugatum, P. conspersum, P. convexum, P. coryphaeum, P. dilatatum, P. dissectum, P. distichum, P. fimbriatum, P. floridanum, P. hartwegianum, P. intermedium, P. laeve, P. langei, P. laxum, P. lividum, P. malacophyllum, P. minus, P. modestum, P. monostachyum, P. nicorae, P. notatum, P. paniculatum, P. pleostachyum, P. plicatulum, P. praecox, P. pubiflorum, P. quadrifarium, P. racemosum, P. repens, P. scrobiculatum, P. setaceum, P. unispicatum, P. vaginatum, P. virgatum, P. virletii, P. wrightii
Synonyms P. paspaloides
Name authority L. Steud.
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