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

hairyseed paspalum

Habit Plants perennial; rhizomatous or cespitose. Plants perennial; usually decumbent, rooting at the nodes.
Culms

5-65 cm, erect;

nodes glabrous.

30-130 cm, decumbent;

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 1-3.2 mm;

blades to 31 cm long, 4-18 mm wide, flat, glabrous, with a few hairs behind the ligules.

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 2-7 racemosely arranged branches;

branches 2.2-7.9 cm, divergent to spreading, terminating in a spikelet;

branch axes 1.1-2.3 mm wide, narrowly winged, glabrous, margins scabrous.

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.

2.8-3.6 mm long, 1.5-2 mm wide, paired, imbricate, appressed to divergent from the branch axes, elliptic to obovate, pubescent or glabrous, light brown to stramineous.

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 or sparsely pubescent, hairs shorter than 0.1 mm, 3-veined, margins entire;

lower lemmas lacking ribs over the veins;

upper florets stramineous.

Caryopses

1.9-2.1 mm, yellow.

1.8-2 mm, golden brown or white.

2n

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

= 60, ca. 64.

Paspalum distichum

Paspalum pubiflorum

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; CO; DC; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; OH; OK; PA; SC; TN; TX; VA; WV
[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 pubiflorum grows on the edges of forests and in disturbed areas. It is native to the southeastern United States, Mexico, and Cuba.

(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
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. quadrifarium, P. racemosum, P. repens, P. scrobiculatum, P. setaceum, P. unispicatum, P. urvillei, P. vaginatum, P. virgatum, P. virletii, P. wrightii
Synonyms P. paspaloides P. pubiflorum var. glabrum, P. geminum
Name authority L. Rupr. ex E. Fourn.
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