Echinochloa polystachya

(Kunth) Hitchc.
Common names: Creeping river grass
Treatment appears in FNA Volume 25. Treatment on page 394.

Plants perennial; not rhizomatous. Culms 1-2 m tall, to 1 cm thick, erect or decumbent and rooting at the lower nodes, upper portion sometimes floating distally; nodes glabrous or antrorsely villous. Sheaths mostly glabrous, minutely puberulent, or hispid, hairs papillose-based, throat hispid; ligules present on the lower leaves, 1-5 mm, of stiff hairs; blades 15-70 cm long, 5-13 mm wide, glabrous. Panicles 13-45 cm, erect, rachis nodes hispid, hairs 3-6.5 mm, papillose-based, internodes scabrous; primary branches 4-10 cm, subverticillate, ascending, nodes hispid, hairs 2.5-4 mm, papillose-based, internodes scabrous; secondary branches short, spikelets subsessile, in clusters. Spikelets 4-7 mm, hispid, hairs appressed, disarticulating at maturity. Lower glumes at least 1/2 as long as the spikelets; lower florets staminate; lower lemmas apiculate or awned, awns to 18 mm; lower paleas subequal to the lower lemmas, often purple; anthers of lower florets 1.5-3.6 mm, orange; upper lemmas 2.5-5 mm, elliptic or narrowly ovate, apices obtuse, with a membranous, soon-withering tip; anthers of upper florets shorter than those of the lower florets. Caryopses to 3 mm. 2n = 54.

Distribution

Puerto Rico, Fla., Tex., La.

Discussion

Echinochloa polystachya grows in coastal marshes, often in standing water, from Texas, Louisiana, and Florida south through Mexico and the Caribbean islands to Argentina. Two varieties exist. Echinochloa polystachya var. polystachya has glabrous culms and leaf sheaths; Echinochloa polystachya var. spectabilis (Nees ex Trin.) Mart. Crov. has swollen, pubescent cauline nodes and pubescent leaf sheaths.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Echinochloa polystachya"
membranous +  and firm +
anatomy +  and kranz +
P.W. Michael +
(Kunth) Hitchc. +
1 (?) +  and 3 (?) +
0 cm0 mm <br />0 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
15 cm150 mm <br />0.15 m <br /> (70 cm700 mm <br />0.7 m <br />) +
linear +  and linear-lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
subsessile +, compound +  and simple +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
spheroid +, ovoid +  and ellipsoid +
0 cm0 mm <br />0 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
sometimes longer +
Creeping river grass +
100 cm1,000 mm <br />1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
decumbent +  and erect +
10 cm100 mm <br />0.1 m <br /> (460 cm4,600 mm <br />4.6 m <br />) +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Puerto Rico +, Fla. +, Tex. +  and La. +
0.7-0.9 times as long as the caryopses +
capillary +
germination +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
disarticulating +  and papillose-based +
uncinate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
bracteate +  and ebracteate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
membranous +
inconspicuous +
awned +  and apiculate +
complex +  and simple +
concealed +  and prominent +
hispid +, villous +  and glabrous +
2 +  and 1 +
subterranean +
13 cm130 mm <br />0.13 m <br /> (45 cm450 mm <br />0.45 m <br />) +
dry +  and fleshy +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
elongate +
hispid +, puberulent +  and glabrous +
compressed +
in triplets +  and paired +
1 +  and 60 +
unisexual +  and bisexual +
planoconvex +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Echinochloa polystachya +
Echinochloa +
species +
soon-withering +
membranous +
membranous +
ovate +  and elliptic +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +