Eragrostis airoides |
Eragrostis japonica |
|
---|---|---|
darnel lovegrass |
pond lovegrass |
|
Habit | Plants perennial; cespitose, with innovations, without rhizomes, not glandular. | Plants annual; cespitose, without innovations, without glands. |
Culms | 30-110 cm, erect, glabrous below the nodes. |
25-100(115) cm, erect or geniculate, lower portion glabrous and shiny. |
Sheaths | glabrous or pilose, hairs to 5 mm; ligules 0.1-0.2 mm; blades 8-22 mm long, (1)2-4(5) mm wide, flat to folded, glabrous abaxially, scabridulous adaxially. |
glabrous at the apices and on the upper margins; ligules 0.4-0.6 mm, scarious, glabrous; blades (4)15-20(25) cm long, 1.5-6 mm wide, flat, sometimes auriculate, abaxial surfaces glabrous, smooth, adaxial surfaces scabridulous, Panicles 15-40 cm long, 0.8-5 cm wide, lanceoloid, contracted, interrupted near the base; primary branches 2-10 cm, appressed or diverging to 30° from the rachises, spikelet-bearing to near the base; pulvini glabrous; pedicels 0.5-1.5 mm, sinuous. |
Panicles | 18-70 cm long, 3-25 cm wide, diffuse, ovate; primary branches 4-20 cm, appressed or diverging 10-70° from the rachises, naked basally; pulvini glabrous; pedicels 2.4-11 mm, divergent. |
|
Spikelets | 1.3-2 mm long, 0.8-1.8 mm wide, ovate to lanceolate, plumbeous, with 1-3 florets; disarticulation acropetal, in the rachilla below the florets, glumes deciduous; rachilla prolonged above the terminal floret. |
2.2-3.8 mm long, 0.8-1.3 mm wide, oblong to narrowly lanceolate, yellowish-brown to whitish and hyaline, with 4-12 florets; disarticulation basipetal, rachillas and glumes persistent. |
Glumes | lanceolate to ovate, membranous; lower glumes 0.8-1 mm; upper glumes 1.1-1.4 mm; lemmas 0.8-1.2 mm, ovate, membranous, plumbeous, keels and lateral veins inconspicuous, apices obtuse; paleas 0.8-1.2 mm, membranous, bases not projecting beyond the lemmas, apices obtuse; anthers 3, 0.3-0.5 mm, purplish. |
subequal, 0.6-1 mm, ovate to ovate-lanceolate, hyaline; upper glumes without a midvein; lemmas 0.9-1.2 mm, ovate, hyaline, lateral veins conspicuous basally, greenish, apices acute; paleas 0.6-0.8 mm, hyaline, keels smooth basally, scabridulous distally, apices acute, often bifid; anthers 2, 0.1-0.2 mm, whitish to light brown. |
Caryopses | 0.4-0.5 mm, ovoid, reticulate, reddish-brown. |
0.3-0.4 mm, obovoid, smooth, reddish-brown. |
Comm | .). |
|
2n | = 36 (Davidse, pers. |
= 20. |
Eragrostis airoides |
Eragrostis japonica |
|
Distribution |
TX |
AL; AR; FL; GA; IL; LA; MO; MS; OK; SC; TN; TX |
Discussion | Eragrostis airoides is a South American species that, in the Flora region, is known only from roadsides and disturbed sites in Brazos County, Texas. It is an enigmatic species, often treated as Sporobolus brasiliensis (Raddi) Hack., which it resembles in its chromosome base number of x = 9 and caryopsis morphology, but its frequent possession of spikelets with more than 1 floret and its mode of spikelet disarticulation argue for its retention in Eragrostis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eragrostis japonica is native to the tropics of the Eastern Hemisphere; it is now established in moist areas along rivers and streams in the southern portion of the contiguous United States, usually in sandy soils, at 0-200 m. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 103. | FNA vol. 25, p. 74. |
Parent taxa | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Eragrostis | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Eragrostis |
Sibling taxa | ||
Synonyms | E. glomerata | |
Name authority | Nees | (Thunb.) Trin. |
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