Eragrostis airoides |
Eragrostis palmeri |
|
---|---|---|
darnel lovegrass |
Rio Grande lovegrass |
|
Habit | Plants perennial; cespitose, with innovations, without rhizomes, not glandular. | Plants perennial; cespitose, with innovations and knotty bases, without rhizomes, not glandular. |
Culms | 30-110 cm, erect, glabrous below the nodes. |
50-90(120) cm, glabrous below the nodes. |
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. |
villous and the hairs not papillose-based, or mostly glabrous, apices hairy, hairs to 5 mm, not papillose-based; ligules 0.2-0.4 mm; blades (14)20-35 cm long, 1-2.4 mm wide, involute, abaxial surfaces glabrous, adaxial surfaces scabridulous, sometimes sparsely hairy. |
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. |
12-40 cm long, 4-20 cm wide, oblong, open; primary branches 2-20 cm, diverging 20-70° from the rachises, capillary; pulvini glabrous or sparsely hairy; pedicels (0.4)1-4(14) mm, appressed or diverging, only the terminal pedicels on each branch longer than 4 mm. |
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. |
4-6(7.3) mm long, 1-2 mm wide, linear-lanceolate, plumbeous, with 5-12 florets; disarticulation acropetal, paleas 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. |
lanceolate to ovate, hyaline; lower glumes 1.1-1.8 mm; upper glumes 1.2-2.2 mm, exceeded by the basal lemmas; lemmas 2-2.6 mm, ovate, membranous, hyaline towards the apices and margins, keels weak or strong, without glands, lateral veins from inconspicuous to conspicuous, apices acute; paleas 1.7-2.4 mm, hyaline, bases not projecting beyond the lemmas, apices truncate, often notched; anthers 3, 0.6-1.3 mm, yellowish to purplish. |
Caryopses | 0.4-0.5 mm, ovoid, reticulate, reddish-brown. |
0.6-0.8 mm, rectangular-prismatic to subellipsoid, laterally compressed, with a well-developed adaxial groove, faintly striate, opaque, reddish-brown. |
Comm | .). |
|
2n | = 36 (Davidse, pers. |
= 40. |
Eragrostis airoides |
Eragrostis palmeri |
|
Distribution |
TX |
NM; 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 palmeri grows on rocky slopes and hills between 300-2150 m, generally in association with Pinus edulis, Juniperus monosperma, Bouteloua gracilis, and Prosopis. Its range extends from the southwestern United States into Mexico. It resembles E. erosa, but differs in its shorter lemmas and caryopses. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 103. | FNA vol. 25, p. 93. |
Parent taxa | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Eragrostis | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Eragrostis |
Sibling taxa | ||
Name authority | Nees | S. Watson |
Web links |