Eragrostis airoides

Nees
Treatment appears in FNA Volume 25. Treatment on page 103.

Plants perennial; cespitose, with innovations, without rhizomes, not glandular. Culms 30-110 cm, erect, 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. 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. 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. Caryopses 0.4-0.5 mm, ovoid, reticulate, reddish-brown. 2n = 36 (Davidse, pers. comm.).

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Eragrostis airoides"
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Paul M. Peterson +
1 (?) +  and 3 (?) +
multiple +, , +  and single +
not +  and glabrous +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
not projecting +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
0.8 cm8 mm <br />0.008 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
scabridulous +
flat +  and folded +
2mm;4mm +
not disarticulating +
not spikelike +
pubescent +  and glabrous +
reddish-brown +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
branched +, simple +  and rooting +
geniculate +
30 cm300 mm <br />0.3 m <br /> (110 cm1,100 mm <br />1.1 m <br />) +
not woody +
not waisted +
capillary +
pistillate +  and staminate +
sometimes longer +
1 +  and 3 +
round +  and compressed +
reduced +
deciduous +
shorter or longer +
subtending +
lanceolate +  and ovate +
membranous +
uncinate +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
paniculate +  and racemose +
hollow +  and solid +
inconspicuous +
not absent +
(1)3(5)-veined +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
membranous +
sometimes longer +
ciliate +  and ciliolate +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
membranous +
inconspicuous +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
concealed +  and prominent +
2 +  and 1 +
persistent +
2-keeled +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
membranous +
open +  and simple +
18cm +  and 70cm +
3 cm30 mm <br />0.03 m <br /> (25 cm250 mm <br />0.25 m <br />) +
0.24 cm2.4 mm <br />0.0024 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
dry +  and fleshy +
diverging;appressed +
4 cm40 mm <br />0.04 m <br /> (20 cm200 mm <br />0.2 m <br />) +
spikelike +
pilose +  and glabrous +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
1 +  and 60 +
ovate +  and lanceolate +
0.8mm +  and 1.8mm +
1 (?) +  and 3 (?) +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Eragrostis airoides +
Eragrostis +
species +
membranous +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
7 +  and 13 +
rhizomatous +  and stoloniferous +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +  and synoecious +