Eustachys retusa
Eustachys
Argentine fingergrass
fingergrass
30-80 cm, erect, or decumbent and rooting at the nodes.
20-150 cm, erect or decumbent, flattened, glabrous;
internodes hollow.
basal and cauline;
sheaths open, keeled, strongly compressed, distinctly distichous, equitant;
ligules to 0.5 mm, scarious, densely short ciliate;
blades flat or folded, erect to spreading, both surfaces usually glabrous, sometimes scabrous or scabridulous.
6-12 cm long, 5-10 mm wide, usually folded, apices obtuse.
with (6)8-15 branches;
branches 4-10 cm, straight, somewhat stiff.
terminal, exceeding the upper leaves, panicles of 1-36 non-disarticulating spikelike branches;
branches digitately arranged, axes triquetrous, with spikelets in 2 rows on the abaxial sides of the branches.
1.5-2.1 mm;
florets 2.
solitary, diverging strongly from the branch axes, laterally compressed, sessile or subsessile, with 2-3 florets;
lowest florets bisexual;
second florets usually reduced to a stipitate empty lemma, occasionally with a palea, staminate if a third floret is present;
third florets, if present, sterile and usually rudimentary, stipitate;
disarticulation above the glumes.
unequal, 1-veined;
lower glumes somewhat smaller than the upper glumes, narrow, acuminate;
upper glumes almost as long as the spikelets, flattened, scarious, glabrous, green, pale, or purplish, veins antrorsely scabrous, apices truncate, bilobed, or bifid, often mucronate;
lowest lemmas cartilaginous, light to dark brown, scabridulous distally, 3-veined, unawned, mucronate, or with a single awn, awns to 1.2 mm;
paleas equaling or slightly shorter than the lemmas, glabrous, 2-veined, veins keeled, shortly ciliate or scabridulous;
anthers 3, deep purple to purple-red.
1.1-1.3 mm, linear-lanceolate, acute;
upper glumes 1.3-1.5 mm, oblanceolate, apices truncate or bilobed, mucronate, mucros to 0.4 mm;
calluses with a few short hairs;
lowest lemmas 1.7-2 mm, lanceolate to ovate, not strongly keeled, midveins glabrous, lateral veins with widely spreading, white, 1-2 mm hairs, apices acute to mucronate;
second lemmas 1.1-1.2 mm, broadly cuneate, apices truncate.
about 1 mm.
1-1.7 mm, trigonous-ellipsoid, glabrous, translucent when fresh, pale to slightly reddish-purple-tinged, x = 10.
= 40.
Eustachys retusa
Eustachys
Eustachys retusa is native to South America, but it is now established along roadsides, sandy fields, and waste areas in the southeastern United States.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Eustachys, as treated here, is a genus of approximately 12 species, most of which are native to the Western Hemisphere; four are native to the Flora region and three have been introduced. It is, in many ways, morphologically similar to Chloris, with the placement of a few species being problematic. Molecular data (Alice et al. 2000) support its recognition as a distinct genus, but the relationships between it, Chloris sensu stricto, and Cynodon are not clear.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lateral veins of the lowest lemma in each spikelet usually glabrous, occasionally with a few short, stiff hairs | E. glauca |
1. Lateral veins of the lowest lemma in each spikelet pubescent. | → 2 |
2. Keels of the lowest lemma in each spikelet glabrous. | → 3 |
3. Spikelets 1.5-2.1 mm long; panicles with 6-15 branches; branches 4-10 cm long, straight, somewhat stiff; leaf blades 5-10 mm wide | E. retusa |
3. Spikelets 2.4-3 mm long; panicles with 10-36 branches; branches 6-15 cm long, flexible; leaf blades 10-15 mm wide | E. distichophylla |
2. Keels of the lowest lemma in each spikelet pubescent. | → 4 |
4. Spikelets 1.5-2.5 mm long; lowest lemma in each spikelet mucronate. | → 5 |
5. Lowest lemma in each spikelet dark brown, the lateral veins with appressed hairs shorter than 0.5 mm | E. petraea |
5. Lowest lemma in each spikelet tawny to reddish-brown, the lateral veins with spreading hairs longer than 0.5 mm | E. caribaea |
4. Spikelets 2.6-3.7 mm long; lowest lemma in each spikelet awned, awns 0.4-1.2 mm. | → 6 |
6. Panicle branches 1-3; awns of lowest lemma in each spikelet 0.4-0.6 mm long; spikelets 3-3.7 mm long | E. floridana |
6. Panicle branches (3)4-9; awns of lowest lemma in each spikelet 0.7-1.2 mm long; spikelets 2.6-3 mm long | E. neglecta |
WildflowerSearch
iNaturalist
USDA Plants Database
LA Plants
