25.14   ERIOCHLOA Kunth
Robert B. Shaw
Robert D. Webster
Christine M. Bern

Plants annual or perennial; cespitose, sometimes with short rhizomes or stolons, not producing subterranean spikelets. Culms 20-250 cm, erect or decumbent, usually with 2-5 nodes. Sheaths open; auricles absent; ligules membranous, ciliate. Inflorescences terminal, panicles of spikelike branches on elongate rachises; branches with many pedicellate, loosely appressed spikelets, terminating in a spikelet, without stiff bristles or flat bracts, spikelets in pairs, triplets, or solitary, often solitary distally when in pairs or triplets at the middle of the branches; pedicels terminating in a well-developed disk; disarticulation below the glume(s). Spikelets with 2 florets, lower florets usually sterile, upper florets bisexual. Lower glumes typically reduced (sometimes absent) and fused with the glabrous callus to form a cuplike structure; upper glumes lanceolate to ovate, glabrous or variously pubescent, 3-9-veined, unawned or awned; lower lemmas similar to the upper glumes in length, shape, venation, and pubescence, unawned; lower paleas absent to fully developed; upper lemmas lanceolate to ovate, indurate, rugose, dull, glabrous, rounded on the back, veins not pronounced, margins involute; anthers 3; lodicules 2, papery; styles with 2 branches, purple, plumose. Caryopses not longitudinally grooved; endosperm solid. x = 9. Name from the Greek erion, wool, and chloe, grass, a reference to the usually pubescent pedicels and rachises.

Eriochloa, a genus of 20-30 species, grows in tropical, subtropical, and warm-temperate areas of the world. Eight species of Eriochloa are native to the Flora region and three are introduced. Of the three introduced species only two, E. polystachya and E. pseudoacrotricha, have become naturalized.

Only one native species, Eriochloa sericea, is abundant enough to be an important forage species. The introduced E. polystachya is also used for for this purpose.


SELECTED REFERENCES Shaw, R.B. and F.E. Smeins. 1981. Some anatomical and morphological characteristics of the North American species of Eriochloa (Poaceae: Paniceae). Bot. Gaz. 142:534-544; Shaw, R.B. and R.D. Webster. 1987. The genus Eriochloa (Poaceae: Paniceae) in North and Central America. Sida 12:165-207.

1
Spikelets solitary at the middle of the branches, sometimes in unequally pedicellate pairs near the base (2)
Spikelets in unequally pedicellate pairs or triplets at the middle of the branches, sometimes solitary distally (6)
2
Pedicels with more than 12 long (1.5-3 mm) hairs near the apices, densely hirsute or villous below, the hairs mostly about 0.1 mm long, but with some longer hairs interspersed among the short hairs (3)
Pedicels with fewer than 10 long (1.5-3 mm) hairs near the apices; variously hirsute below (4)
3
Blades 0.5-4 mm wide; spikelets 1.4-1.9 mm wide; plants perennial ..... 1. E. sericea
Blades 5-12 mm wide; spikelets 2-2.5 mm wide; plants annual ..... 2. E. villosa
4
Lower floret of each spikelet with a palea ..... 3. E. michauxii
Lower floret of each spikelet without a palea (5)
5
Rachises hairy, the longer hairs 0.1-0.8 mm long; spikelets 3.1-5 mm long, 1.2-1.7 mm wide ..... 4. E. contracta
Rachises glabrous or scabrous, not hairy; spikelets 2.7-3.6 mm long, 0.8-1.5 mm wide ..... 5. E. fatmensis
6
Adaxial surfaces of the blades velvety to the touch; cauline internodes pubescent to pilose ..... 6. E. lemmonii
Adaxial surfaces of the blades glabrous or hairy, but not velvety to the touch; cauline internodes glabrous or pubescent (7)
7
Upper lemmas unawned or the awns shorter than 0.2(0.3) mm (8)
Upper lemmas awned, the awns 0.2-1.5 mm long (11)
8
Plants annual; upper glumes acute to acuminate, often terminating in awnlike apices up to 1.5 mm long; lower florets without paleas (9)
Plants perennial; upper glumes acute, unawned; lower floret of each spikelet usually with a palea (10)
9
Longer pedicels of the spikelet pairs or triplets to 1 mm long; upper glumes acute to acuminate, unawned or awned, the awns up to 1.2 mm long ..... 10. E. acuminata
Longer pedicels of the spikelet pairs to 3 mm long; upper glumes always acuminate, awned, the awns 0.5-3.5 mm long ..... 8. E. aristata
10
Culms erect, not rooting at the lower nodes; spikelets 3.7-5.7 mm long, 1.3-1.8 mm wide; lower floret of each spikelet always with a palea ..... 3. E. michauxii
Culms decumbent, rooting at the lower nodes; spikelets 3.2-3.9 mm long, 1.1-1.3 mm wide; lower floret of each spikelet with or without a palea ..... 11. E. polystachya
11
Spikelets 2.7-3.6 mm long, 0.8-1.5 mm wide ..... 5. E. fatmensis
Spikelets 3.6-8.8 mm long, 0.9-1.6 mm wide (12)
12
Pedicels uniformly hirsute, the hairs about 0.1 mm long; plants rhizomatous ..... 7. E. punctata
Pedicels with some hairs 0.5-2.5 mm long, at least distally; plants not rhizomatous (13)
13
Plants perennial ..... 9. E. pseudoacrotricha
Plants annual (14)
14
Longer pedicels of the spikelet pairs or triplets to 1 mm long; upper glumes acute to acuminate, unawned or awned, the awns up to 1.2 mm long ..... 10. E. acuminata
Longer pedicels of the spikelet pairs to 3 mm long; upper glumes always acuminate, awned, the awns 0.5-3.5 mm long ..... 8. E. aristata


1.   Eriochloa sericea (Scheele) Munro ex Vasey
Texas Cupgrass

Plants perennial; cespitose, shortly rhizomatous. Culms 30-130 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes pubescent; nodes puberulent to densely pubescent. Sheaths 3-14 cm, not overlapping, frequently inflated or spreading from the culm, chartaceous, glabrous or pubescent; ligules 0.5-1.5 mm, densely ciliate; blades 10-30 cm long, 0.5-4 mm wide, filiform to linear, involute to flat, straight or lax, appressed to divergent, glabrous or with soft pubescence. Panicles 4-20 cm long, 0.5-1.5 cm wide, contracted; rachises pilose or villous; branches (2)4-8(10), 10-35 mm long, 0.4-0.7 mm wide, velutinous, sometimes winged, with 10-20 solitary spikelets; pedicels 0.4-0.7 mm, densely hirsute with a mixture of short and long hairs, apices with more than 12 hairs of 1.5-2.5 mm. Spikelets 4-5 mm long, 1.4-1.9 mm wide. Lower glumes absent; upper glumes appressed pubescent, ovate to elliptic, 5-7-veined, acute, unawned; lower lemmas 3.8-4.8 mm long, 1.5-1.9 mm wide, indurate, elliptic, pubescent to velutinous, 5-7-veined, acute, unawned; lower paleas absent; anthers absent; upper lemmas 2.7-3.6 mm, elliptic, acute, shortly awned, awns 0.1-0.2 mm; upper paleas slightly shorter than the lemmas, indurate, minutely rugose. 2n =54.

Eriochloa sericea usually grows on clay or clay-loam soils in prairies, roadsides, or protected areas. It is widespread in the blackland prairie and Edwards Plateau of Texas, but extends into Kansas, Nebraska, and Oklahoma, and onto the coastal prairie and rolling plains of Texas and northern Mexico.


2.   Eriochloa villosa (Thunb.) Kunth
Ériochloé Velue

Plants annual. Culms 30-100 cm, erect or decumbent, sometimes rooting at the lower nodes; nodes and internodes pubescent. Sheaths sometimes inflated, glabrous or pubescent; ligules 0.5-1 mm; blades 10-20 cm long, 5-12 mm wide, flat, adaxial surfaces hairy. Panicles 3-16 cm long, 1-3 cm wide; rachises villous; branches 2-8, 20-70 mm long, 0.8-1.1 mm wide, velutinous, sometimes winged, with 11-24 solitary spikelets (occasionally paired proximally); pedicels 0.5-1 mm, densely villous below, often with long hairs intermixed with the short hairs, apices with more than 12 hairs of 1.5-2.5 mm. Spikelets 3.9-5.2 mm long, 2-2.5 mm wide, ovate to elliptic. Lower glumes occasionally present as a scale; upper glumes equaling the lower lemmas, ovate to elliptic, glabrous or pubescent, 7-veined; lower lemmas 3.4-5 mm long, 2-2.5 mm wide, 5-veined, acute to apiculate, unawned; lower paleas absent; anthers absent; upper lemmas 3.5-5 mm, ovate to elliptic, acute to apiculate. 2n = 54.

Eriochloa villosa is a weedy species of eastern Asia that has been found at scattered locations in the Flora region


3.   Eriochloa michauxii (Poir.) Hitchc.
Longleaf Cupgrass

Plants perennial; cespitose and rhizomatous. Culms 50-250 cm, erect, not rooting at the lower nodes; internodes glabrous; nodes 3-7, puberulent to appressed pilose, rarely glabrous. Sheaths glabrous; collars hairy; ligules 0.5-1.5 mm; blades 10-60 cm long, 5-15 mm wide, linear, flat to conduplicate, straight or lax, spreading, glabrous adaxially. Panicles 10-30 cm long, 2.5-10 cm wide, open or contracted; rachises villous or puberulent; branches 10-25, 15-60 mm long, 0.5-0.8 mm wide, appressed to spreading, villous to shortly pilose, rarely puberulent or scabrous, not winged, with 16-40 spikelets on the primary branches, spikelets in unequally pedicellate pairs or triplets proximally, solitary distally; pedicels 0.3-2.5 mm, variously hirsute below, with fewer than 10 hairs more than 0.5 mm long at the apices. Spikelets 3.7-5.7 mm long, 1.3-1.8 mm wide, ovate to elliptic. Upper glumes equaling the lower lemmas, ovate, hairy, 5-veined, acute, unawned, rarely mucronate; lower lemmas 3.5-5 mm long, 1.3-1.8 mm wide, ovate to elliptic, setose, 5(7)-veined, acute, unawned; lower paleas fully developed, as long as or longer than the lemmas, hyaline; anthers 3 or absent; upper lemmas 3.1-4.6 mm, indurate, elliptic, 5-veined, acute to rounded, mucronate or awned, awns 0.1-0.6 mm; upper paleas 3-4.3 mm, indurate, blunt. 2n = 36.

Eriochloa michauxii is endemic to the southeastern United States. There are two varieties, differing as shown in the following key. Intermediate plants have been collected in Lee and Monroe counties, Florida.

1
Lower florets staminate; blades generally flat, usually 8-15 mm wide ..... var. michauxii
Lower floret sterile; blades involute to conduplicate, 5-8 mm wide ..... var. simpsonii


Eriochloa michauxii (Poir.) Hitchc. var. michauxii grows in brackish or fresh water marshes, hammocks, and prairies of the southeastern United States, including the whole of Florida.


Eriochloa michauxii var. simpsonii (Hitchc.) Hitchc. is a rare variety that grows in low wet areas, roadsides, or on washed sand and shell beaches of southwestern Florida.


4.   Eriochloa contracta Hitchc.
Prairie Cupgrass

Plants annual; cespitose. Culms 20-100 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes pilose or pubescent; nodes pubescent to puberulent. Sheaths sparsely to densely pubescent; ligules 0.4-1.1 mm; blades 6-12(22) cm long, 2-8 mm wide, linear, flat to conduplicate, straight, appressed to divergent, both surfaces sparsely to densely pubescent with short, evenly spaced hairs. Panicles 6-20 cm long, 0.3-1.2 cm wide; rachises pilose, longer hairs 0.1-0.8 mm; branches 10-20(28), 15-45(60) mm long, 0.2-0.4 mm wide, appressed, pubescent to setose, not winged, with 8-16 mostly solitary spikelets, occasionally paired at the base of the branches; pedicels 0.2-1 mm, variously hirsute below, apices with fewer than 10 hairs more than 0.5 mm long. Spikelets (3.1)3.5-4.5(5) mm long, 1.2-1.7 mm wide, lanceolate. Upper glumes as long as the lower lemmas, with sparsely appressed pubescence on the lower 2/3, scabrous or glabrous distally, 3-9-veined, acuminate and awned, awns 0.4-1 mm; lower florets sterile; lower lemmas 3-4.3 mm long, 1.2-1.7 mm wide, lanceolate, setose, 3-7-veined, acuminate, unawned or mucronate; lower paleas absent; upper lemmas 2-2.5 mm, indurate, elliptic, 5-7-veined, acute to rounded and awned, awns 0.4-1.1 mm; upper paleas indurate, faintly rugose, blunt. 2n = 36.

Eriochloa contracta grows in fields, ditches, and other disturbed areas. It is known only from the United States, being native and common in the central United States, and adventive to the east and southwest. It differs from E. acuminata in its tightly contracted, almost cylindrical panicles and longer lemma awns, but intermediate forms can be found. It can also be confused with first-year plants of the perennial E. punctata, which have glabrous leaves, narrower and more tapering spikelets, and longer lemma awns.


5.   Eriochloa fatmensis (Hochst. & Steud.) Clayton

Plants annual. Culms 30-120 cm, erect or decumbent, sometimes rooting at the lower nodes; nodes and internodes glabrous. Sheaths smooth, glabrous; ligules 0.5-1 mm; blades 6-40 cm long, 3-8 mm wide, linear, flat to involute, glabrous adaxially. Panicles 6-18 cm long, 0.8-3 cm wide; rachises smooth or scabrous; branches 3-10, 25-60 mm long, 0.4-0.6 mm wide, sometimes winged, glabrous, with 20-40 spikelets, spikelets solitary or in unequally pedicellate pairs at the middle of the branches; pedicels 0.2-0.8 mm, glabrous or hairy below, apices with fewer than 10 hairs to 0.5 mm long. Spikelets 2.7-3.6 mm long, 0.8-1.5 mm wide, lanceolate. Upper glumes 1.1-1.3 times longer than the lower lemmas, hairy, 5-veined, apices acuminate and acute to awned, awns 0.3-1.5 mm; lower lemmas 2.5-3.3 mm long, 0.8-1 mm wide, setose, apices acuminate and mucronate; lower paleas absent; anthers absent; upper lemmas 1.7-2.2 mm, elliptic, acute to rounded, awned, awns 0.2-0.5 mm. 2n = unknown.

Eriochloa fatmensis is native to tropical Africa, Arabia, and India, where it usually grows in wet areas or grasslands. It has been found in Tucson, Arizona, and Biloxi, Mississippi, but is probably not established in the Flora region.


6.   Eriochloa lemmonii Vasey & Scribn.
Canyon Cupgrass

Plants annual; cespitose. Culms 20-80 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes densely pubescent to pilose; nodes pubescent to pilose. Sheaths from conspicuously inflated to not inflated, glabrous or pubescent to pilose; ligules 0.5-1 mm; blades 5-15 cm long, 6-20 mm wide, lanceolate, flat, straight, diverging or ascending, velvety pubescent adaxially. Panicles 5-15 cm long, 0.5-4 cm wide, spreading or contracted; rachises hairy; branches (2)3-8(10), 1-4 cm long, 0.4-0.6 mm wide, appressed or reflexed and spreading, velvety pubescent, not winged, with 10-14 spikelets, spikelets in unequally pedicellate pairs at the middle of the branches, solitary distally; pedicels 0.5-1 mm, pilose, apices hairy or glabrous. Spikelets 3-4.5(4.9) mm long, 1.2-1.7 mm wide, elliptic. Upper glumes equaling the lower lemmas, nearly glabrous or sparsely to densely pilose, elliptic, 5-7-veined, acute, unawned; lower lemmas 2.7-4 mm long, 1.2-1.7 mm wide, elliptic, setose to pilose, 5-veined, acute, unawned; lower paleas 1-4 mm, hyaline; anthers absent or 3; upper lemmas 2.3-3.3 mm, elliptic, indurate, dull, rough, occasionally with a few long hairs, acute to rounded, sometimes mucronate; upper paleas indurate. 2n = 36.

Eriochloa lemmonii, a rare species, grows in canyons and on rocky slopes in Pima County, Arizona, Hidalgo County, New Mexico, and adjacent Mexico. The record from Tennessee reflects an introduction. It is not known if the species has persisted in the region.

Eriochloa lemmonii may hybridize with E. acuminata, from which it differs in the frequent presence of lower paleas, raised veins of the upper glumes and lower lemmas, broad, velvety pubescent leaf blades, and blunt spikelets. Reports of E. lemmonii from Texas may be based on hybrids between the two species.


7.   Eriochloa punctata (L.) Desv. ex Ham.
Louisiana Cupgrass

Plants perennial; rhizomatous, often flowering the first year and resembling an annual. Culms 30-150 cm, erect or decumbent, not rooting at the lower nodes; internodes glabrous; nodes 3-10, glabrate. Sheaths occasionally inflated, glabrous (rarely puberulent), often purplish at maturity; ligules 0.4-1 mm; blades 10-50 cm long, (2)4-10(13) mm wide, linear, flat, straight, spreading, glabrous (rarely puberulent) on both surfaces. Panicles 9-22 cm long, 1-10 cm wide, contracted, rarely open; rachises scabrous to densely pubescent; branches (4)8-20(27), 1-6 cm long, 0.3-0.5 mm wide, appressed or divergent, glabrous, not winged, with 28-60 spikelets, spikelets mostly in unequally pedicellate pairs, solitary distally; pedicels 0.1-0.7 mm, uniformly pubescent, hairs about 0.1 mm. Spikelets (4)4.5-5.7 mm long, 0.9-1.4 mm wide. Upper glumes equaling the lower lemmas, lanceolate, sparsely appressed pilose, 5-7-veined, acuminate, sometimes mucronate, mucro shorter than 0.5 mm; lower lemmas 4.3-5.5 mm long, 0.9-1.4 mm wide, lanceolate, setose, 5-7-veined, acuminate, unawned or mucronate; lower paleas absent; anthers absent; upper lemmas 2-3.5 mm (excluding the awn), 0.4-0.6 times as long as the lower lemmas, indurate, elliptic, 5-veined, rounded, awned, awns 0.6-1.5 mm; upper paleas 0.5-1.2 mm, indurate, blunt. 2n = 36.

Eriochloa punctata grows in coastal marshes, along water courses, and in moist swales and ditches of the coastal plain from Texas and Louisiana south through Mexico to Central and South America. It has not been possible to verify the identification of the specimen from Georgia for this treatment. If correct, it suggests that the species may be more widespread than generally thought.


8.   Eriochloa aristata Vasey
Bearded Cupgrass

Plants annual; cespitose, not rhizomatous. Culms 40-100 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes glabrous; nodes 3-10, puberulent. Sheaths glabrous; ligules 0.5-0.8(2) mm; blades 6-20 cm long, 6-20 mm wide, linear to lanceolate, flat or folded, straight or lax, glabrous (rarely sparsely pubescent) adaxially. Panicles 5-20 cm long, 1-3 cm wide, loosely contracted; rachises hairy; branches 16-30, 20-35 mm long, 0.3-0.5 mm wide, divergent to spreading, setose, not winged, with 20-35 spikelets in unequally pedicellate pairs; pedicels 0.5-3 mm, hairy, with some hairs 0.5-2.5 mm long, at least distally. Spikelets 4-8.8 mm long, 1.1-1.6 mm wide, lanceolate. Upper glumes 1-1.1 times as long as the lower lemmas, lanceolate, pilose or scabrous above, 5-veined, acuminate and awned, awns 0.5-3.5 mm; lower florets sterile; lower lemmas 4-8 mm long, 1.1-1.6 mm wide, lanceolate, setose, 3-7-veined, acuminate, mucronate, mucro less than 0.4 mm; lower paleas absent; anthers absent; upper lemmas (2)3-4(6) mm, 0.4-0.6 times as long as the lower lemmas, indurate, elliptic, acute to rounded, 5-veined, awned, awns 0.2-0.8 mm; upper paleas indurate, rugose. 2n = 36.

Eriochloa aristata is a weed of moist swales, roadsides, and irrigated fields of the southwestern United States. Its range extends through Mexico and Central America to Colombia. There are three specimens from Oktibbeha County, Mississippi, two made in 1890 and one made in 1960. The last collection was from a waste area, which suggests that the species is not established there. The other two were both made in Starkville, where there is an experimental farm. The labels on the two specimens do not state whether the collections were made from experimental plantings or from plants that had escaped from such plantings.


9.   Eriochloa pseudoacrotricha (Stapf ex Thell.) J.M. Black
Vernal Cupgrass

Plants perennial; cespitose, not rhizomatous. Culms 40-80 cm, erect, not rooting at the lower nodes; internodes glabrous; nodes hairy. Sheaths glabrous, rarely with a few appressed hairs; collars glabrous; ligules 0.4-1 mm; blades 10-20 cm long, 2-4 mm wide, linear, flat, straight, spreading, glabrous or hairy adaxially. Panicles 5-15 cm long, 0.3-1 cm wide; rachises scabrous; branches 2-8, 25-45 mm long, 0.3-0.6 mm wide, divergent to spreading, glabrous, winged, with 2-40 spikelets in unequally pedicellate pairs at the middle of the branches; pedicels 1-3 mm, glabrous, apices hairy. Spikelets 3.6-5.4 mm long, 1.1-1.4 mm wide, lanceolate. Upper glumes 1-1.3 times as long as the lower lemmas, lanceolate, hairy, 5-veined, acuminate, awned, awns 0.5-1.5 mm; lower florets sterile; lower lemmas 3.5-5.2 mm long, 1.1-1.4 mm wide, lanceolate, setose, 5-veined, mucronate to awned; lower paleas absent; upper lemmas 2.1-3.7 mm, elliptic, apices rounded, awned, awns 0.4-0.8 mm; upper paleas indurate, blunt, not rugose. 2n = 36.

Eriochloa pseudoacrotricha is an Australian species that has been introduced into south Texas and Mississippi. It grows in waste areas.


10.   Eriochloa acuminata (J. Presl) Kunth
Southwestern Cupgrass

Plants annual; cespitose. Culms 30-120 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes glabrous or with scattered hairs; nodes glabrous or pilose. Sheaths sometimes conspicuously inflated, glabrous or pubescent; ligules 0.2-1.2 mm; blades 5-12(18) cm long, (2)5-12(16) mm wide, linear, flat or folded, straight or lax, glabrous or sparsely pubescent adaxially. Panicles 7-16 cm long, 1-6 cm wide, loosely contracted; rachises scabrous or hairy; branches 5-20, 1-5 cm long, 0.4-0.6 mm wide, appressed to divergent, pubescent, sometimes setose, not winged, with 20-36 spikelets, spikelets mostly in unequally pedicellate pairs, solitary distally; pedicels 0.1-1 mm, hairy. Spikelets 3.8-5(6) mm long, 1.1-1.4 mm wide, lanceolate to ovate. Lower glumes absent; upper glumes equaling the lower lemmas, lanceolate to ovate, hairy, 5(7)-veined, acuminate to acute, unawned or awned, awns to 1.2 mm; lower lemmas 3.6-5 mm long, 1.1-1.4 mm wide, lanceolate to ovate, setose, 5(7)-veined, acuminate to acute, unawned; lower paleas absent; anthers absent; upper lemmas 2.3-3.3 mm, 0.7-0.9 times as long as the lower lemmas, indurate, elliptic, rounded, 5-veined, awned, the awns 0.1-0.3 mm; upper paleas indurate, blunt, rugose. 2n = 36.

Eriochloa acuminata is native to the southern United States and northern Mexico, but has become established outside this region. It may hybridize with E. lemmonii, from which it differs in its lack of lower paleas, upper glumes and lower lemmas with level veins, and narrower, glabrous or sparsely pubescent leaf blades.

There are two varieties of Eriochloa acuminata, differing as shown in the key below.

1
Spikelets 4-6 mm long, long-acuminate or tapering to a short awn ..... var. acuminata
Spikelets 3.8-4 mm long, acute ..... var. minor


Eriochloa acuminata (J. Presl) Kunth var. acuminata generally grows in ditches, fields, right of ways, and other disturbed areas of the southern United States.


Eriochloa acuminata var. minor (Vasey) R.B. Shaw is common in irrigated fields, orchards and disturbed areas of the southwestern United States. It is adventive in Maryland.


11.   Eriochloa polystachya Kunth
Caribbean Cupgrass

Plants perennial; cespitose, stoloniferous. Culms 100-200 cm, decumbent, rooting at the lower nodes; internodes glabrous; nodes 4-10, densely pilose. Sheaths chartaceous to cartilaginous, lower sheaths with papillose-based hairs, upper sheaths glabrous; collars hairy; ligules 0.6-1.2 mm; blades 6-28 cm long, 6-18 mm wide, linear, flat, straight, ascending or drooping, glabrous adaxially. Panicles 8-20 cm long, 41-90 mm wide, open; rachises sparsely pilose to hirsute; branches (5)10-15(18), 2-6 cm long, 0.4-0.6 mm wide, pubescent to setose, not winged, spikelets in unequally pedicellate pairs; pedicels 0.5-1 mm, pubescent, apices glabrous. Spikelets 3.2-3.9 mm long, 1.1-1.3 mm wide, lanceolate to ovate. Lower glumes present as a membranous extension of the calluses; upper glumes equaling the lower lemmas, hairy, lanceolate to ovate, 5-veined, acute, unawned; lower lemmas 3-3.5 mm long, 1.1-1.3 mm wide, lanceolate to ovate, glabrous or sparsely pubescent, 5-veined, acute, unawned; lower paleas fully developed or absent; anthers absent or 3; upper lemmas 2.2-2.6 mm, indurate, elliptic, rounded, mucronate, mucros less than 0.2 mm; upper paleas 2-2.5 mm, indurate. 2n = 36.

Eriochloa polystachya is native to the West Indies, Costa Rica, Honduras, and South America. It was introduced into the United States as a forage crop and is now established at some locations in Florida and Texas.