Eragrostis mexicana |
Eragrostis frankii |
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giant helleborine, Mexican love grass, Orcutt's lovegrass |
sandbar lovegrass, éragrostide de Frank |
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Habit | Plants annual; cespitose, without innovations. | Plants annual; cespitose, without innovations. | ||||
Culms | 10-130 cm, erect, sometimes geniculate, glabrous, sometimes with a ring of glandular depressions below the nodes. |
10-50 cm, erect to geniculate, glabrous, often with glandular pits below the nodes. |
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Sheaths | sometimes with glandular pits, pilose near the apices and on the collars, hairs to 4 mm, papillose-based; ligules 0.2-0.5 mm, ciliate; blades 5-25 cm long, 2-7(9) mm wide, flat, abaxial surfaces glabrous, adaxial surfaces scabridulous, occasionally pubescent near the base. |
mostly glabrous, apices hirsute, hairs to 4 mm, often also with glandular pits; ligules 0.2-0.5 mm, ciliate; blades (2)4-10(21) cm long, 1-4 mm wide, flat to involute, glabrous abaxially, scabridu-lous adaxially. |
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Panicles | (5)10-40 cm long, (2)4-18 cm wide, ovate, rachises angled and channeled; primary branches 3-12(15) cm, solitary to whorled, appressed or diverging to 80° from the rachises; secondary branches somewhat appressed; pulvini glabrous; pedicels 1-6(7) mm, almost appressed to narrowly divergent, stiff. |
4-20 cm long, less than 1/2 the height of the plants, 2-10(14) cm wide, narrowly elliptic, open; primary branches 2-6 cm, compact, diverging 20-70° from the rachises, capillary, sometimes with glandular pits, naked basally; pulvini glabrous; pedicels 1.5-5 mm, divergent. |
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Spikelets | (4)5-10(11) mm long, 0.7-2.4 mm wide, ovate to linear-lanceolate, gray-green to purplish, with 5-11(15) florets; disarticulation acropetal. |
(1.7)2-4(5.6) mm long, 1-2(2.5) mm wide, broadly ovate to lanceolate, plumbeous to reddish-purple, with 3-6 florets; disarticulation acropetal, paleas persistent. |
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Glumes | subequal, 0.7-2(2.3) mm, ovate to lanceolate, membranous; lemmas 1.2-2.4 mm, ovate, membranous, glabrous or with a few hairs, gray-green, lateral veins evident, often greenish, apices acute; paleas 1-2.2 mm, hyaline, keels scabrous, apices obtuse to truncate; anthers 3, 0.2-0.5 mm, purplish. |
narrowly lanceolate to lanceolate, hyaline; lower glumes 1-1.5 mm; upper glumes 1-1.8 mm; lemmas 1.1-1.6 mm, broadly ovate, membranous, lateral veins inconspicuous, apices acute; paleas 1-1.5 mm, hyaline, keels scabridulous, apices obtuse; anthers 2 or 3, 0.2-0.3 mm, purplish. |
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Caryopses | 0.5-0.8(1) mm, ovoid to rectangular-prismatic, laterally compressed, shallowly to deeply grooved on the adaxial surface, striate, reddish-brown, distal 2/3 opaque. |
0.4-0.7 mm, ovoid to rectangular-prismatic, striate, reddish-brown, adaxial surfaces flat or shallowly grooved, distal 2/3 opaque. |
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2n | = 60. |
= 40, 80. |
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Eragrostis mexicana |
Eragrostis frankii |
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Distribution |
AZ; CA; CO; DE; FL; IA; ID; IL; IN; MA; MD; ME; ND; NM; NV; OR; SC; TX; UT; WA; WI; BC; ON
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AL; AR; CT; DC; FL; GA; IA; IL; IN; KS; KY; MA; MD; MI; MN; MO; MS; NC; NE; NH; NJ; NM; NY; OH; OK; PA; SC; TN; TX; VA; VT; WI; WV; NB; ON; QC
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Discussion | Eragrostis mexicana grows along roadsides, near cultivated fields, and in disturbed open areas, at 100-3000 m. It is native to the Americas, its native range extending from the southwestern United States through Mexico, Central and northern South America, to Argentina. Within the Flora region, it has been introduced beyond its native range, often becoming an established part of the flora. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eragrostis frankii is native in the central and eastern United States, but it has been found, as an introduction, in southern Ontario, and appears to be increasingly common in the northeastern United States. It grows in moist meadows, along streams and sand bars, in forest openings, and along roadsides, at 5-1500 m, usually in association with Pinus, Quercus, Acer, and Fagus grandiflora. The record from Santa Fe County, New Mexico, is based on a specimen collected by Fendler in 1847; there are no other collections from the state. Fendler's specimens seem to represent either an accidental introduction that did not become established or a labeling error. Eragrostis frankii is similar to E. capillaris, but differs in its frequent possession of glandular pits, its flat or more shallowly grooved caryopses, shorter pedicels, and glabrous sheath margins, and in having panicles that are usually less than half as long as the culms. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 78. | FNA vol. 25, p. 79. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | E. frankii var. brevipes | |||||
Name authority | (Hornem.) Link | C.A. Mey. ex Steud. | ||||
Web links |
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