57. Erianthus Michx. Plumegrass 



Perennials, 1-3 m. tall, forming robust clumps; leaves elongate; ligules narrow, 

 usually hippocrepiform; panicle 1-9 dm. long, terminal, often pyramidal to clavate 

 or even slender; spikelets in pairs, one of each pair sessile, one pedicelled, both 

 perfect, usually 4-6 mm. long (not including awn), typically membranous to 

 coriaceous, usually dorsally villous with long hairs; sterile lemma hyaline, shorter, 

 with usually 1 median nerve; fertile lemma narrow, ovate-lanceolate, hyaline, with 

 usually a prominent straight or twisted exserted awn 4-20 mm. long; palea (if 

 present) hyaline. 



A genus of 28 species of southeast Asia to southeast Europe, Madagascar, and 

 the warmer parts of America. 



1. Culm appressed-hairy below the panicle (2) 

 1. Culm glabrous below the panicle (3) 



2(1). Awn straight or slightly flexuous 4. E. giganteus. 



1. Awn loosely twisted 3. E. alopecuroides. 



3(1). Hairs subtending the spikelet few and short or absent; panicle nearly com- 

 pletely glabrous; awn straight 1. E. strictus. 



3. Hairs subtending the spikelet as long as or longer than the spikelet; panicle 

 very hairy; awn 2 cm. long, coiled 2. E. contortiis. 



1. Erianthus strictus Baldw. Narrow plumegrass. 



Perennial; culms 1-2 m. tall, relatively slender, glabrous; nodes sometimes 

 hirsute with stiflf erect deciduous hairs; internode below the panicle glabrous; 

 foliage glabrous; lower sheaths narrow and crowded; blades mostly 4-12 mm. 

 broad; panicle 2-4 dm. (rarely 8 dm.) long, strict (about 1-2 cm. thick), the 

 branches closely appressed; spikelets brown, about 8-1 1 mm. long (not including 

 awn), scabrous, nearly naked to sparsely short-hairy at base; awn straight, 15-20 

 mm. long; rachis joint and pedicel scabrous. 



Rare in moist sandy places, marshes and swamps, in Okla. {Waterfall), e. and 

 s.e. Tex., fall; Va. to Fla. and Tex., n. to Tenn. and Mo. 



2. Erianthus contortus Baldw. Bent-awn plumegrass. 



Perennial; culms 1-2 m. tall, glabrous or sometimes sparsely appressed-pilose 

 below the panicle; nodes glabrous or pubescent with erect deciduous hairs; inter- 

 nodes below the panicle glabrous; sheaths sparsely pilose at summit or glabrous; 

 blades 10-15 mm. broad, scabrous; panicle 15-30 cm. long, narrow, the branches 

 ascending but not closely appressed; spikelets 6-8 mm. (excluding awn) long, 

 brownish, the basal hairs nearly or about as long as the spikelet; awn about 2 cm. 

 long, spirally coiled at base; rachis joint and pedicel villous. 



Rare in moist sandy places, especially wet pinelands, in Okla. {Waterfall), 

 e. and s.e. Tex., fall; Md. to Fla. and Tex., n. to Tenn. and Okla. 



3. Erianthus alopecuroides (L.) Ell. Silver plumegrass. 



Perennial; culms robust, 15-30 dm. tall, appressed-villous below the panicle 

 and usually on the nodes; sheaths pilose at the summit; blades 12-20 mm. wide, 

 scabrous, pilose on upper surface toward base; panicle 2-3 dm. long, silvery to 

 tawny or purplish: spikelets 5-6 mm. long, pale, sparsely villous, shorter than 

 the copious basal hairs; awn 10-15 mm. !ong, flat, loosely twisted; rachis joint 

 and pedicel long-villous. E. divaricatus Hitchc. 



Infrequent in sandy woodlands, usually near water or in seepage, in Okla. 

 {Waterfall), c. and s.e. Tex., fall: N.J. to ill., s. Mo. and Okla., s. to Gulf States. 



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