ORDER CXLII. GRAMINACE^}. 595 



4. E. contor'tus, (Ell.) Stem erect, bearded at the joints. Leaves 

 long, linear-lanceolate. Panicle appressed; involucre as long as the 

 glumes; interior palea shortest, with a spirally contorted awn. — If. 

 Sept. — Oct. Low country. 4 — 5 feet. 



Genus XLIIL— ANDROPO'GON. L. (Broom-grass.) 

 (From aner, man, and poaon, beard; from the appearance of the rachis ) 



Flowers polygamous, spiked. Spikelets in pairs, 1 — 2-flow- 

 ered ; the lower ones sterile ; or when but one, it is perfect. 

 Glumes and palese sometimes wanting; when present, the 

 glumes coriaceous. Palece membranaceous, with the lower one 

 generally awned. 



1. A. scopa'rtus, (Mich.) Stem glabrous, tinged with purple. Leaves 

 channeled, slightly hairy; sheaths hairy. Flowers in straight panieles, 

 by pairs on the spikes; the perfect ones sessile, the neuter one stiped 

 and awned. Rachis hairy. Glumes 2, the exterior 5-nerved. Palece 

 purple, with hairy margins, the interior awned at the summit. — 2f. 

 Sept. — Oct. Poor soils. Common. 2 — 3 feet. 



2. A. furca'tus, (Muhl.) Stem erect, glabrous. Leaves linear, nearly 

 glabrous; spikes generally by fours, terminal ; sterile florets without 

 awns, the awn of the perfect floret contorted. — If. August — Sept. 

 Mountains. 2 — 3 feet. 



5. A. macru'rus, (Mich.) Stem erect, slightly compressed. Leaves 

 linear, slightly scabrous ; sheath villous along the margin. Panicles 

 clustered ; spikes conjugate, clustered, each having a sheath. Pedun- 

 cles hairy. Flowers monandrous, with a straight awn. — 2f . October 

 Damp soils. 2 — 3 feet. 



4. A. dissitiflo'rus, (Mich.) Stem erect, branching. Leaves linear, 

 scabrous, with the throat of the sheath hairy. Panicle appressed; 

 spikes conjugate. Flowers by pairs, hairy, monandrous, with a straight 

 awn. — If. Sept. — Oct. Common. 3 — 4 feet. Broom- grass. 



5. A. vagina'tus, (Ell.) Stem erect, glabrous. Leaves long, linear, 

 with glabrous sheaths. Panicle slender, appressed, branches divided; 

 spikes short, solitaiy, or conjugate. Rachis hairy. Gltcmes serrulate. 

 Flowers monandrous. — 2f. Sept. — Oct. Damp soils. 3 feet. 



G. A. terna'rius, (Mich.) Branches remote, solitary, simple, alter- 

 nate, 3-spiked; spikes conjugate. Hairs of the bracts shorter than the 

 glume. Stamens 3. The inner palea 2-cleft, producing from the cleft 

 a long contorted awn. — Mountains. 



7 A. argen'teus, (Cass.) Stem glabrous, branching, tinged with pur- 

 ple. Leaves linear, scabrous. Panicle long, slender ; spikes conjugate, 

 covered with white silvery hairs. Glumes hairy along the margins. — 

 If. Sept.— Oct. Dry soils. 2—3 feet. 



8. A. avena'ceus, (Mich.) (A. ciliatus, Ell.) Stem, erect, sometimes 

 decumbent, pubescent at the joints. Leaves scabrous, slightly hairy. 

 Panicle naked, expanding. Flowers perfect and sterile. Glumes hairy ; 

 the exterior one many-nerved, the iuterior 5-nerved. Palea? ciliate, the 

 interior one awned. — If Sept. Pine-barrens. 3 — 4 feet. 



9. A. nu'tans, (L.) Stem erect, glabrous, lower joints swollen. Leaves 



