Tkichodium. CLXl. GRAMLNEiE. 599 



6. SPOROBOLUS. Brown. 



Gr. cvopa, a seed ; PaWca, to cast forth ; its fruit ig loose, aiid easily falls out. 



Panicles contracted ; glumes 2, glabrous, awnless, unequal, one or 

 both much shorter than the paleao ; paleaj 2, concave, nearly equal, 

 beardless ; fruit loose, free, not enclosed in the palese. 



S. ASPER. Sullivanf? 



HI. long, white, fibrous ; sL stout, glabrous, geniculate at base, 2f high ; 

 Ivs. rigid, glabrous, 2—8' by 1—3", tapering to a iong, pungent point ; branches 

 with short leaves, barren, also ending in a long, pungent point ; slicaths ciliate at 

 edge and bearing dense tufts of long, white hairs at top ; panicles small, terminal 

 and lateral, half enclosed in the long sheaths; spikekis blackish-green; lower 

 ghiTiie very short, upper nearly as long as the paleae ; fr. compressed, obovate, 

 h" in length,— 71- Ohio, Sidllvant! 



7. POLYPOGON. Desf: 



Gr. TToKvi, many, Jruycuc, beard ; a characteristic term. 



Inflorescence contracted into a spike ; glumes 2, nearly equal, 

 obtuse, with long awns ; paleae shorter than the glumes, lower one 

 entire, with a short, straight, tender awn (sometimes awnless), upper 

 one bifid, toothed. 



P. RACEMosus. Nutt. (P. glomcratus. Willd. Agro.stis racemosus. Mx. 



Muhlenbergia glomerata. Trin.) — Glaucous; st. compressed, erect, smooth, 

 with appressed branches or subsimple, IJ — 4f high ; Ivs. somewhat 2- rowed, erect, 

 flat, rough, 3 — 5' long, with closed sheaths ; panicle spicate, dense, conglome- 

 rated, interrupted, 2 — 3' long, many-flowered ; gluvies linear, f the length of 

 their awns ; lower palece mucronate. — n\. Bog meadows, also on rocky mountains 

 N. Eng. to Mo. ! Aug., Sept. 



8. TRICHODIUM. 



Gt. 9pt^, rpiKog, hair; from its capillary inflorescence. 



Inflorescence a capillary panicle ; glumes 2, subequal, narrow and 

 acute ; palea 1 (or 2, the upper very minute), awnless, shorter than 

 the glumes, loosely enclosing the caryopsis. 



1. T. LAxiPLORUM. Michx. (Agrostis Michauxii. Trin.) Thin grass. 



SL erect, smooth, very slender, I— 2f high; Ivs. 3—6' long, linear-lanceo- 

 late, scabrous, lower ones involute, upper ones shorter and flat ; sheath rather 

 open; panicle large and very diffuse, with long, capillary, verticillate branches, 

 trichotomously divided near the end ; spikekis in terminal clusters, purple ; glumes 

 linear-lanceolate. — % Pastures and roadsides, U. S. and Brit. Am. Jn. 



2. T. MONTANUM. TorT. (Agrostis Torreyi. Tuckvi.) Mo%mfain Hair Grass. 

 Sis. caespitose, erect, filiform, simple, in small tufts, 8 — 12' high ; radical 



Ivs. 2 — 3' long, involute-filiform, cauline rather longer ; stip. bifid, serrate ; pan. 

 ovale, branches spreading, finally divaricate, capillary, hispid; spikekis fascieit- 

 late at the ends of the branches ; glumes equal ; palecc with a short, twisted awn 

 at the back. — 7^ Mts. and rocky woods, N. H. and N. Y. 



3. T. scAERUM. Muhl. (Agrostis scabra. Willd.) Rovgh Hair Grass. 



St. geniculate at base, assurgent, branched, 1 — 2f high ; Ivs. rough, striate, 

 linear-lanceolate, 4 — G' long, with the sheaths commonly closed and smooth, 

 panick long, with verticillate, divaricate, dichotomoitsly divided branches which 

 a.-e much shorter than in T. laxiflnrvm ; spikdets pale green, not clustered. — %. 

 Common in dry soils, N. Eng. to 111. July. 



4. T. ALTissiMUM. Miehx. (T. elatum. Ph. Cornucopice alt. Walt.) 



St. erect, rigid, simple, slender, 3f high, leafy ; Irs. broadly linear, sca- 

 brous flat, 6 — 8' long; sheaths scarcely smooth; panicle purple, exserted. con- 

 tracted, branches in whorls of 4s — 6s, erect, rather rigid, and dense-flowered at 

 the ends; glumes subequal, lanceolate, acuminate, scabrous on the keel, about J" 

 51 



