•«RAMINE£. 



433 MUHLENBERGIA. 



6. POLYPO'GON. 



Inflorescence contracted into a spike; glumes 2, nearly 

 equal, obtuse, with long awns ; paleai shorter than the glumes, 

 lower one entire, with a short, straight, tender awn (some- 

 times awnless), upper one bifid, toothed. 



P. glomera'tus. Willd. i ■ u 



Stem compressed, erect, smooth, with appressed branches, 3—4 feet liigh ; 

 leaves somewhat 2-ro wed, erect, flat, rough, 3— 5 inches long, with closed 

 sheaths ; panicle dense, conglomerated, interrupted, 2—3 inches long, many- 

 flowered ; glumes linear,^ the length of their awns; loioer palea mucronate. 

 Bog meadows. Aug. Sept. 



7. TRrCHO'DIUM. 



Inflorescence a capillary panicle; glumes 2, subequal, nar- 

 row and acute; palea 1, awnless, shorter than the glumes, 

 ioosely enclosing the caryopsis. 



1. T. laxifi.o'rum. Mx. Vanity or Hair Grass. 



Stem erect, smooth, very slender, 1 — 2 feet high ; leares 3 — 6 inches long, 

 linear-lanceolate, scabrous, lower ones involute, upper ones siiorter and flat ; 

 sheath rather open ; panicle difFiise, with long, capillary, verlicillate branches 

 ■trichotomously divided near the end; spikelets in terminal clusters, purple ; 

 glumes linear-lanceolate. Pastures and roadsides, forming a dense turf. Jn. 



2. T. scABRUM. Muh. Rough Hair Grass. 



Stem, geniculate at base, assurgent, branched, 1 — 2 feet high ; leaves rough, 

 striate, linear-lanceolate, 4 — G inches long, with the sheaths commonly closed 

 and smooth ; panicle long, with vcrticillale, divaricate, dichotoinously divided 

 branches which are much shorter than in T. lazijlurum. Spikelets pale green, 

 2iot clustered. Common in dry soils. July. 



8 . M U H L E N B E' R G I A . 

 Panicle nearly sim[)le ; glumes 2, very minute, unequal, 

 fringed ; paleae many times longer than the glumes, linear- 

 lanceolate, nerved, hairy at base; the lower one terminating 

 in a long awn. 



Named in honor of the late Henry Muhlenberg, D. D., no less distinguished 

 as a botanist than as a philanthropist. 



1. M. DiFi'u'sA. Dorp-seed Grass. 



Stem decumbent, dift'use, branching, slender, compressed ; Iranches assur- 

 Tent; leaves 2 — 3 inches long, 2 lines wide, linear-lanceolate, rough, with 

 smooth, striate, open sheaths ; panicles terminal and lateral, with remote, 

 appressed, rough branches ; 5/«7£e/<;/i pedicellate, often purple ; aw/i about as 

 long as the palea. Borders of woods and fields. Aug. 



2. M. ere'cta. Schrcb. 



Stem erect, simple, retrorsely pubescent at the nodes, 2 — 3 feet high; leaves 

 lanceolate, scabrous, ciliate on the margin, 4—6 inches long, 3 or more lines 

 wide, with somewhat open sheaths ; panicle terminal, simple racemose, con- 

 tracted ; spikelets pedicellate, large ; glumes very unequal, upper one subulate ; 

 loicer palea half as long as its awn, upper palea with a short awn ai base 

 lodged in the dorsal groove. Rocky hills. July. 

 MM 



