128 



GRAMINEAE (GRASS FAMILY) 



Var. palustris Scribn. Similar to the species ; culms reclining or ascending, 

 very slender or almost filiform ; leaves 2-4 cm. long, 2-3 mm. wide ; panicles 

 5-10 cm. long, very slender, more loosely flowered; spikelets (excluding the 

 awn) 2.5 mm. long, usually purple; glumes acute, unequal, 

 the first about , the second about % the length of the bidentate 

 owned lemma; awn flexuous, 4-6 mm. long. (M. palustris 

 Scribn.) Swampy ground, D. C. and 111. Sept., Oct. 



2. TRICHOCHLOA (Beauv.) Trin. Panicle very loose and 

 open, the long branches and pedicels capillary ; leaves narrow, 

 often convolute-bristle-form. 



8. M. capillaris (Lam.) Trin. (HAIR GRASS.) Caespitose, 

 erect, with simple rigid culms, 6-10 dm. high ; sheaths overlap- 

 ping; blades 1-3 dm. long, involute, rigid; panicle about \ the 

 entire height of the plant, its spreading capillary branches loosely 

 flowered; spikelets purple, 4 mm. long (excluding the awn) ; 

 glumes subequal, acute, or the second aristate-pointed, about \ as 

 long as the lemma which bears a delicate awn 5-20 mm. long. 

 91. M. capillaris. Dry sandy or gravelly soil, Mass, to Fla., west to Mo. and Tex. 

 *pikeletx8. FIG. 91. 



27. BRACHYELYTRUM Beauv. 



Spikelets 1-flowered, in a few-flowered narrow panicle ; glumes minute, 

 unequal ; floret with a short callus, the rhachilla prolonged 

 behind the palea into a slender naked bristle ; lemma firm, 

 narrow, 5-nerved, terminating in a long straight awn ; palea 

 firm, nearly as long as the lemma ; grain oblong, inclosed in 

 the lemma and palea. Perennials, with simple culms from 

 short knotty rootstocks. (Name composed of /3paxfo, short, 

 and <t\vrpov, husk, from the minute glumes.) 



1. B. er^ctum (Schreb.) Beauv. Culms erect, 6-10 dm. 

 high ; sheaths sparsely retrorse-hispid ; blades 8-15 cm. long, 

 1-1.8 mm. wide, lanceolate, very scabrous, pilose on the 

 nerves beneath ; panicle narrow, 1-2 dm. long ; spikelets 1 cm. 

 long (excluding the awns), on capillary pedicels; first glume 

 often obsolete, second sometimes aristate ; floret scabrous. 

 (B. aristatum Beauv.) Rocky woods, Nfd. to Minn., and 92. B. erectum. 

 south W. July, Aug. FIG. 92. Spikelete x 1ft. 



93. II. schoenoides. 

 Inflorescence x ft. 

 Spikelets x 8. 



28. HELE6CHLOA Host 



Spikelets 1-flowered, flattened, in dense oblong-ovoid spike- 

 like panicles ; glumes awnless, shorter than the 1-nerved lemma 

 which subtends a palea of nearly equal length. Low caespi- 

 tose branching annuals, the numerous spike-like panicles 

 partly included in the inflated sheaths. (Name from ?Xos, 

 a meadow, and x^ a i grass.) 



1. H. SCHOENOIDES (L.) Host. Usually almost prostrate; 

 leaves rather rigid, tapering to a sharp point ; spike 1.5-4 cm. 

 long. Waste places, N. Y. to Del. and e. Pa. ; also Chicago, 

 111. (Bebb). (Adv. from Eu.) FIG. 93. 



29. PHLEUM L. 



Spikelets 1-flowered, flattened, in dense cylindrical spike-like panicles; 

 glumes equal, ciliate on the keels, and abruptly awn-pointed, longer than the 



