608 CLXI. GRAMINE^. Aira. 



25. HOLCUS. 

 Spikelets 2-flowered ; glumes herbaceous, boat-shaped, mucronate ; 

 flowers pedicellate, the lower one perfect and awnless, upper one J* 

 or neuter, awned on the back. 



H. LANATL's. Suft Grass. 



Hoary pubescent; st. li — 2f high; lis. lanceolate, 2 — 5' long; sJieaths 

 striate ; panicle oblong, dense, whitish with a purple tinge ; jls. shorter than the 

 glumes,; sterile one with a recurved, included awn. — Tj. Common in wet mea- 

 dows, N. Eng. ! Mid. and W. States. Very soft with whitish down. Jl. 



26. HIEROCHLOA. Gmel. 

 Spikelets 3 -flowered ; glumes 2, scarious ; lateral flowers stami- 

 nate, triandrous ; central flower $ , diandrous (rarely triandrous). 



1. H. BOREALis. Roem. & Schultz. Seneca Grass. 



Smooth, glossy ; 5/. simple, erect, 15 — 20' high ; radical Ivs. as long as the 

 stem, cauline 2 — 4' long, lanceolate, mucronate ; panicle rather 1-sided and 

 spreading, p)Tamidal, few-flowered, 2 — 3' long; branchlds flexuous; spikelets 

 broad, subcordate, colored, unarmed ; loicer paUa ciliate. — %. Wet meadows, 

 Virg. to Arc. Am. Very fragrant. May. 



2. H. ALPlNA. Roem. & Schultz. 



Smooth ; st. erect, stout, 6 — 8' high ; Ivs. linear-lanceolate, acute ; sheaths 

 tumid, longer than the internodes ; panicle ovoid, lA — 2' long, with the branches 

 in pairs ; spikelets purple, compressed, large, longer than the branches ; glvmes 

 lanceolate ; loicer Jl. with an awn about as long as the palese. — 1^ Summits of 

 the White Mts., Bigelow. Jn. 



27. ANTHOX ANTRUM. 



Gr. av^osj a flower, ^av^os, yellow ; from the color of its spikes. 



Spikelets 3-flowered, the central one $ , the 2 lateral ones neuter, 

 each consisting of one bearded palea : glumes 2, unequal, the upper 

 one larger, enclosing the flowers ; paleas of the $ 2, short, awnless ; 

 stamens 2. 



A. ODORATUM. Swcct-sccnted Vernal Grass. 



St. slender, erect, 10—18' high ; Ivs. short, striate, pale green ; panicle 

 spicate, oblong-ovoid; spikelets pubescent, on short peduncles; paJea; of the 

 lateral Jls. linear-oblong, ciliate on the margin, one of them with a bent awn 

 from near the base, the other with a straight awn from the back near the 

 summit. — An earh^-flowering, deliciously fragrant grass, in most of the States, 

 and Can. May, June, ^ 



Tribe 6. AVEXE^. — Inflorescence paniculate. Spikelets solitary, few- 

 flowered. Glumes and palese of similar texture. Upper flowers generally 

 pedicellate, with awn-like processes or abortive rudiments between the upper 

 and the lower ones. Upper palea wtth two keels. 



28. AlRA. 

 Gr. aipa, a deadly weapon ; originally applied to a poisonous plant. 



Spikelets 2-flowered, without abortive rudiments; glumes 2, 

 membranaceous and shining, subequal ; one of the flowers pedicel- 

 late ; paleae subequal, pilose at base, the lower one lacerate at apex 

 and awned on the back. 



1. A FLEXUOSA. 



5*/. smooth, 1— 2f high, nearly naked; Ivs. setaceous, .smooth, with striate 

 sheaths and truncate stipules ; panicle loose, spreading, trichotomous, with long, 

 flexuous branches ; awns geniculate, longer than the paleoe. — % Vales and hills, 

 U. S. and Brit. Am., common. An erect, elegant grass, growing in tufts. Jn. 



