608 CLXL GRAMINEiE. Aira. 



25. HOLCUS. 

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

 flowers pedicellate, the lower one perfect and awnless, upper one d" 

 or neuter, awned on the back. 

 H. LANATUs. Soft Grass. 



Hoary pubescent; st. U—2f high; Ivs. lanceolate, 2 — 5' long; s/ieaths 

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

 glumes,; sterile one with a recurved, included awn. — 1\. 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 ; st. simple, erect, 15—20' high ; radical Ivs. as long as the 

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

 spreading, pyramidal, few-flowered, 2 — 3' long; branchlets flexuous; spikelets 

 broad, subcordate, colored, unarmed ; lower palea ciliate. — % Wet meadows, 

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



2. H. ALPiNA. Roem. & Schultz. 



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

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

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

 lanceolate ; lower Ji. with an awn about as long as the paleae. — %. Summits of 

 the White Mts., Bigeloio. Jn. 



27. ANTHOXANTHUM. 



Gr, av^os, 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 ; palese of the $ 2, short, awnless ; 

 stamens 2. 



A. ODORATUM. Svxet-scented Vernal Grass. 



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

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

 lateral fls. 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 early-flowering, deliciously fragrant grass, in most of the States, 

 and Can. May, June. ^ 



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

 flowered. Glumes and paleae 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. 



St. smooth, 1— 2f high, nearly naked; Ivs. setaceous, smooth, with striate 

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

 flexuous branches; ft«.vi.s geniculate, longer than the paleas.— Tj. Vales and hills, 

 U. S. and Brit. Am., common. An r-rect, elegant grass, growing in tufts. Jn. 



