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MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Figure 455. — Calamovilfa brevipilis. Plant, X Yi\ glumes and floret, X 5. (Brinton, N. J.) 



the branches ascending or appressed, 

 sometimes slightly spreading; spike- 

 lets pale, 6 to 7 mm. long; glumes 

 acuminate, the first about 2 mm. 

 shorter than the second; lemma some- 

 what shorter than the second glume, 

 glabrous, the callus hairs copious, 

 more than half as long as the lemma. 

 % — Sand hills and sandy prairies 

 or open woods, Michigan to Alberta, 

 south to Indiana, Colorado, and 

 Idaho. Calamovilfa longifolia var. 

 magna Scribn. and Merr. Panicle 

 more open and spreading. % — 

 Sandy ridges and dunes along Lakes 

 Huron and Michigan. 



4. Calamovilfa gigantea (Nutt.) 

 Scribn. and Merr. (Fig. 457.) Culms 

 robust, mostly solitary, usually 1.5 to 

 2 m. tall, as much as 6 mm. thick at 

 base, with strong creeping rhizomes; 

 sheaths glabrous; blades elongate, 5 

 to 10 mm. wide at base, tapering to a 

 long involute tip; panicle open, as 

 much as 60 cm. long, the branches 

 rather stiffly spreading, as much as 25 

 cm. long; spikelets similar to those of 

 C. longifolia, but somewhat larger; 

 lemma and palea villous along the 

 back; callus hairs copious, half as long 

 as the lemma. % — Sand dunes, 

 Kansas to Utah, Texas, and Arizona. 



70. APERA Adans. 

 (Included in Agrostis L. in Manual, ed. 1) 



Spikelets 1-flowered, disarticulating above the glumes, the rachilla pro- 

 longed back of the palea as a naked bristle; glumes subequal, acuminate; 

 lemma firm, subindurate at maturity, acute, bearing a long delicate straight 

 awn just below the tip; palea nearly as long as the lemma, strongly 2-nerved. 

 Annuals with flat blades and loose or narrow panicles. Type species, Apera 

 spica-venti (L.) Beauv. Name from Greek a, not, and peros, maimed, apparently 

 alluding to the long awn, this nearly wanting in Calamagrostis calamagrostis 

 (L.) Karst. (C. lanceolata Roth), from which Adanson differentiated the genus. 



Panicle open, the branches naked below 1. A. spica-venti. 



Panicle narrow, contracted, interrupted, the branches, or some of them floriferous from 

 the base 2. A. ixterrupta. 



1. Apera spica-venti (L.) Beauv. 

 (Fig. 458.) Annual; culms branched ligule as much as 6 mm. long; blades 

 at base, mostly 40 to 60 cm. tall; flat, 1 to 3 mm. wide; panicle 10 to 



