MANTUAL OF THE GRASSES OF THE UNITED STATES 



323 



4. Calamovilfa gigantea (Nutt.) Scribn. 

 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. longi- 

 folia, but somewhat larger; lemma 

 and palea villous along the back; 

 callus hairs copious, half as long as 

 the lemma. % — Sand dunes, North 

 Dakota to Texas and west to Arizona 

 (fig. 651). 



64. AGROSTIS L. Bentgrass 



Spikelets 1 -flowered, disarticulat- 

 ing above the glumes, the rachilla 

 usually not prolonged; glumes equal 

 or nearly so, acute, acuminate, or 

 sometimes awn-pointed, usually sca- 

 brous on the keel and sometimes on the 

 back; lemma obtuse, usually shorter 

 and thinner than the glumes, awnless 

 or dorsally awned, often hairy on the 

 callus; palea usually shorter than the 

 lemma, 2-nerved in only a few species, 

 usually small and nerveless or obsolete. 

 Delicate to moderately tall annuals 

 usually perennials, with flat 



and Merr. (Fig. 650.) 



Figure 646.— Calamovilfa curtissii. Plant, X 

 Yi, glumes and floret, X 5. (Garber, Fla.) 



or 



or sometimes involute, scabrous 

 blades, and open to contracted panicles of small spikelets. Type 



Figure 647.— Calamovilfa brevipilis 



(Brinton. X. J.) 



species, Agrostis stolonifera. Name from Greek agrostis, a kind of 

 grass, from agros, a field; the word agrostology is from the same root. 



