MANTJAL OF THE GRASSES OF THE UNITED STATES 



323 



4. Calamovilfa gigantea (Nutt.) Scribri. and Merr. (Fig. 650.) 

 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. 01 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 

 or usually perennials, with flat or sometimes involute, scabrous 

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



FIGURE 647. Calamovilfa brevipilis. Plant, X 1 A; glumes and floret, X 5. (Brinton. N. J.) 



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

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



