344 



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



about 1 mm. long; palea obsolete. 

 O — Known only from San Diego 

 County, Calif. 



16. Agrostis microphylla Steud. 

 (Fig. 475.) Annual; culms branching 

 at base, slender, erect or ascending, 

 8 to 40 cm. tall, commonly short and 

 tall culms in the same tuft; blades 

 2 to 15 cm. long, rarely longer, 1.5 

 to 3 mm. wide, scabrous; panicle 

 mostly 2 to 8 cm. long (exception- 

 ally less or to 10 cm.), narrow, dense, 

 often lobed; glumes subequal, 3 to 4.4 

 mm. long, acuminate to awn-tipped; 

 lemma 1.7 to 1.9 mm. long, minutely 

 toothed, awned from about the 

 middle, the awn geniculate, 3.5 to 6 

 mm. long, rarely longer; palea want- 

 ing. O — Moist open ground, Van- 

 couver Island, Oregon, California, and 

 Baja California. Variable, occasion- 

 ally small and delicate; glumes 

 rarely only 2 to 2.5 mm. long. A 

 short, densely tufted form with 

 rather thick panicle has been differ- 

 entiated as A. inflata Scribn. The 

 type, from Vancouver Island, is 

 a young plant, the panicles partly 

 included in the slightly inflated upper 

 sheaths. A. microphylla var. major 

 Vasey is a taller form, 40 to 55 cm. 

 tall, the pale panicles to 15 cm. long; 

 glumes 2.5 to 3 mm. long; lemma 1.6 

 to 1.7 mm. long. Only known from 

 Humboldt Mountains, Nev. 



17. Agrostis aristiglumis Swallen. 

 (Fig. 476.) Annual; culms sparingly 

 branching at base, erect, 5 to 15 cm. 

 tall; ligule 2 to 2.5 mm. long, de- 

 current; blades flat, 2 to 15 cm. long, 

 rarely longer, 1.5 to 3 mm. wide; 

 panicle mostly 3 to 6 cm. long, 5 to 

 8 mm. wide, dense; glumes 5 to 6 

 mm. long, attenuate into an awn 1 

 to 2 mm. long, the first glume 1- 

 nerved, the second 3-nerved; lemma 

 3.2 to 3.5 mm. long, relatively firm, 

 scabrous, 5-nerved, awned from the 

 back, the awn geniculate, 6 to 7 mm. 

 long, the lateral nerves excurrent as 

 delicate awns, the inner pair very 

 minute; palea nearly one-third as 

 long as the lemma, nerveless. O 

 — Only known from a "slope of loose 



Figuhe 476. — Agrostis aristigluma. Plant, X Hi 

 glumes and two views of floret, X 5. (Type.) 



longer; panicle spikelike, 2 to 5 cm. 

 long, pale; spikelets short-pediceled; 

 glumes narrow, acuminate, the first 

 3.5 to 4 mm., the second 3 to 3.2 

 mm. long; lemma delicate, about 1.7 

 mm. long, awned from about the 

 middle, the delicate awn about 5 mm. 

 long, geniculate, the lemma loosely 

 pilose except at the 2-toothed sum- 

 mit, the teeth bearing delicate awns 



