MANUAL OF THE GRASSES OF THE UNITED STATES 



415 



shining, the margins enclosing the lemma as in Panicum. Moderately 

 tall grasses with flat blades and open panicles. Type species, Milium 

 effusum. Milium, old Latin name for millet. 



1. Milium effusum L. (Fig. 861.) Smooth perennial, somewhat 

 succulent; culms slender, erect from a bent base, 1 to 1.5 m tall; 

 blades mostly 10 to 20 cm long, flat, lax, 8 to 15 mm wide; panicle 10 to 

 20 cm long, the slender branches in remote spreading or drooping 

 pairs or fascicles, naked below; spikelets pale, 3 to 3.5 mm long; 

 glumes scaberulous. 21 — Damp or rocky woods, Quebec and 



Nova Scotia to Minnesota, south to Maryland and Illinois (fig. 862); 

 Eurasia. 



82. ORYZOPSIS Michx. Ricegrass 



Spikelets 1-flowered, disarticulating above the glumes; glumes 

 about equal, obtuse to acuminate; lemma indurate, usually about as 

 long as the glumes, broad, oval or oblong, nearly 

 terete, usually pubescent, with a short, blunt, 

 oblique callus, and a short deciduous, some- 

 times bent and twisted awn; palea enclosed by 

 the edges of the lemma. Mostly slender peren- 

 nials, with flat or often involute blades and 

 terminal narrow or open panicles. Type 

 species, Oryzopsis asperijolia. Name from 

 oruza, rice, and opsis, appearance, alluding to 

 a fancied resemblance to rice. 



Nearly all the species are highly palatable to stock, but are usually 

 not in sufficient abundance to be of importance, except 0. hymenoides 

 (Indian ricegrass), which is common in the arid and semiarid regions 

 of the West and furnishes much feed. The seed has been used for 

 food by the Indians. Locally important may be 0. micrantha in the 



Figure 862.— Distribution of 

 Milium effusum. 



Black Hills region and 0. kingii in the high Sierras, 

 sometimes cultivated for forage in California. 



Lemma smooth (rarely pubescent in 0. micrantha) . 

 Blades flat, 5 mm wide or more. Spikelets numerous, 



0. miliacea is 



about 3 mm long. 



1. O. MILIACEA. 



Blades more or less involute, less than 2 mm wide. 



Panicle branches spreading or reflexed; fruit about 2 mm long, pale. 



2. O. MICRANTHA. 



Panicle branches ascending or appressed; fruit about 4 mm long, dark brown. 



3. O. HENDERSONI. 



Lemma pubescent. 



Pubescence on lemma long and silky. 



Panicle-branches and the capillary pedicels divaricately spreading. 



12. O. HYMENOIDES. 



Panicle-branches and pedicels erect or ascending. 



Awn 6 mm long; culms usually not more than 30 cm tall. 



11. 



Awn 12 mm long; culms 30 to 60 cm tall 10. 



Pubescence on lemma short, appressed. 



Spikelets, excluding awn, 6 to 9 mm long; blades flat. 



Basal blades elongate, uppermost not more than 1 cm long. 



8. O 



Basal blades reduced, upper elongate 9. 



Spikelets, excluding awn, 5 mm long or less; blades involute or subinvolute. 

 Panicle branches erect or appressed. 



Blades and panicle stiff, erect; awns about 5 mm long_ 4. O. exigua. 

 Blades flexuous, the panicle somewhat so; awns at least 10 mm long. 



7. O. kingii. 

 Panicle branches loosely ascending or spreading. 



Awn not more than 2 mm long, straight or nearly so. 5. O. pungens. 

 Awn 10 to 20 mm long, weakly twice-geniculate._ 6. O. canadensis. 

 55974°— 35 27 



O. WEBBERI. 

 O. BLOOMERI. 



ASPERIFOLIA. 

 O. RACEMOSA. 



