416 MISC. PUBLICATION 200, IT. S. DEPT. OF AGRICULTURE 



1. Oryzopsis miliacea (L.) Benth. and Hook. (Fig. 863.) Culms 

 relatively stout, sometimes branching, erect from a decumbent base, 

 60 to 150 cm tall; ligule about 2 mm long; blades flat, 8 to 10 mm wide; 

 panicle 15 to 30 cm long, loose, the branches spreading with numerous 

 short-pediceled spikelets beyond the middle ; glumes acuminate, 3 mm 

 long; lemma smooth, 2 mm long, the straight awn about 4 mm long. 

 % — Introduced in a few localities in California; ballast, Camden, 

 N.J., and Philadelphia, Pa.; Mediterranean region. 



2. Oryzopsis micralitha (Trin. and Rupr.) Thurb. Littleseed 

 ricegrass. (Fig. 864.) Culms densely tufted, erect, slender, 30 to 



70 cm tall; ligule 

 about 1 mm long; 

 blades slender, sca- 

 brous, flat or involute, 

 0.5 to 2 mm wide; pan- 

 icle open, 10 to 15 cm 

 long, the branches dis- 

 tant, single or in pans, 

 spreading or finally 

 reflexed, 2 to 5 cm long, 

 with short-pediceled 

 appressed spikelets 

 toward the ends; 

 glumes thin, acumi- 

 nate, 3 to 4 mm long; 

 lemma elliptic, gla- 

 brous, or rarely ap- 

 pressed-pilose, 2 to 2.5 

 mm long, yellow or 

 brown, the straight 

 awn 5 to 10 mm long. 

 % — Open dry woods 

 and rocky slopes, me- 

 dium altitudes, Saskatchewan to Montana, south to New Mexico and 

 Arizona (fig. 865). The form with pilose lemmas is found from 

 Colorado to Arizona. 



3. Oryzopsis hendersoni Vasey. (Fig. 866.) Culms densely 

 tufted, scabrous, 10 to 40 cm tall; leaves mostly basal, the sheaths 



broad, papery, glabrescent; ligule very 

 short; blades subfiliform, involute, scabrous, 

 firm, mostly less than 10 cm long, the one or 

 two culm blades 4 to 5 cm long; panicle few- 

 flowered, 5 to 12 cm long, the few scabrous 

 branches appressed or ascending, spikelet- 

 bearing toward the ends, the lower as much as 

 8 cm long; spikelets short-pediceled; glumes 

 abruptly acute, 5 to 6 mm long; lemma nearly 

 as long as the glumes, glabrous, dark brown at maturity, the awn early 

 deciduous, nearly straight, 6 to 10 mm long. % — Dry or gravelly 

 soil.^ Known only from Mount Clements, Wash. , and from the Ochoco 

 National Forest, Oreg. 



4. Oryzopsis exigua Thurb. Little ricegrass. (Fig. 867.) 

 Culms densely tufted, stiffly erect, scabrous, 15 to 30 cm tall; sheaths 

 smooth or somewhat scabrous; ligule 2 to 3 mm long; blades involute- 

 filiform, stiffly erect, scabrous, 5 to 10 cm long, the culm blades about 



Figure 863.— Ory- 

 zopsis miliacea, 

 X 5. (Kralik, 

 Europe.) 



Figure 864 



Oryzopsis mkrantha. Panicle, X 1; 

 floret X 5. (Hitchcock 22993, N. Mex.) 



Figure 865.— Distribution of 

 Oryzopsis mkrantha. 



