GRAMINEAB (GRASS FAMILY) 55 



3. Sporobolus vaginaeflorus (Torr.) Wood, Classbook 775. 1861. Slender 

 caespitose annual, 2-4 dm. high: leaves 2 mm. wide or less, smooth and 

 glabrous beneath, scabrous and hairy near the base above, attenuate into a 

 slender involute point: panicles spike-like, terminal and axillary, about 2 cm. 

 long, mostly inclosed in the somewhat inflated leaf-sheaths: spikelets 3.5-4.5 

 mm. Jong: glumes unequal, acuminate; lemma scabrous, sparingly appressed- 

 pubescent, about as long as the second glume and equaling or slightly ex- 

 ceeded by the very acute palet. — Infrequent; extending into our range from 

 the east. 



4. Sporobolus simplex Scribn. U. S. Dept. Agr. Div. Agros. Bull. 11: 48. 

 1898. Very slender densely tufted annual, 5-30 cm. high, with short narrow 

 leaves, scape-like culms, and hnear, few-flowered panicles 2 cm. long, exserted 

 nearly half their length: spikelets about 1.5-2 mm. long: glumes unequal, 

 1-nerved, obtuse and usually erose-dentate at summit; lemma 3-nerved, 

 acuminate and cuspidate. [S. fiUformis (^Thurb.) Scribn. U. S. Dept. Agr. Div. 

 Agros. BuU. 17: 173. 1899.]— Extending mto our range from the west. 



5. Sporobolus confusus (Fourn.) Vasey, Bull. Torr. Bot. Club 15: 293. 

 1888. Slender branching tufted annual, 8-20 cm. high, with capillary ovoid 

 or oblong panicles 8-15 cm. long: leaves flat, 1-4 cm. long, 1.5 mm. or less 

 wide: spikelets 1.25-1.5 mm. long: glumes obtuse, nearly equal, one half to 

 two thirds as long as the lemma, glabrous or pubescent; lemma obtuse, usually 

 pubescent, sometimes glabrous. — ^Throughout our range. 



6. Sporobolus asperifolius (Nees & Mey.) Thurb. in Wats. Bot. Cal. 2: 269. 

 1880. Slender leafy perennial, 10-35 cm. high, with erect culms from a de- 

 cumbent and branched base and diffuse panicles 6-10 cm. long: leaves numer- 

 ous, 2-8 cm. long, 2-3 mm. wide at base, acuminate, strict, often erect, flat, 

 glabrous, smooth beneath, very rough above: spikelets 1.5 mm. long, occa- 

 sionally 2-3-flowered: glumes subequal, acute, glabrous, sparingly scabrous; 

 lemma obtuse or acute, glabrous, somewhat exceeding the second glume. — 

 Throughout the western half of North America. 



7. Sporobolus airoides Torr. Pac. R. R. Rept. 7^: 21. 1856. Stout coarse 

 and rigid densely caespitpse perennial, 3-9 dm. high, with long, narrow leaves 

 and open spreading pyramidal panicles 10-25 cm. long: leaves smooth be- 

 neath, scabrous above and sometimes sparingly hairy near the base, 1-3 mm. 

 wide at the base, attenuate into a long slender involute point; the basal about 

 one half as long as the culm; the upper culm leaves 5-12 cm. long: spikelets 

 1.5-2 mm. long: glumes acute, glabrous, nerveless, unequal, the first about 

 half as long as the second; lemma equaling the second glume and the palet. — 

 From Mexico to Dakota and west to the Pacific States. 



8. Sporobolus cryptandrus (Torr.) Gray, Man. 576. 1848. Erect glabrous 

 perennial, 4-7 dm. high: sheaths with a dense pilose ring at the summit; 

 leaves 7-15 cm. long, 2-A mm. wide, flat, scabrous above, long-acuminate: 

 panicles 12-20 cm. long, spreading in flower, usually narrow, more or less in- 

 closed in the upper sheath: spikelets 2-2.5 mm. long: glumes acute, glabrous, 

 the first one half as long as the second, which is about as long as the lemma. — 

 Across the continent northward, and south in the interior to Mexico. 



9. Sporobolus argutus (Nees) Kunth, Enum. 1: 215. 1833. Caespitose 

 perennial, 2-4 dm. high, with flat leaves and open panicles 3-8 cm. long, the 

 branches verticillate and spreading in flower: leaves 25-50 mm. long, 2-4 mm. 

 wide at the base, acuminate, smooth and glabrous beneath, scabrous and 

 often sparingly hairy at the base above: spikelets 1.5 mm. long: glumes smooth 

 and glabrous, the first rounded ,or obtuse, one fourth as long as the acute 

 second one; lemma about equaling the second glume, acute. — Colorado and 

 southward. 



10. Sporobolus heterolepis Gray, Man. 576. 1848. Rather stout erect 

 caespitose perennial 3-9 dm. high: leaves involute-setaceous, glabrous, the 

 margins and upper part of the midrib very rough; the basal about three 

 fourths as long as the culm, occasionally equaling it; those of the culm 

 shorter: panicle loose and open, 7-25 cm. long: spikelets 4-5.5 mm. long: 

 gluraes very unequal, sharply acuminate-pointed, the first subulate, about 



