GRASS FAMILY 



169 



37. SPHENOPHOLIS Scribn. RhodoraS: 142. 1906. 



Spikelets 2- or 3-flo\vered, the pedicel disarticulating below the glumes, the rachilla 

 produced beyond the upper tloret ; glumes unlike in shape, the first narrow, acute, 1-nerved. 

 the second broadly obovate. 3-5-nerved, somewhat coriaceous; lemmas firm, scarcely nerved, 

 awnless, the first a little shorter or a little longer than the second glume. Perennials with 

 usually flat blades and narrow panicles. [Greek, wedge-scale.] 



Species 4, United States, extending into Mexico and the West Indies. Type species, Aira obtusaia 

 Michx. 



Panicle dense, erect, somewhat lobate; second glume obovate. 1- •?• ohtu.sata luhala. 



Panicle lax, usually nodding; second glume oblanceolate. i- •>• pollens. 



1. Sphenopholis obtusata lobata (Trin.) Scribn. 

 Early Bunch-grass, Prairie-grass. 



Fig. 3S2. 



Trisetum lobatum Trin. Mem. Acad. St. Petersb. VI. Math. Phys. 



Nat. 1: 66. 1830. 

 Sphenopholis obtusata lobata Scribn. Rhodora 8: 144. 1906. 



Culms erect, 30-60 cm. tall ; sheaths and blades sca- 

 brous : panicle narrow and compact, often spikelike, 

 more or less interrupted or lobed, especially near base, 

 5-10 cm. long ; glumes subequal, the second subcucuUate, 

 the broad chartaceous margins smooth and shining. 



Prairies and open woods throughout the United Statrs. 

 Frequent in Washington and Oregon in the Upper Sonoran 

 Zone; rare in California. Apr. -July. Type locality: North 

 America. 



2. Sphenopholis pallens fSpreng.) 

 Scribn. 



Shining Prairie-grass. Fig. 383. 



Aira pallens Spreng. Mant. Fl. Hal. 33. 1807. 



Eatonia pallens Scribn. & Merr. U. S. Dept. Agr. Div. 



Agrost. Circ. 27: 7. 1900. 

 Sphenopholis pallens Scribn. Rhodora 8: 145. 1906. 



Culms 30-100 cm. tall, usually slender; sheaths 

 glabrous ; blades 5-20 cm. long. 4-6 mm. wide, 

 scabrous on the nerves ; panicle lax, nodding, 8-20 

 cm. long; spikelets 3-4 mm. long, oblong-lanceo- 

 late ; glumes unequal, scabrous on the keels, the 

 first linear, the second broadly oblanceolate. 



}iIoist op^n ground, in the Arid Transition Zone; 

 eastern Washington and eastward to New England. June- 

 July. Type locality: Pennsylvania. 



38. KOELERIA Pers. Syn. PI. 1 : 97. 1805. 



Spikelets 2-4-flowered, the rachilla disarticulating above the glumes 

 bevond the perfect florets, sometimes bearing a reduced or sterile floret at 

 usually about equal in length but unequal in shape, the lower narrow 

 shorter, 1-nerved, the upper somewhat broader above the middle, wider 

 3-5-nerved: lemmas somewhat scarious and shining, the lowermost a little 

 glume, obscurelv 5-nerved, acute or short-awned. Annual or perennial 

 moderately tall grasses with narrow blades and spikelikc panicles. [Name 

 G. L. Koeler, an early writer on grasses.] 



Species about 20 in the temperate regions of both hemispheres. Type species, Aira 



Plants annual; culms glabrous below panicle. 1 



Plants perennial: culm puberulent below panicle. 



and prolonged 

 the tip ; glumes 

 and sometimes 



than the lower, 

 longer than the 

 slender low or 



d for Professor 



cristata L. 



. K. phleoides. 

 K. cristata. 



