GRAMINEAE (GRASS FAMILY) 



39 



Shallow plowing or surface cultivation merely stimulates the 

 growth of the grass. 



PORCUPINE-GRASS 



Stlpa spdrtea, Trin. 



Other English names: Weather Grass, Needle Grass, Auger-seed 



Grass. In South Dakota it is called Wild Oats. 

 Native. Perennial. Propagates by seeds. 

 Time of bloom : June to July. 

 Seed-time : July to August. 

 Range: Prairies of the Middle Western States from Ohio to the 



Rocky Mountains, north to Manitoba, British Columbia, and 



the Saskatchewan region. 

 Habitat : Dry soil ; wild meadows 



and pastures. 



A large, stout grass, growing in 

 tufts from a matted cluster of fibrous 

 roots. Culms two to four feet tall, 

 simple, erect, smooth. Sheaths long, 

 mostly overlapping, slightly rough ; 

 basal blades about half as long as 

 the culm, involute, and tapering to 

 a thread-like point ; stem leaves six 

 inches to a foot long, hardly more 

 than a sixth of an inch wide, gener- 

 ally flat but sometimes involute, 

 with long, attenuate points. Pani- 

 cles long and slim, with erect 

 branches, the base at first often 

 enclosed by the sheath but later 

 much exserted. Spikelets one-seeded, 

 the glumes smooth, very narrow 

 and bristle-pointed, exceeding an 

 inch in length; the lemma tightly 

 enfolding the seed, hard, stiff, brown, 

 its lower part clothed with short 

 rigid hairs, and having a sharp- 

 pointed beak or callus, and at the 

 tip an awn, sometimes six inches 

 long, rough, stiff, strongly twisted 



FIG. 15. Porcupine-grass (Stipa 

 spurted). X J. 



