46 



1. A. Eeqnivalvis, Trin. (Deyeuxia sequivalvis, Benth.) Califor- 



nia to Alaska. 



2. A. arachnoides, Ell. Tennessee to Texas. 



3. A. arenaria, Serib. California. 



4. A. asperifolia, Trin. California. 



5. A. canina, Linn. Monntains of Xew England to Rocky Moun- 



tains. 

 A grass usually of low size, 6 to 12 inches high, with slender 

 culms and a light, flexible, expanded panicle, and with a perplexing 

 variety of forms. There are several varieties growing in mountain- 

 ous regions throughout the United States, and in Europe. It forms 

 a close sod, and affords considerable pasturage in those regions. 

 A. canina, var. alpina, Oakes. New England. 

 A. canina, var. rupestris, Gray. (A. rupestris, Chap.) Mountains 

 North Carolina. 



6. A. elata, Trin. Massachusetts to Texas. 



7. A. exarata, Trin. Wisconsin to Oregon, California, Nevada, 



and Arizona. 

 This is chiefly a northern species, being found in Wisconsin and 

 westward to the Rocky Mountains, also in British America, and 

 California to Alaska. It is very variable in appearance, and pre- 

 sents several varieties. It is generally more slender in growth than 

 the common red top. The panicle is usually longer, narrower, and 

 looser. In all the forms the palet is wanting or is very minute. 

 The form chiefly growing on the Pacific slope from California to 

 Alaska is often more robust than the A. vulgaris, growing 2 to 3 

 feet high, with a stout, firm culm, clothed with three or four broad- 

 ish leaves, 4 to 6 inches long. The panicle is 4 to 6 inches long, 

 pale green, rather loose, but with erect branches. 

 A. exarata, var. littoralis, Yasey. Oregon. 



8. A. exigna, Thurb. California. 



9. A. foliosa, Vasey. California and Oregon. 



10. A. geminata, Trin. Oregon to Alaska. 



11. A. grandis, Trin. California to Alaska. 



12. A. humilis, Yasey. Oregon and Washington Territory. 



13. A. microphylla, Steud. Oregon and California. 



14. A. mucronata, Presl. Oregon and California. 



15. A. multiculmis, Yasey. South California. 



16. A. pallens, Trin. Oregon and California. 



