CACTACEAE. 239 



Filament red ; fruit very prickly. 6. O, rhodantha. 



Filaments yellow ; fruit scarcely prickly. 7. O. xanthostemma. 



Internodes oblong or nearly cylindrical, turgid and nearly terete, easily break- 

 ing off, 2-4 cm. long. 8. O. fragilis. 

 Internodes of stem elongated, cylindric or prismatic. 



Tubercles of the stem sharp and comb-like ; erect shrub. 9. O. arborescens. 



Tubercles neither prominent nor comb-like ; plant decumbent. 



10. O. Davisii. 



1. Opuntia mesacantha Raf. (O. Rafinesqui Engelm.) On plains and 

 prairies especially in sandy soil from Wise, and Minn, to Ky. and Ariz. Alt. 

 4000-5500 ft. Fort Collins; Denver; Boulder. 



2. Opuntia camanchica Engelm. On plains from Colo, to Tex. and Ariz. 

 Alt. np to 6000 ft. Colorado Springs. 



3. Opuntia Schweriniana K. Sch. In dry places in Colo. Sapinero. 



4. Opuntia tortispina Engelm. On plains from Neb. and Colo, to Ind. Terr. 

 Exact locality not given. 



5. Opuntia polyacantha Haw. (O. missouriensis DC.) On plains and 

 hills from N. D. and B. C. to Ind. Terr., N. M. and Ore. Alt. 4000-7000 ft. 

 Quimby; Ft. Collins; Denver; Walsenburg; North Cheyenne Canon. 



6. Opuntia rhodantha K. Sch. On plains of Neb. and Colo. Alt. 4000-8000 

 ft. " Colorado " ; Grand Junction ; Boulder. 



7. Opuntia xanthostemma K. Sch. On plains of western Colo. Mesa 

 Grande. 



8. Opuntia fragilis Haw. On prairies and plains from Wise, and B. C. 

 to Kans. and Colo. Denver ; Boulder. 



9. Opuntia arborescens Engelm. On plains and hills from Colo, to Tex. 

 and Ariz. Alt. 4000-6000 ft. Pueblo; Piedra. 



10. Opuntia Davisii Engelm. In dry soil from Colo, to Tex. and Calif. 

 La Plata Valley, Mancos and McElmo (Brandegee), 



Order 36. THYMELIALES. 



Family 94. ELAEAGNACEAE Lindl. OLEASTER FAMILY. 

 i. LEPARGYRAEA Raf. BUFFALO-BERRY. 



Leaves ovate or oval, green above; shrub thornless. i. L. canadensis. 



Leaves oblong, silvery on both sides ; shrub thorny. 2. L. argentea. 



1. Lepargyraea canadensis (L.) Greene. (Shepherdia canadensis L.) In 

 woods from Newf. and Alaska to N. Y., Colo, and Ore. Alt. 6500-12,000 ft. 

 Villa Grove, Black Canon; Georgetown; Bear Creek Divide, West La 

 Plata Mountains; southeast of Ouray; Box Canon, west of Ouray; Cham- 

 bers' Lake ; Graham's Park ; mountains of Larimer Co. ; Stove Prairie Hill ; 

 Bosworth's ranch ; Eldora to Baltimore. 



2. Lepargyraea argentea (Nutt.) Greene. (Shepherdia argentea Nutt.) 

 On sandy river banks and islands from Man., Sask. and Alb. to Kans., N. M. 

 and Nev. Alt. 4000-7000 ft. Grand Junction; Cimarron ; Mancos; La 

 Porte, Larimer Co. ; Wolcott ; Hotchkiss ; Dolores ; Durango. 



