200 TRANS. OF THE ACAD. OF SCIENCE. 



ssepe globoso-obovatis vix tuberculatis ; areolis subapproxi- 

 niaiis; foliis minutis subulatis divaricatis ; setis brevissimis, 

 aculeis nullis sou parvulis sen rarius singulo longiore recto ro- 

 busto albido ; floribus sulphureis ; sepalis exterioribus trans- 

 versis obcordatis cuspidatis ; petalis 8 late obovatis emargi- 

 natis; stigmatibus 8 brevibus erectis ; bacca obovata areolis 

 sub-25 stipata ; seminibus irregulariter compressis anguste 

 marginatis. 



In the Pass, west of Steptoe Valley, in the Utah basin ; in 

 flower and fruit at the end of July. Joints 2-3 inches long, 

 and of nearly the same diameter; areola? 6-8 lines apart; 

 leaves smaller than in any other of our species, except 0. ba- 

 silaris, scarcely 1 line long; bristles few on young, none on 

 old joints, about \ 1. long; stouter spines, when present, 3-1 

 inch long. Flowers 3 inches in diameter, pale or sulphur- 

 yellow ; fruit 1 inch long, half as thick, with a very deep um- 

 bilicus and with a few bristles, or here and there a minute 

 spine on the areolae — in the specimens before me apparently 

 fleshy, but perhaps dry at full maturity; seeds very irregular, 

 2 1. or in the longest diameter 2g 1. wide. Loth to increase 

 the number of illy defined species, I provisionally attach this 

 to the New Mexican 0. sphcerocarpa, of which, however, 

 leaves and flowers are as yet unknown, and the fruit is rather 

 different. 



8. Opuntia iivstericixa, fine/. & Big., is evidently a west- 

 ern representative, or may be a western form, of 0. Missou- 

 riensis. (See Bot., Ives' Exp., p. 14.) It was collected in 

 the present Territory of Nevada, between Walker and Carson 

 Rivers. Flowers 2g-3 inches wide, largeii than in Dr. New- 

 berry's specimen ; stigmas 8-10, short, erect. 



0. Opuntia Missouriexsis, DeC, itself is not rare in the 

 deserts between Salt Lake Valley and Rush Valley. Var. 

 albispina, approaching to var. trickbph&ra, was found on 

 Smith Creek, Lookout Mountains; flower 3-3£ inches in di- 

 ameter; ovary with 20 or -!."» scarcely spiny areolae; 5 very 

 short erect stigmas. 



10. Opuntia fbagilis, Haw. Suppl r p.82; Cactus fra gi- 

 lts, Nutt., gen. I, p. 296. Fort Kearney to the North Flatte 

 count iv, in flower in June and July. This, I believe, is the 

 first time, since Nuttall's discovery in 1813, that the flowers 

 of this species were collected. Travellers report the plant 

 very common on the sterile prairies at the foot of the Rocky 

 Mountains, but rarely found in flower, and still more rarely 

 in fruit; it seems to propagate principally by the extremely 

 brittle joints, which even the wind is apt to break off and 

 carry about. I have had for many years specimens in culti- 

 vation, brought by Dr. Hayden, but have never been able to 

 obtain flowers, \uttall says the flowers are solitary and 

 Mnall ; in the specimen before me they are nearly 2 inches in 



