CACTACE^E. (CACTUS FAMILY.) Ill 



upper ones a little shorter, central ones 1 to 3, bulbous at base, terete, a little 

 stronger, lowest one longest. Pac. R. Rep. iv. 34, t. 4. S. Colorado and 

 southward. 



5. C. conoideus, Big. Heads 3 to 4 inches high, few from one base, of 

 unequal height, ovate, acutish towards the apex, conoid : ribs 9 to 11: radial 

 spines 10 to 12, slender, rigid, upper ones 2 to 5 lines long, lateral ones 6 to 

 15 lines, upper central spines hardly longer than the lateral ones, lower one 1 to 3 

 inches long, angular and often compressed. Pac. R. Rep. iv. 36. S. Colorado 

 and southward. 



6. C. paucispinus, Eng. Stem 5 to 9 inches high, 2 to 3 inches in 

 diameter, ovate-cylindrical, sparingly branching or simple : ribs 5 to 7 : areoloe 

 remote: spines strong, 9 to 16 lines long, dark-colored, radial ones 3 to 6, central 

 wanting or rare, stout, subangled. Pac. R. Rep. iv. 34. S. Colorado and 

 southward. 



4. OPUNTIA, Tourn. 



Petals spreading or rarely erect. Berry succulent or sometimes dry, 

 marked with bristly or spiny areolse, truncate. Articulated much-branched 

 plants, of various shapes, low and prostrate, or erect and shrub-like. 



1. Joints compressed: rhaphe forming a prominent bony margin around the seed. 

 * Fruit pulpy. 



1. O. Camanchica, Eng. & Big. Large, prostrate, extensively spread- 

 ing : joints ascending, 6 to 7 inches long, suborbiculate : areolse remote, numer- 

 ous, armed : bristles straw-colored or brownish, few : spines 1 to 3, compressed, 

 brownish, paler at the apex, 1 to 3 inches long, upper ones elongated, suberect, the 

 others deflexed : berry large, ovate, widely umbilicate : seeds angled, deeply 

 notched at the hilum. Pac. R. Rep. iv. 40. S. Colorado and southward. 



2. O. Rafinesquii, Eng. Joints deep green, prostrate, broadly obovate or 

 orbicular : leaves spreading : bristles bright red-brown : spines few and small with 

 a single strong one: flowers sulphur-yellow, mostly with a red centre: berry 

 narrowed at the base, with a funnel-shaped umbilicus. Pac. R. Rep. iv. 43. 

 From Colorado eastward across the plains to Wisconsin and Kentucky. 



Var. (1) fusiformis, Eug. & Big. Roots forming fusiform tubers: bristles 

 stout and yellowish brown : flowers smaller and with fewer sepals : seed 

 larger and thicker. Pac. R. Rep. iv. 43. From the Missouri southward 

 across the plains. 



* * Fruit dry and prickly. 



3. O. Missouriensis, DC. Prostrate : joints broadly obovate and tuber- 

 culate, 2 to 4 inches long : leaves minute ; their axils armed with a tuft of straw- 

 colored bristles and 5 to 10 slender radiating spines I to 2 inches long: flowers 

 light yellow. Frequent on the plains and in the mountains, and extending 

 eastward to Wisconsin. 



4. O. rutila, Nutt. Prostrate, with thick obovate or elongated joints, 2 to 4 

 inches long, sometimes thick and almost terete : areolce close, armed with numer- 

 ous slender reddish or gray flexible spines : flowers purple : berry deeply umbili- 

 cate : seeds large, flat, broadly margined, ivory-white. Torr. & Gray, Fl. i. 

 155. S. Wyoming to Utah and westward. 



