Voi,. II.] 



CACTUS FAMILY 



i. Opuntia Opuntia (I,.) Coult. 



Eastern Prickly Pear. Indian 



Fig. (Fig. 2527.) 



Cactus Opuntia L. Sp. PI. 468. 1753. 

 Opuntia vulgaris Mill. Gard. Diet. Ed. 8, 



no. i. 1768. 

 Opuntia Opuntia Coult. Contr. Nat. Herb. 



3:432. 1896. 



Prostrate, or ascending, joints obovate, 

 oblong, oval or orbicular, 2 / -5 / long. 

 Leaves subulate, appressed or somewhat 

 spreading, 2 // -4 // long, usually early de- 

 ciduous; bristles greenish or yellowish 

 brown; spines, when present, solitary, 

 grayish or variegated, stout, not deflexed, 

 3 f '-i%' long, often wanting; flowers yel- 

 low, sometimes with a reddish center, 

 2'-3' broad; fruit obovoid, fleshy, edible, 

 I'-iJ^' long, red. 



In dry sandy soil, or on rocks, eastern 

 Massachusetts to eastern Pennsylvania and 

 Florida. June-Aug. 



3. Opuntia tortispina Engelm. 



Twisted-spined Cactus. 



(Fig. 2529.) 



Opuntia tortispina Engelm. Pac. R. R. 

 Rep. 4: 21. 1856. 



Stems prostrate, the orbicular-obo- 

 vate flattened joints 6 / -8 / long. Spines 

 3-5, white, angled and channeled, 

 sometimes twisted, the longer ones 

 I K / -2> / long, with 2-4 more slender 

 and shorter ones; flowers sulphur-yel- 

 low, 2^ / ~3 / broad; fruit ovoid, fleshy, 

 unarmed, about 2' long and i' in diam- 

 eter; seeds orbicular, slightly notched 

 at the hilum, 2 // -3 // wide. 



Plains of Nebraska to Texas. 



2. Opuntia humifusa Raf. Western 

 Prickly Pear. (Fig. 2528.) 



Cactus humifusus Raf. Ann. Nat. 15. 1820. 

 Opuntia humifusa Raf. Med. Bot. 2: 247. 1830. 

 O. mesacantha Raf. ; Ser. Bull. Bot. Gen. 216 1830. 

 O. J?q/inesgutil$nge}m. Pac. R. R. Rep. 4: 41. 1856. 



Prostrate, similar to the preceding species; 

 joints obovate to suborbicular, or oval, usually 

 deep green, 3 / -5 / long; leaves subulate, spread- 

 ing. 3 // -5 // long; bristles reddish brown; spines 

 few, mostly near the margins of the joints, i- 

 4 together, whitish, or reddish at base and 

 apex, deflexed, or the longer one spreading 

 and Yz'-V long; flowers yellow, often with a 

 reddish centre, 2%'~3% f broad; fruit club- 

 shaped, not spiny, fleshy, edible, i^ / -2 / long. 



In dry sandy or rocky soil, Minnesota to Ken- 

 tucky, Missouri and Texas. Summer. A variable 

 species, of which several varieties are described. 



