212 



THE CACTACEAE. 



numerous, conspicuous on account of the densely crowded long bristles, especially on the older 

 joints, the marginal ones, at least, armed; spines very slender, solitary or 2 together, reddish or 

 red, at maturity gray, mostly 2 to 6 cm. long, nearly terete, scarcely spirally twisted; flowers sev- 

 eral on a joint; sepals lanceolate, acute or slightly acuminate; buds sharply pointed; corolla bright 

 yellow, 5 to 8 cm. wide; petals obovate, cuneate, notched, and prominently apiculate, 3 cm. long, 

 scarcely erose; stigma-lobes cream-color; berries obovoid, 2 to 3 cm. long, more or less flushed with 

 reddish purple, many-seeded; seeds about 4 mm. in diameter. 



FIG. 274. Opuntia argentina. 



FIG. 275. Opuntia chaffeyi. Photograph 

 by Senor Don Teodoro Chairez. 



Type locality: Fort Pierce, Florida. 



Distribution: Inland sand-dunes (scrub), peninsular Florida. 



The plant was first collected by Dr. Small near Fort Pierce, Florida, in 1917, and again 

 studied by him in its more northern range west of St. George in 1918. He describes it as 

 the most conspicuous native prickly pear of Florida, always viciously armed and with a char- 

 acteristically unjointed trunk. In spite of its many slender spines, cattle browse upon it. 



Illustration: Journ. N. Y. Bot. Card. 20: pi. 224. 



