144 



Descriptive Flora 



Echinocactus setispinus Engelm. Hedgehog Cactus 



Twisted-rib Cactus 



Cactus with a thick, fleshy, globular, egg or barrel-shaped 

 stem (2 to 4" across, 2 to 12" high) and 13 narrow oblique ribs. 

 Ribs are wavy or bluntly toothed on margin, each lobe or tooth 

 bearing a cluster of slender spines at its summit. Each cluster of 

 spines has 14 to 16 radiating and spreading, bristle-like spines, 

 and 1 to 3 slender, central, darker ones, each 1 to \y<£ long. 

 Flowers yellow, with red centers, 2 to 3" across, blossoming 1 to 6 

 at a time out of the center of the plant. Petals many, yellow 

 with red bases. Stamens numerous, thread like. Stigma 10- 

 lobed, yellow, the tips spreading over the anthers. Fruits bright 

 coral-red. These plants blossom every few days from April to 

 July, sometimes as late as September. The plants have the 

 characteristic habit of growing close to the base of mesquite 

 trunks. 



Young plants up to about an inch across, are easily mistaken 

 for another species as they do not resemble the mature plant. 

 They are globular, with tubercules radiating in all directions, 

 each tubercle tipped with a tuft of spines and when very young 

 with white hairs. As the plants become older, the tubercles 

 flatten and form the 13 ribs characteristic of the mother plant. 



Uchinocactus texensis Hoepf. Devil's Head. 



Spiny plants, solitary or two together, 1 to 3" above the 

 ground, much more of it below the surface, 4 to 12 inches across, 

 with 13 to 25 thick ribs (depending on size of plants), each rib 

 bearing 1 or 2 clusters of spines. Each cluster consists of 7 stout, 

 pinkish thorns, the central one by far the largest and curving 

 away from the central axis, the other six radiating and spreading. 

 Flowers delicate pink or yellowish-rose, frilled at the tips of the 

 petals, shading to deeper pink or red in the cup, which is set in 

 a densely woolly involucre consisting of many rows of slender, 

 reddish, spine-tipped bracts. Stamens numerous, with threadlike 

 filaments and very small inconspicuous stamens. Stigma orange 



