214 



THE CACTACEAE. 



covered with stamens; tube-proper very short, i to 2 mm. long; style longer than the stamens, 

 stout, glabrous ; stigma-lobes about 8, 4 mm. long ; scales on the base of the flower-tube large, obtuse, 

 on the ovary scattered, minute, 1 to 2 mm. long; fruit at first bright magenta, with fleshy walls, 

 but becoming dry and thin-walled, oblong to pyriform, almost destitute of scales, 3.5 to 4 cm. long, 

 dehiscing by a large basal pore; seeds large, 4 mm. long, black, tuberculate; hilum sublateral, large. 



Type locality: At the head of the Mojave River, California. 



Distribution: Deserts of California and Nevada; reported from western Arizona. 



Engelmann in his original description states that the flowers are yellow, as Schumann 

 also states, while Coulter describes them as yellow or red. In our description based on sev- 

 eral collections we describe the flowers as magenta. In order to clear up the matter we 

 wrote to Mr. E. C. Rost, a very keen observer, who had recently had this plant under 

 observation; he replied under date of September 2, 192 1, as follows: 



"In regard to the flowers of E. polyancistrus, I will say that I have seen many of these plants 

 in blossom. My own color notes record the flower as having petals of a pure transparent 'madder- 

 lake' ; stamens bright yellow ; pistil crimson. The mature buds are the shade of burnt sienna, or 



Fig. 224. Sclerocactus polyancistrus. 



brownish red. These flowers, however, could be described as both purple and red, for on their first 

 day of bloom they are 'purple' (madder-lake), while on the second day and even more so on the 

 third day they would popularly be termed 'red.' A yellow polyancistrus I have never seen, 

 although the bright-yellow stamens sometimes protrude from the blossom in such a manner that a 

 person at a distance might think he saw a yellow flower. 



"I have never found the polyancistrus growing in a dense colony, but have always seen the 

 plants widely scattered, then for miles not a plant, and again a few growing here and there, rather 

 far apart. I have found them in various different localities." 



This species, while found over a large area, is said never to be abundant and is found 

 chiefly on the mesas. 



Illustrations: Pac. R. Rep. 4: pi. 2, f. 1, 2; Cact. Journ. 1: pi. V, in part; Monatsschr. 

 Kakteenk. 20: 131 ; 31: 21, as Echinocactus polyancistrus. 



