92 



THE CACTACEAE. 



top of the plant; flower 2.4 to 2.6 cm. long, a little broader when fully expanded, white; fruit nearly 

 naked, globular, 4 to 6 mm. in diameter, thin-walled; seeds large, 2 to 2.5 mm. broad, somewhat 

 pointed at base, angled on the back; hilum large, sub-basal. 



Type locality: Between the lower hills near Santa Fe, New Mexico. 



Distribution: Rare in isolated localities in northern New Mexico; reported from 

 California by Watson (Cact. Journ. 1 : 43), probably erroneously. 



This is a remarkable plant whose generic position has been uncertain. Engelmann, 

 who first described it as a Mammillaria and afterwards as an Echinocactus, associates it 

 with Echinocactus simpsonii, that is, Pediocactus simpsonii, as representing a small group 

 of Echinocactus "with the appearance of Mammillaria." 



It has been reported only a few times and the fruit has not heretofore been described. 



Fendler reported it growing in loose red sandy fertile soil. 



In 1893 (Zoe 3: 301) Mr. M. E. Jones published a note on this species and, on the basis 

 of it, the plant has been admitted into the flora of Utah. He writes as follows: 



"The flowers are an inch long, opening but little; stigma cleft a line deep into 6 anther-like 

 divisions, papillose on the sides and upper surface ; filaments 6 lines long ; style almost as long as the 

 petals, yi a line thick, linear; the flowers open in the morning, and close in the afternoon, but appar- 

 ently are not affected by cloudy weather. This grows in alkaline soil, and blooms in May. It is 

 scarce everywhere." 



He wrote in a letter (March 18, 191 8) from Salt Lake City: 



"The material that I thought was this species came from the desert west of here, towards Mount 

 Ibapah. I remember very distinctly the appearances of the specimen but I did not collect it and I 

 now have some doubts about its identity. The spines were papery. I have never seen it since, 

 though I have hunted for it." 



We have found a similar plant in the herbarium of the Philadelphia Academy of 

 Sciences, collected by Siler in Utah, but it certainly is not the true E. papyr acanthus. This, 

 however, is only a slice from the plant and is without flowers or fruit; it may be described 

 as follows : 



Covered by a mass of spines; ribs numerous, low, tubercled; areoles close together, circular, 

 white-felted when young; radial spines 10 to 12, white, about 10 mm. long, weak; central spines 

 3 to 5, weak and flexible, more or less twisted, 2 to 3 cm. long; some of them more or less flattened, 

 pale or dark brown, one more or less hooked. A. L. Siler's note is as follows: "Only a few specimens 

 have ever been found. Flowers of this were pink, not white, as described by Engelmann. Southern 

 Utah, 1888." 



Illustration: Cact. Journ. 1: pi. v, as Echinocactus papyr acanthus. 



7. EPITHELANTHA* Weber. 



Plant globular, very small, the surface divided into numerous tubercles arranged in spiraled 

 rows, mostly hidden by the numerous small spines ; flowers very small, from near the center of the 

 plant, arising from upper part of the spine-areole on the young tubercles; outer perianth-segments 

 3 to 5; inner perianth -segments few, often only 5; stamens few, usually 10, included; fruit small, 

 clavate, red, few-seeded; seeds black, shining, rather large, with a large depressed hilum. 



Type species : Mammillaria micromeris Engelmann. 



We recognize one species, from western Texas and northern Mexico. 



The generic name is from exi on, drjXrj nipple, and avdos flower, indicating that 

 the flower is borne on the tubercle. 



This genus has heretofore been associated with the so-called Mammillaria, some of the 

 species of which it resembles in its globose shape and small clavate red fruits. On account 



*The name Epithelantha was given by Weber (Diet. Hort. Bois 804. 1898) as a synonym of Mammillaria 

 micromeris and therefore was not formally published by him. 



