STANDLEY TREES AND SHRUBS OF MEXICO. 973 



6. Escobaria lloydii Britt. & Rose, Cactaceae 4: 57. 1923. 



Zr.catecas, the type from the Sierra Zuluaga. 



Plants growing in clumps and resembling a small species of Echinocere us ; old 

 plants bearing naked corky tubercles ; radial spines about 20, spreading, 

 slender, white; central spines several, stout, with black or brownish tips, 2 cm. 

 long ; flowers greenish, with a central stripe on the outside, 2.5 cm. long ; fruit 

 red, globose to short-oblong, 6 to 12 mm. long ; seeds black, pitted, globose, 1 

 mm. in diameter. 



DOUBTFUL SPECIES. 



Mammillaria emskoetteriana Quehl, Monatsschr. Kakteenk. 20: 139. 1910. 

 Perhaps a species of Escobaria. Type supposed to have come from San Luis 

 Potosi. 



46. BARTSCHELLA Britt. & Rose, Cactaceae 4: 57. 1923. 



A single species is known. 



1. Bartschella schumannii (Hildm.) Britt. & Rose, Cactaceae 4: 58. 1923. 



Mammillaria schumaunii Hildm. Monatsschr. Kakteenk. 1: 125. 1891. 



Mammillaria veniista K. Brandeg. Zoe 5: 8. 1900. 



Southern Baja California. 



More or less cespitose (as many as 40 stems have been reported in a single 

 cluster), 6 cm. high or less; axils slightly woolly, without bristles; radial 

 spines 9 to 15, stout, 6 to 12 mm. long, brownish above, glabrous ; central 

 spines usually 1, sometimes 2 or 3, one of these usually hooked; in seedlings 

 10 or 11 radial spines developing, these spreading, feather-like, with long 

 spreading hairs ; in plant one year old the spines simply puberulent, all white 

 with brown tips and one central much longer than the others and strongly 

 hooked ; flowers 3 to 4 cm. in diameter, the segments about 10, lance-acuminate; 

 stamens numerous, erect, shorter than the style ; style slender, erect, pale ; 

 stigma lobes 6, linear, green ; fruit short, dull ; seeds usually found in a cup 

 in between the tubercles, less than 1 mm. long. 



47. PELECYPHOBA Ehrenb. Bot. Zeit. 1: 737. 1843. 

 A single species is known. 



1. Pelecyphora aselliformis Ehrenb. Bot. Zeit. 1: 737. 1843. 



San Luis Potosf. 



Tufted, cylindric, 5 to 10 cm. high, 2.5 to 5 cm. in diameter, covered with 

 tubercles arranged in spirals; tubercles strongly flattened laterally, some- 

 what stalked at base; areoles at top of the tubercles very long and narrow, 

 crowned by an elongate scale-like spine with numerous lateral ridges usually 

 free at tip, giving a peculiar pectinate appearance; flowers 3 cm. bi*oad or 

 more, campanulate ; perianth segments in 4 rows, the outer ones sometimes 

 white, oblong, acute ; flower tube proper very short ; stamens borne at the 

 top of the flower tube, much shorter than the perianth segments ; stigma lobes 

 4, erect ; seeds 1 mm. broad, kidney-shaped. " Peyote," " peyotillo." 



The plant is employed locally as a remedy for fevers. 



48. DOLICHOTHELE Britt. & Rose, Cactaceae 4 : 61. 1923. 



Plant body globose, more or less cespitose, soft in texture, never milky; tu- 

 bercles elongate, not grooved above ; flowers borne in the axils of old tubercles, 

 very large, with a definite funnel-shaped tube; inner perianth segments yel- 

 low, spatulate, tapering into a claw and borne on the top of the tube ; stamens 

 forming a spiral about the style and borne on the whole face of the throat 



79688—24 9 



