28 THE CACTACEAE. 



Otto Kuntze made the binomial Cactus engelmannii because, as he states, the name 

 Mammillaria recurvispina De Vriese had priority over Engelmann's name. Engelmann, 

 however, had long before renamed his plant. 



Mammillaria nogalensis Riinge (Schumann, Gesamtb. Kakteen 494. 1898) has been 

 referred here as a synonym, but this name had already been used by Walton. 



Illustrations: Schelle, Handb. Kakteenk. 239. f. 156, as Mammillaria recurvata; Cact. 

 Journ. i: pi. for March; 2: 148; pi. for September, as M. nogalensis. 



Figure 26 is from a photograph by Dr. MacDougal at Calabasas, showing a clump; 

 figure 27 is from a photograph of a plant sent by F. J. Dyer from Nogales. 



5. Coryphantha poselgeriana (Dietrich). 



Echinocactus poselgerianus Dietrich, Allg. Gartenz. 19: 346. 1851.* 



Echinocactus sallillensis Poselger, Allg. Gartenz. 21: loi. 1853. 



Echinocactus salinensis Poselger, Allg. Gartenz. 21: 106. 1853. 



Mammillaria difficilis Quehl, Monatsschr. Kakteenk. 18: 107. 1908. 



Mammillaria valida J. A. Purpus, Monatsschr. Kakteenk. 21: 97. 191 1. Not Weber, 1898. 



Plant-body large for the genus, globular, bluish green ; tubercles large, closely packed together 

 and at base strongly angled; radial spines of two kinds, the 4 or 5 lower ones spreading, subulate, 

 reddish to black, about as long as the single central one (2 to 4 cm. long) ; the upper radials, 5 to 

 8, ascending together, yellowish with black tips, weak, acicular; flower large, 4 to 5 cm. long and 

 nearly as broad when expanded, flesh-colored, the segments spatulate, usually rounded at apex; 

 fruit oblong, 15 mm. long; seeds brownish. 



Type Species: Near Saltillo, Mexico. 



Distribution: States of Nuevo Leon, Coahuila, and Zacatecas, Mexico. 



Two different plants have been passing under the name Echinocactus saltillensis . The 

 one now in the trade, called E. ingens var. saltillensis by Schumann, is a very large plant 

 and is a true Echinocactus which we have already elsewhere described as E. palmeri]] the 

 other, which is the one originally described by Poselger, is a small globular Coryphantha 

 and has usually been taken for Mammillaria scheeri, more recently described as M. valida. 



The clusters of connivent weak spines, so characteristic of this species, are not always 

 shown in young plants and this may account for certain seeming discrepancies in the ori- 

 ginal descriptions. The nascent spines are sometimes red, bleaching white; the gland in 

 the groove of the tubercle is bright red. 



Illustrations: De Laet, Cat. Gen. f. 44; Schelle, Handb. Kakteenk. 239. f. 157; Tri- 

 bune Hort. 4: pi. 139; Rev. Hort. Belg. 40: after 196, as Mammillaria radians; Monatsschr. 

 Kakteenk. 21: 99, as Mammillaria valida; (?) Blanc, Cacti 50. No. 599; (?) Cact. Journ. 

 2: 55, as Echinocactus poselgerianus; Monatsschr. Kakteenk. 18: 107, as Mammillaria 

 difficilis; Rother, Praktischer Leitf aden Kakteen 3 1 , as Echinocactus scheeri. 



6. Coryphantha muehlenpfordtii (Poselger). 



Mammillaria scheeri Miihlenpfordt, Allg. Gartenz. 15: 97. 1847. Not Miihlenpfordt, 1845. 

 Echinocactus muehlenpfordtii Poselger, Allg. Gartenz. 21: 102. 1853. 

 Mammillaria scheeri valida Engelmann, Proc. Amer. Acad. 3: 265. 1856. 

 Coryphantha scheeri Lemaire, Cactees 35. 1868. 

 Cactus scheeri Kuntze, Rev. Gen. PI. i: 261. 1891.* 



Plants nearly globular, usually simple, short-oblong, 20 cm. long, 7.5 to 15 cm. in diameter; 

 tubercles large, i to 2.5 cm. long; axils of young tubercles grooved and young spine-areoles very 

 woolly ; grooves bearing large dark-colored glands ; spines variable, reddish to yellow with brown to 

 black tips; radials 6 to 16, usually about 2 cm. long, straight; central spines i to 4, subulate, stouter 

 than the radials, 3 to 3.5 cm. long, from nearly straight to curved at tip or even strongly hooked; 

 flowers yellow, 6 cm. long; scales on flower- tube and outer perianth-segments more or less lacerated; 

 inner perianth-segments oblong, entire, acute; fruit greenish, oblong, 3 to 3.5 cm. long, naked; seeds 

 large, 3 mm. long, brown, shining, smooth. 



Type locality: Mexico. 



Distribution: Northern Chihuahua, western Texas, and southern New Mexico. 



* We have not seen the type of this species but Bodeker has sent us a copy of the photograph of it left by Poselger. 

 t See Contr. U. S. Nat. Herb. 12: 290. 1909; Britton and Rose, Cactaceae 3: 172. 1922. 



