STANDLEY TREES AND SHEUBS OF MEXICO. 939 



Globose to short-cylindric, 5 to 8 cm. broad; ribs numerous, 30 to 55, thin, 

 wavy ; areoles at first lanate, afterwards nalted ; spines 5, the upper one thin, 

 compressed, sometimes 3-toothed at apex, S to 33 mm. long, reddish with a 

 black tip, the other 4 spines spreading, more or less appressed, straight or 

 recurved, gray or reddish with black tips, much shorter than the upper one ; 

 flowers greenish yellow, 1.5 cm. long; inner perianth segments short-oblong, 

 obtuse, the outer ones more or less acute or apiculate ; scales on the ovary 

 broadly ovate with a scarious margin and a more or less prominent cusp. 



19. Echinofossulocactus phyllacanthus (Mart.) Lawrence in Loud. Gard. 

 Mag. 17: 317. 1841. 



Echinocactus phyllacanthus Mart. Allg. Gartenz. 4: 201. 1836. 



Echinocactus phyllacanthoides "Leva. Cact. Hort. Monv. 28. 1839. 



Central Mexico. 



Simple, depressed-globose to short-cylindric, 3 to 15 cm. high, 4 to 10 cm. 

 in diameter, dull green ; ribs 30 to 35, thin, undulate ; areoles only a few 

 to a rib, wiiite-tomentose wlien young ; spines 5 to 9 ; upper spine, or rarely 

 2 spines, much elongate, erect or connivent over the top of the plant, flattened, 

 thin, somewhat annulate, 4 cm. long; other spines weak-subulate, usually 

 pale and spreading ; flowers 15 to 20 mm. long, yellowish ; inner perianth seg- 

 ments acute. 



20. Echinofossulocactus lancifer (pietr.) Britt. & Rose, Cactaceae 3: 

 118. 1922. 



Echinocactus lancifer Dietr. Allg. Gartenz. 7: 154. 1839. 



Echinocactus dietrichii Heynhold, Nom. 2: 92. 1846. 



Mexico, the locality not known. 



Nearly ovoid, somewhat depressed at apex ; ribs numerous, strongly com- 

 pressed, undulate; areoles few to each rib, when young tomentose; spines 

 S, white or brownish at apex, some of them broad and flat ; flowers rather 

 large, rose-colored ; flower tube described as long ; perianth segments linear- 

 oblong, widely spreading. 



21. Echinofossulocactus gladiatus (Link & Otto) Lawrence in Loud. Gard. 

 Mag. 17: 317. 1841. 



Echinocactus gladiatus Link & Otto, Wochenschr. Ver. Beford. Gartenb. 

 3: 426. 1827. 



Probably native of eastern Mexico. 



Plant glaucescent, ovoid to oblong, 12.5 cm. high, 10 cm. in diameter with 

 a depressed apex covered with connivent spines ; ribs prominent, rather 

 broad, obtuse, 14 to 22 ; spines 10, gray, 4 upper spines subulate^ of these 3 

 usually ascending, the central spreading or porrect, the largest 5 cm. long, 

 4 lower spines acicular. 



22. Echinofossulocactus confusus Britt. & Rose, Cactaceae 3: 120. 1922. 

 Native of Mexico, the range not known. 



Simple, pale green, stout, columnar to short-clavate, 6 to 15 cm. high, 6 

 to 8 cm. in diameter ; ribs 26 to 30, thin, low, wavy ; areoles 4 or 5 on each 

 rib, 2 to 3 cm. apart; spines all yellow, subulate; radial spines 4 or 5, only 

 slightly flattened, 7 to 10 mm. long; central spine solitary, up to 4 cm. long, 

 usually porrect ; flowers purplish, 4 cm. broad ; perianth segments oblong, 

 acute. 



The following species of Echinocactus are perhaps referable to Echinofos- 

 sulocactus, but they are still imperfectly unknown : E. acanthion Salm-Dyck. 

 E. acroacanthus Stieber, E. adversispinus Miihlenpf., E. hrachycenirus Salm- 

 Dyck, E. cereiformis DC, E. debilispinus Berg, E. ellemectii Berg, E. flexuosus 



