122 THE CACTACEAE. 



EchinocacTUS griseispinus Jacobi, Allg. Gartenz. 24:99. 1856. 



Stems clavate, 15 cm. high, 10 cm. in diameter, glaucescent, somewhat umbilicate at apex; 

 ribs 34 to 38; radial spines 7; 3 upper spines erect, when young purple with black tips, about 2.5 cm 

 long; lower spines white; central spine solitary, 2.5 cm. long or more. 



Echinocactus hexacanthus Miihlenpfordt, Allg. Gartenz. 14:369. 1846. 



Obovate, umbilicate at apex; ribs 34, flattened; radial spines 5; central spine solitary. 



Echinocactus heyderi Dietrich, Allg. Gartenz. 14: 170. 1846. 



Obovate, pale green, rounded at apex; ribs numerous, strongly compressed; spines 8, grayish 

 white; central spine solitary, terete, porrect. 



Echinocactus hookeri Miihlenpfordt, Allg. Gartenz. 13:345. 1845. 



Obovate; ribs numerous; upper spines flattened, incurved, 5 cm. long; radial spines whitish, 

 16 mm. long. 



Echinocactus hystrichocentrus Berg, Allg. Gartenz. 8: 131. 1840. 



Echinocactus hystrichodes Monville in Labouret, Monogr. Cact. 215. 1853. 



Clavate, 10 cm. high, somewhat umbilicate at apex; ribs 39, compressed, wavy; areoles only a 

 few to each rib; spines 8, all flat and thin; the 3 upper larger, whitish gray with black tips; central 

 spine solitary, erect, incurved, annulate. 



Echinocactus linkeanus Dietrich, Allg. Gartenz. 16: 298. 1848. 



Spines 6, white; radial spines 5; central spine solitary, flat, variously curved. 



Echinocactus macrocephalus Miihlenpfordt, Allg. Gartenz. 14: 370. 1846. 



Subglobose, light green, depressed at apex; ribs 34, somewhat acute, undulate; areoles 5 cm. 

 apart; radial spines 7 or 8; the 3 upper ones elongated; the 4 lower ones short; central spine solitary, 

 erect. 



Echinocactus mammillifer Miquel, Linnaea 12: 8. 1838. 



This seems to be a seedling and may belong to some species of this genus. Its strongly com- 

 pressed ribs certainly suggest this genus. Miquel does not state where his plant came from, but 

 suggests a relationship with Pfeiffer's second group to which Echinocactus scopa and other South 

 American species belong ; it does not seem to us to belong with it. Schumann did not know the species. 

 Echinocactus theiacanthus Lemaire (Cact. Gen. Nov. Sp. 86. 1839) which was originally spelled 

 E. theionacanthus Lemaire (Cact. Aliq. Nov. 22. 1838) was taken up by Lemaire as E. mammillifer. 

 This is further discussed on page 137. 



Echinocactus ochroleucus Jacobi, Allg. Gartenz. 24: 101. 1856. 



Stems eylindric to clavate, 10 cm. high, 7.5 cm. in diameter, light green, somewhat umbilicate 

 at apex; ribs 2>i to 36, acute; areoles only a few to each rib; spines 7, yellowish; 3 upper spines 3 cm. 

 long, erect; 4 lower spines very short. 



Echinocactus octacanthus Miihlenpfordt, Allg. Gartenz. 16: 10. 1848. 



Obovate ; ribs 40 to 44, compressed ; areoles with white hairs when young ; radial spines 7 ; 

 central spine solitary. 



Echinocactus quadrinatus Wegener, Allg. Gartenz. 12: 66. 1844. 



Echinocactus wegeneri Salm-Dyck, Cact. Hort. Dyck. 1849. 31. 1850. 

 Plant subcylindric, 7.5 cm. high, 5 cm. in diameter; ribs 34 to 36, strongly compressed; areoles 

 remote, somewhat velvety when young; spines usually 7 ; 3 upper spines subulate, angled, the middle 

 one shorter; central spine solitary, grayish brown, sometimes wanting; lower spines 4, recurved, 

 reddish white, the 2 lowermost ones a little longer. 



Kchinocactus RAPHIDACANThus Salm-Dyck, Cact. Hort. Dyck. 1849. 160. 1850. 



Stems globose, light green; ribs 35 to 40, strongly compressed; young areoles white, velvety, 

 upper and central spines 4, stout, yellowish red, the uppermost one broad and flat; lower spines 6; 

 slender, white. 



Echinocactus raphidocentrus Jacobi, Allg. Gartenz. 24: 101. 1856. 



Plant depressed-globose, 5 cm. high, 6 cm. in diameter, light green, somewhat umbilicate; 

 ribs 24 to 28, acute; radial spines 7, the 3 upper ones reddish brown. 



