FIjROCACTUS. 
139 
Echinocactus pfersdorffii Hortus may be referable here. It is probable that E. pfers- 
dorffii Hildmann Catalogue (Monatssehr. Kakteenk. 5: 92. 1905) is the same, but neither 
was accompanied by a description. 
In cultivation this plant is simple, depressed-globose, 4.5 dm. in diameter, but in the 
wild state sometimes cylindric and up to 6 dm. high, and described as proliferous; ribs 20, 
perhaps even more, acute; areoles rather large, distant; radial spines usually 8, subulate, 
somewhat curved, 4.5 cm. long; central spines usually solitary, but as many as 4 reported, 
all yellow. 
We have followed Schumann in refer¬ 
ring here various synonyms, but the indi¬ 
cations are that we have more than one 
species. Dr. Rose obtained flowers of this 
species at Da Mortola in 1912 and his notes 
were used in drawing up the description. 
Here belongs Cactus multangularis 
Mocino and Sesse (Mem. Mus. Hist. Nat. 
Paris 17: 38. 1828), but never described 
by them. Echinocactus electracanthus 
rufispinus (Monatssehr. Kakteenk. 3: 70. 
1893) we would also refer here. 
Echinocactus hystrichacanthus Demaire 
(Cact. Gen. Nov. Sp. 17. 1839) may be of 
this relationship. This species as well as 
E. pycnoxyphus Lemaire (Cact. Gen. Nov. 
Sp. 16. 1839) Weber considered as only 
varieties of E. hystrix. 
Illustrations: De Candolle, Mem. Mus. 
Hist. Nat. Paris 17: pi. 10, as Echinocactus 
melocactiformis; Monatssehr. Kakteenk. 3: 
158. f. 2; 21: 171; Schumann, Gesamtb. 
Kakteen f. 58, as Echinocactus electr acanthus; Bliihende Kakteen 1: pi. 22, as Echinocactus 
in gens. 
Figure 146 is copied from the first illustration above cited. 
22 . Ferocactus macrodiscus (Martius). 
Echinocactus macrodiscus Martius, Nov. Act. Nat. Cur. 16; 341. 1832. 
Echinocactus macrodiscus laevior Monville in Labouret, Monogr. Cact. 197. 1853. 
Echinocactus macrodiscus decolor Monville in Labouret, Monogr. Cact. 197. 1853. 
Echinocactus macrodiscus multiflorus R. Meyer, Monatssehr. Kakteenk. 24: 150. 1914. 
Simple, depressed-globose or sometimes short-cylindric, sometimes 4.5 dm. in diameter; ribs 16, 
perhaps more in some specimens, somewhat flattened, sometimes acute on the margin, somewhat 
depressed at the distant areoles; spines all yellow, more or less curved backward; radial spines 6 to 8, 
mostly 2 to 3 cm. long; central spines 4, stouter and flatter than the radials, 3.5 cm. long; flowers 
5 cm. long, dark red to purple, obconic; inner perianth-segments linear-oblong, acute; stamens and 
style included. 
Type locality: Not definitely cited but probably on the Cumbre at about 10,000 feet, 
in a place called HI Renosco, Mexico. 
Distribution: San Duis Potosi and southward. 
We do not know this species definitely although it is supposed to have a rather wide 
distribution in Mexico. The only specimen which we can refer with any confidence is 
one obtained through Professor Conzatti in 1910 from Oaxaca, Mexico. 
