MAEACOCARPTJS. 1 87 



Illustrations: Schelle, Handb. Kakteenk. 147. f. 73 ; Engler and Drude, Veg. Erde 8: pi. 

 15, f. 30; Schumann, Gesamtb. Kakteen f. 53, as Echinocactus ceratites; Cact. Mex. Bound, 

 pi. 33, f. 7, as Echinocactus sandillon. 



Figure 197 is from a photograph of a plant in the Botanical Garden at Santiago, Chile, 

 taken by Mrs. J. N. Rose, in 1914. 



23. MALACOCARPUS Salm-Dyck, Cact. Hort. Dyck. 1849. 24. 1850. 



Plants globose to short-cylindric, either simple or clustered; ribs definite, usually straight, either 

 entire or broken up into more or less definite tubercles ; areoles felted, especially when young, spine- 

 bearing ; flowers from the center of the plant, broad and short, mostly yellow ; perianth funnelform to 

 subrotate; stigma-lobes in typical species red; ovary densely covered with scales bearing an abun- 

 dance of wool and usually bristles in their axils; fruit soft, rose-red or crimson; seeds brown or 

 black, tuberculate with a broad truncate base; hilum white. 



Prince Salm-Dyck, who established the genus, assigned 6 species of Echinocactus to 

 it, of which E. corynodes Pfeiffer was the first and is therefore taken by us as the generic 

 type. 



Schumann treats the group as a subgenus of Echinocactus; he assigns 3 species to it, 

 all from the State of Rio Grande do Sul, Brazil; Arechavaleta, who follows Schumann's 

 treatment, describes 6 species from Uruguay. Besides those heretofore treated in the 

 subgenus Malacocarpus, we refer here most of the species assigned by Schumann to the 

 subgenus Notocactus. 



We recognize 29 species, all from South America and all found south of the Equator. 

 The generic name is from fiaXaKos soft, and napiros fruit, referring to the fleshy fruit. 



Key to Species. 



A. Plants globular to stout-cylindrie. 



B. Areoles of the ovary and flower-tube long-hairy or long-woolly. 

 C. Spines 4 cm. long or less, straight. 

 D. Flowers yellow. 

 Ribs acute. 



Spines subulate 1 . 



Spines acicular. 



Spines yellow 2. 



Spines white or becoming silvery. 



Spines 3 to 7 3- 



Spines 9 or 10 4- 



Ribs obtuse or rounded. 



Ribs spirally arranged, broken into tubercles. 



Spirals many ; plant gray 5. 



Spirals few ; plant brown 6. 



Ribs straight or nearly so, undulate or continuous. 

 Perianth short-funnelform. 



Perianth-tube very stout 7. 



Perianth-tube relatively slender. 



Plant deeply umbilicate ; spines slender 8. 



Plant slightly umbilicate; spines short 9. 



Perianth campanulate to subrotate. 

 Spines setaceous or acicular. 



Ribs 30 to 40; radial spines up to 40 or more 10. 



Ribs 21 or fewer; radial spines much fewer than 40. 



Ribs very low and rounded 11. 



Ribs prominent. 



Areoles only 4 to 7 mm. apart 12. 



Areoles more separated. 



Inner perianth-segments obtuse or merely apiculate 13. 



Inner perianth-segments acute or acuminate 14. 



Spines stouter, subulate. 



Inner perianth-segments 2 to 3 cm. long. 

 Spines terete. 



Spines slender, slightly curved 15. 



Spines stout, rigid 16. 



Spines flattened. 



Central spines not much longer than the radials 17. 



