GYMNOCALYCIUM. 
153 
KEY to Species — continued. 
BB. Ribs with prominent tubercles. 
C. Flowers with a very short tube. 
Spines brown to black. 
Central spines one or more. 
Tubercles without a distinct chin. 8. G. saglione 
Tubercles with a large chin. 9. G.mostii 
Central spines wanting. 10. G. gibhosum 
Spines yellow. 
Ribs 10 to 15. 11. G. multiflorum 
Ribs 22. 12. G. brachyanthum 
CC. Flowers with more or less elongated tube. 
Spines yellow, at least when young, or white. 
Spines 5 to 7, tortuous, up to 6 cm. long. 13. G. anisitsii 
Spines a little curved, 1 to 4 cm. long. 
Spines 10 to 13. 
Spines slender, not appressed. 14. G. monvillei 
Spines stout, appressed. 15. G. melanocarpum 
Spines 3, rarely more. 16. G. Uruguayense 
Spines brown. 
Central spines present. 
Ribs acute. 17. G. megalothelos 
Ribs obtuse. 18. G. kurtzianum 
Central spines none. 
Spines slender, acicular. 
Plant dark green. 19. G. damsii 
Plant reddish or bronze. 20. G. platense 
Spines stout, subulate. 
Flower-tube as long as limb; flowers sublateral. 21. G. schickendantzii 
Flower-tube much shorter than limb; flowers central. 22. G. stuckertii 
AAA. Species not grouped. 23. G. joossensianum 
Fig. 159. —Gymnocalycium mihanovichii. Fig. 160. — Gymnocalycium netrelianum. 
1 . Gymnocalycium mihanovichii (Fric and Giirke). 
Echinocactus mihanovichii Fric and Giirke, Monatsschr. Kakteenk. 15: 142. 1905. 
Plant somewhat depressed, 5 cm. in diameter or less, grayish green; ribs 8, prominent, acute; 
areoles small, 12 mm. apart; spines 5 or 6, spreading, yellowish; flowers about 3 cm. long; outer 
perianth-segments brownish green; inner perianth-segments green to yellowish green, sometimes 
tinged with red; scales on the slender flower-tube and ovary broad. 
