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. 



Tubercles with a large chin 9. 



Central spines wanting 10. 



Spines yellow. 



Ribs 10 to 15 11. 



Ribs 22 12. 



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. 



Spines a little curved, 1 to 4 cm. long. 

 Spines 10 to 13. 



Spines slender, not appressed 14. 



Spines stout, appressed 15. 



Spines 3, rarely more 16. 



Spines brown. 



Central spines present. 



Ribs acute 17. 



Ribs obtuse 18. 



Central spines none. 

 Spines slender, acicular. 



Plant dark green 19. 



Plant reddish or bronze 20. 



Spines stout, subulate. 



Flower-tube as long as limb ; flowers sublateral 21. 



Flower- tube much shorter than limb; flowers central 22. 



AAA. Species not grouped 23. 



G. saglione 

 G. mostii 

 G. gibbosum 



G. multiflorum 

 G. brachyanlhum 



G. anisitsii 



G. monvillei 



G. melanocarpum 



G. uruguayense 



G. megalothelos 

 G. kurtzianum 



G. damsii 

 G. platense 



G. schickendantzii 



G. stuckertii 



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. 



