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DAVID GRIFFITHS 



late Professor Bernard Mackensen,^ that Lindheimer considered 

 that he was deahng with two species in southern Texas for his 

 material is marked, ''Die grosse Opuntia," and ''Die kleine 

 Opuntia," referring, presumably, in the one case to Opuntia 

 Lindheimerii and in the other to Opuntia macrorhiza. Dr. 

 Engelmann must have been influenced greatly in his determina- 

 tion of species by the opinion of his collector, who was the only 

 one at that time who had a field knowledge of the species. My 

 investigations show clearly that the upper Guadaloupe and New 



Fig. 1. Two joints with ripe fruits of Opuntia macrorhiza grown at Chico, 

 i,lifornia. One-eighth natural size. 



California 



Braunfels tuberous-rooted Opuntias are entirely different species, 

 although I believe it is quite possible that the true Opuntia 

 macrorhiza may be found on the Edwards Plateau not far from 

 New Braunfels. 



In the Cactaceae of the Mexican Boundary Survey Dr. 

 Engelmann seems to have ignored the upper Guadaloupe mate- 

 rial entirely, for in his notes he speaks of the species "between 

 San Antonio and Austin (Lindheimer)" and in his figures this is 



2 Bull. Torr. Bot. Club. 39: 289-290. 1912. 



