126 



THE CACTACKAK. 



undulate; areoles 2 to 3 cm. apart, small, brown-felted; spines 2 to 6, acicular, brown, swollen at 

 ba-^e, unequal, the longest 2 em. long; flowers and fruit unknown. 



Collected near Barrinha, Bahia, Brazil, by Rose and Russell, June 8, 1915 (No. 19808). 



This is a very distinct and remarkable plant. In the shape and color of the branches 

 it suggests some species of Hyloccrcus such as H. ocamponis, but it is a true terrestrial and 

 never develops aerial roots. It is inconspicuous, growing in the bushy flats, and easily 

 overlooked. Numerous cuttings were sent to the New York Botanical Garden by Dr. 

 Rose, but only one of these lived, and this has not yet made any new growth. It may not 

 be of this genus, for it does not resemble closely any of the described species. 



Figure 187 is from a photograph taken by Paul G. Russell in 1915 at the type locality. 



FIG. 187. Acatlthocereus ( 3 ) albicaulis. 



FIG. 186. Acanthocereus brasiliensis. 



DESCRIBED SPECIES, PERHAPS OF THIS GENUS. 

 CEREUS TENELLUS Salm-Dyck in Pfeiffer, Enum. Cact. 109. 1837. 



Suberect, slender, 8 to 12 mm. in diameter; ribs 4 or 5, thin, compressed; areoles 8 to 10 mm. 

 apart; spines setiform, brown, short, 6 to 8 mm. long; flowers and fruit unknown. 



Type locality: Brazil. 



'I his species is not known to us from the incomplete description. 



Pfeiffer refers here as a synonym C. caiiJclabrins (Enum. Cact. 109. 1837). 



