SCIENTIFIC PAPERS. 
ILLUSTRATED STUDIES IN THE GENUS OPUNTIA—IV. 
BY DAVID GRIFFITHS. 
Among a thousand members of the genus Opuntia collected 
between Ejutla and the Canadian boundary, now in cultiva- 
tion, the following appear not to have been previously de- 
scribed : 
Opuntia Bentonii, sp. nov. 
An open-branching, erect species, closely resembling O. Lindheimeri 
in habit; joints distinctly obovate, 17 to 18 by 27 to 28 cm. (last year’s 
growth), thin, with vascular system distinctly traceable for two or 
three years, dull dark green; areoles elliptical to obovate, 5 to 6 mm. 
long, tawny when young but soon becoming black; leaves subulate, 
cuspidate-pointed, recurved, 5 mm. long; spicules yellow, unequal, 
scattered in upper portion of areole and fringing it or scattered through 
its entire area; spines not numerous, confined to an irregular distribution 
on edges of joints, yellow, annular, translucent, bonelike, flattened, 
erect to recurved, 1 to 4 or 5, longest 244 cm. long and others shorter; 
flowers light yellow, large, 9 to 10 cm. in diameter, petals broadly 
obovate, rounded, mucronate, filaments greenish yellow, pistil 3 cm. 
long, style greenish white, stigma yellowish green, 7-parted; ovary 
obovate, slightly tuberculate when young, about 5 cm. long, with 
sub-circular areoles 2 to 3 mm. in diameter, bearing yellow spicules 
and a few fugacious, yellow, delicate spines; fruit obovate-pyriform, 
purplish red throughout, insipid, umbilicus broad, flat, slightly raised 
to slightly depressed with a slight pit in center. 
The species is most closely related to O. texana, but differs 
in shape, thickness and texture of joints, distribution and 
number of spines, and other minor details. It has turned 
up frequently during the past six years from Fernandina, 
Florida, to the mouth of the Brazos, always in cultivation 
in the eastern portion of this range and native in southwest- 
ern Louisiana and Texas. The first collection of it was made 
at McClenny, Florida, April 26, 1906, by Mr. Harmon Ben- 
(25) 
