ILLUSTRATED STUDIES IN THE GENUS OPUNTIA.—IV. 35 
vation, the spines are much more numerous than indicated in 
the description, which was drawn from the type plant. They 
are, however, tardy in their development, appearing mostly 
the second year. By the third year, the plant is really very 
spiny under cultivation. 
As stated, the description is mainly from the type plant, 
but notes have been kept for three years on the species under 
cultivation. 
The type specimen is number 9338 D. G., collected near 
Lampasas, Texas, July 3, 1908, together with some put up 
later from material grown from cuttings of the type plants. 
It inhabits the valley lands and is one of the largest species 
of the region. Under cultivation at San Antonio, Texas, it 
has bloomed very sparsely the second year, from single joint 
cuttings.—Plates 11, above, and 15. 
Opuntia gilvoalba, sp. nov. 
A low erect to ascending species, about 1 m. high and 1 to2 m. in 
diameter, with branches frequently on edge on ground and others erect 
from them, hemispherical in outline when fully developed; joints obo- 
vate, broadly to sharply pointed above and contracted and almost stipi- 
tate below, yellowish green, about 18x 20 cm., thin; areoles large, 
prominent, brown, turning to dirty gray, and finally black, obovate 
becoming subcircular, 8-10 mm. in diameter, and about 5 cm. apart; 
spicules prominent, scattered, unequal, about 1 cm. long, diverging in 
all directions; spines yellow, stout, annular, diverging in all directions 
but mostly sloping downward, flattened, seldom twisted, 2 to 2.5 cm. 
long, increasing somewhat both in length and numbers. 2 to 6 mostly 
about 4; flowers yellowish white, large and showy, about 10 cm. in 
diameter when fully opened, petals narrowly obovate with a promi- 
nent cuspidate point, style and filaments white, stigma light green; 
fruit purplish-red, obovate-pyriform, about 3460 mm., raised at 
areoles when young, but this disappearing when fully mature, bearing 
small subcircular areoles with a tuft of divergent spicules the largest 
of which may be 1 cm. long, these dropping off early, leaving the 
areole dirty gray. 
The species inhabits the brushy, low elevations in the salt 
marshes of the delta of the Rio Grande. It is readily recog- 
nized by its joint and flower characters. The color of the 
flowers is a very light yellow, almost white, with possibly a 
tinge of green. It almost exactly matches that of Opuntia 
