ILLUSTRATED STUDIES IN THE GENUS OPUNTIA.—IV. 33 
but neither seedlings nor vegetatively propagated plants have 
borne fruit in this country. In no case have any of the plants 
even flowered» The type specimen is one prepared from a 
cultivated plant at Brownsville, Texas, October, 1910, and 
bearing my collection number 8101.—Plates 11, below, and 
12. 
Opuntia perrita, sp. nov. 
A low, caespitose, erect to ascending plant, about 20 to 80 cm. high 
and forming bunches 20 to 100 or more cm. in diameter; joints 15 to 
20 em. long and 2.5 to 3 em. in diameter, cylindrical or often more or 
less fusiform or clavate, tubercles prominent, with long slope down- 
ward and top of crest close to the areole or upper short slope, com- 
paratively narrow, about3 cm. long, 12 mm. wide and1 cm. high, hav- 
ing a darker green line almost completely surrounding it; areoles oval, 
about 4 X 8 mm. in central portion of joint but smaller above and below, 
often becoming confluent at apex, gray or tawny, flat, but may be 
slightly elevated on old joints; spicules light bright brown fading to a 
dirty yellowish brown on old stems, more prominent below, 1 to 2 mm. 
long but mostly scarcely visible above; spines long, conspicuous and 
formidable, light straw colored with loose sheath and spines about 
same color, 4 to 8, divergent, spreading in all directions, with lower 
ones more turned back than the others as well as smaller and often 
only half-sheathed, often 5 cm. long, flattened, including sheath fully 
2 mm. in diameter; flowers greenish yellow; fruits yellowish when 
mature, oval to obovate slightly narrowed above, 3.5 cm. long, bear- 
ing a single long straw-colored fugacious delicate spine in upper 
areoles, about 24 cm. long, sheathed at tip only, tubercled like the 
stem. 
The species is closely related to Opuntia tunicata but is dis- 
tinguished by its more slender, less spiny stems, and yellow 
instead of glistening silvery white spines. Like that species, 
it produces, at times and under certain conditions, a multi- 
tude of reproductive joints which are comparatively spineless, 
or at least do not have any of the long sheathed spines, and 
are even more easily separable than the terminal spiny ones. 
It is by these latter that theplant ismainlypropagated. Young 
plants produce smaller and less spiny joints, as a rule, and 
the spreading is continued by the repeated breaking off of 
subglobular joints as large as marbles. The two species are 
found, commonly, growing together, or in more or less sep- 
