[Illustration: Opuntia spinosior
Opuntia fulgida
Opuntia acanthocarpa]
Common names: CHOLLA, CANE CACTUS, WALKINGSTICK CHOLLA, BUCKHORN
CHOLLA
Arizona desert: (_Opuntia spinosior_). Red-purple. May-June.
California desert: (_Opuntia acanthocarpa_). Yellow-purple. April-May.
Texas desert: (_Opuntia imbricata_). Red-purple. May-June.
Cactus family. Size: Shrubby, from 3 to 8 feet high.
Aside from the true Tree Cholla (_Opuntia fulgida_), which is the
largest of the branching, cylindrical-jointed cacti and is very common
in restricted portions of the desert in the Tucson-Phoenix area, the
species listed above are the largest, most representative, and most
widely spread of the Chollas (CHOH-yahs).
The bright red to purple flowers of _O. spinosior_ and _O. imbricata_
make them particularly attractive during the blossoming season, while
the extreme variability, from yellow to red and purple, of the flowers
of _O. acanthocarpa_ make its identification by this means always a
matter of uncertainty. Fruits of _spinosior_ and _imbricata_ are quite
large, yellow, and at a distance may be mistaken for blossoms.
Flowers of _O. fulgida_ are small, pink, and appear in midsummer
followed by fruits which remain on the plant to form long hanging
clusters relished by cattle. A hybrid between _spinosior_ and _fulgida_
is reported along the Gila River west of Florence, Arizona.