1 Plants lacking joints; areolae lacking glochids (hair-like barbed spines) may be hairy
2 At least some of the areolae bearing hooked spines; immature plants with the spines staying pubescent for a number
of years Sclerocactus
2 Areolae with none of the spines hooked; immature plants not staying pubescent very long or not at all
3 Flowers born laterally below the apex; hypanthium bearing spines; flowers red, red-orange or purple-lavender
Echinocereus
3 Flowers born on the apex of the plant; hypanthium spineless; flowers white to yellow, pale or rose-pink, violet;
plants usually not obviously mound-forming, may be a few plants, but not making large mounds
4 Tubercles generally with a groove on one side; flower and fruit separate from the spine bearing tubercles; flower
reddish Coryphantha
4 Tubercles not grooved on one side; flowers and fruit connected with the spine bearing tubercles, thus appearing
to have a cluster of spines at the base of the flower and fruit; flowers white to yellow, or pale pinkish Pediocactus
1 Plants having joints; areolae having glochids
5 Joints round in cross section and clavate Grusonia
5 Joints flat Opuntia
CORYPHANTHA
Coryphantha vivipara (Nutt.) Britt. & Rose
ARIZONA FOXTAIL CACTUS. Infrequent, below 7000 ft.; on open limestone rocky slopes and flats, gravelly slopes. All varieties have been submersed under the species in Flora of North America 2003. May-June. *Cross Road T13N R70E S5, . [var. arizonica (Engelm.) W. Marshall].
ECHINOCEREUS Hedgehog Cactus
1 Petaloids scarlet or red; mature stems with the vegetative areoles bearing white felt or cobwebby hairs E. triglochidiatus
1 Petaloids purplish to magenta; mature stems with the vegetative areoles lacking white felt or cobwebby hairs (felt of
young areoles persistent 1-2 years E. engelmannii
Echinocereus engelmannii (Parry ex Engelm.) Lam.
NORTHERN SAINTS CACTUS. Infrequent, 5900-5500 ft.: rocky slopes. June. *Hamlin Valley 749 530E 42 90 422N Clifton 45157, between Shingle and Pine Creek 725346E 4318440N Clifton 45670.
Echinocereus triglochidiatus Engelm.
MOJAVE KING CUP CACTUS. Limited, below 6500 ft.; low exposed slabs of limestone. Late April-May. *†between Murphy Wash and Johns Wash 732 287E 42 87 868N Clifton 43961, Snake Creek 753 780E 43 11 636N.
GRUSONIA
Grusonia pulchella (Engelm.) H. Robins.
SAND CHOLLA. Limited, below 6000; sandy or rocky openings in scrub. May-June. *Cross Road T13N R70E S5, †Hamlin Valley 749 490E 42 90 928N Clifton 45155. [Opuntia p. Engelm.].
OPUNTIA Prickly-pear
Opuntia polyacantha Haw. Complex
STARVATION PRICKLYPEAR. Frequent, below 10100 ft.; rocky places in pinyon-juniper, sagebrush and mountain mahogany. There are trends within this group of polymorphic plants, but there are no real geographical boundaries. Some flowers are self pollinated while others outcross. Even the plants within this range are not consentient. Apr-Aug. !Baker Creek T38 58' 35.2" 114 14' 45" Clifton 11443, *Cross Road T13N R70E S5, Decathon Canyon 736 405E 43 01 820N Clifton 45251, Horse Heaven 742 630E 43 14 186N Clifton 45299, Chalk Spring 738190E 435800N (NAD 83). [var. hystricina (Engelm. & Bigel.) Parfitt, var. rufispina (Engelm. & Bigel.) L. Benson].
PEDIOCACTUS
Pediocactus simpsonii (Engelm.) Britt. & Rose
SIMPSON'S FOOTCACTUS. Fairly frequent, below 9500 ft.; openings in sagebrush, on steep slopes and flats. These plants may be a new species as they look different. Apr-May. !Lehman Creek T13N R69E S8.
SCLEROCACTUS Fishhook Cactus
Sclerocactus pubispinus (Engelm.) L. Benson
BASIN FISHHOOK. Widely scattered in the Baker area and on the south end of the range, below 6500 ft.; rocky slopes. These plants only reach 0.6 dm tall and up to about 1 dm wide, they are light colored, thus blending with their habitat. May-Jun. *The Troughs 738 545E 42 79 185N Clifton 43879, †Branch of Weaver Creek 736 272E 43 32 278N Clifton 44006.