• Opuntia fuscoatra Engelm.

• Opuntia humifusa (Raf.) Raf.
• Cactus humifusus Raf.
• Opuntia caespitosa Raf.
• Opuntia allairei Griffiths
• Opuntia calcicola Wherry
• Opuntia cespitosa Raf.
• Opuntia cumulicola Small
• Opuntia fuscoatra Engelm.
• Opuntia fusco-atra Engelm.
• Opuntia humifusa var. minor (Engelm.) R.Crook & Mottram
• Opuntia rafinesquei var. minor Engelm.
• Opuntia impedata Small ex Britton & Rose
• Opuntia italica Ten. ex Pfeiff.
• Opuntia mesacantha Raf.
• Opuntia nemoralis Griffiths
• Opuntia rafinesquei Engelm.
• Opuntia vulgaris var. rafinesquii (Engelm.) A.Gray
• Opuntia rubiflora Griffiths

Description: Diffuse prostrate plants; joints orbicular to obovate, somewhat tuberculate, 5 to 8 cm. long,
areoles 12 to 20 mm. apart, very large for the group; spines single or in twos or threes, one rather
stout, sometimes a little flattened, 2.5 to 3 cm. long, yellow to dark brown or even nearly black;
usually from the lower areoles; glochids numerous, brown; flowers 7.5 cm. broad, yellow; petals very
broad; stigma-lobes 5; ovary 2.5 cm. long, slender; fruit 4 to 5 cm. long, red; seeds 4 mm. broad.

Bibliography: THE CACTACEAE (DESCRIPTIONS AND ILLUSTRATIONS OF PLANTS OF THE CACTUS FAMILY)
BY N. L. BRITTON and J. N. ROSE Volume I (The Carnegie Institution of Washington, 1919)