Citation: Miller, Gard. Dict. edn 4 (1754).

Derivation: Name of some unknown plant mentioned by Pliny.

Synonymy: Not Applicable

Common name: Prickly-Pears.

Description:
Large shrubby or tree-like or low prostrate plants; joints (stems) flattened or terete; leaves mostly small and generally deciduous; spines usually present but sometimes caducous, accompanied by tufts of barbed bristles (glochids) and hairs.

Flowers with a very short tube, mostly borne on the margins of the joints.

Distribution:  About 250 species native to the Americas; mostly adapted to fairly dry areas.

Biology: No text

Taxonomic notes: For the purposes of this flora all plants found in S. Aust. have been treated on the broad basis according to L. Benson (1982) The cacti of the United States and Canada rather than the segregated genera of Backeberg (1958) Die Cactaceae. However, these segregations have been used as subgenera.

Key to Species:

1. Plants with cylindrical joints
2. Spines with sheaths present (subgenus Cylindropuntia)
3. Tree-like; joints 8-20 cm long; flowers pink, purple or rose	O. imbricata 5.
3. Low and bushy; joint to 15 cm long; flowers yellow . O. tunicata 16
2. Spines without sheaths (subgenus Austrocylindropuntia)
4. Joints indistinct	O. cylindrica 1.
4. Joints distinct
5. Joints 3-5 cm long; flowers scarlet; leaves early caducous	O. pachypus 9.
5. Joints to 60 cm long; flowers red or reddish-yellow to yellowish-green; leaves often persistent	O. subulata 14.
1. Plants with flattened joints (subgenus Opuntia)
6. Areoles without spines
7. Joints glabrous
8. Habit bushy or tree-like
9. Joints 30-50 cm long	O. ficus-indica 4.
9. Joints to 21 cm long	O. paraguayensis 10.
8. Low and spreading; joints 10-25 cm long	O. stricta 13.
7. Joints pubescent
10. Joints bright-green; fruit globose to subglobose	O. microdasys 8.
10. Joints greyish-green, velvety; fruit ovoid	O. tomentosa 15.
6. Areoles with spines
11. Plants with an erect cylindrical unjointed trunk
12. Flowers c. 7 cm across, yellow with a reddish tinge; fruit red, pear-shaped	O. vulgaris 17.
12. Flowers c. 5 cm across, orange or red; fruit red or dark-red, ovoid or subovoid
13. Flowers orange	O. tomentosa 15.
13. Flowers red	O. elatior 2.
11. Plants usually branching near the base, without a definite cylindrical trunk
14. Habit erect, often to 7 m high
15. Spines yellowish to dark-brown	O. vulgaris 17.
15. Spines white, with or without a yellowish or brownish base, or absent
16. Fruits purple	O. lindheimeri 7.
16. Fruits red or white
17. Spines 8-12, stout	O. robusta 12.
17. Spines absent or 1-3 and weak but with numerous bristle-like spines on older parts
18. Joints 10-25 cm long	O. leucotricha 6.
18. Joints 30-50 cm long	O. ficus-indica 4.
14. Habit spreading, to 65 cm high
19. Joints orbicular to elliptic, to 40 cm long	O. phaeacantha 11.
19. Joints obovate, 5 to 10 cm long
20. Flowers lemon-yellow, greenish outside; fruit fleshy	O. stricta 13.
20. Flowers white, yellow or red; fruit dry O. erinacea 3

Author: Not yet available