Family: Cactaceae
Opuntia
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:
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About 250 species native to the Americas; mostly adapted to fairly dry areas.
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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:
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1. Plants with cylindrical joints |
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2. Spines with sheaths present (subgenus Cylindropuntia) |
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3. Tree-like; joints 8-20 cm long; flowers pink, purple or rose |
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O. imbricata 5. |
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3. Low and bushy; joint to 15 cm long; flowers yellow . O. tunicata 16 |
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2. Spines without sheaths (subgenus Austrocylindropuntia) |
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O. cylindrica 1. |
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5. Joints 3-5 cm long; flowers scarlet; leaves early caducous |
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O. pachypus 9. |
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5. Joints to 60 cm long; flowers red or reddish-yellow to yellowish-green; leaves often persistent |
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O. subulata 14. |
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1. Plants with flattened joints (subgenus Opuntia) |
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6. Areoles without spines |
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8. Habit bushy or tree-like |
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O. ficus-indica 4. |
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O. paraguayensis 10. |
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8. Low and spreading; joints 10-25 cm long |
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O. stricta 13. |
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10. Joints bright-green; fruit globose to subglobose |
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O. microdasys 8. |
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10. Joints greyish-green, velvety; fruit ovoid |
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O. tomentosa 15. |
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11. Plants with an erect cylindrical unjointed trunk |
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12. Flowers c. 7 cm across, yellow with a reddish tinge; fruit red, pear-shaped |
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O. vulgaris 17. |
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12. Flowers c. 5 cm across, orange or red; fruit red or dark-red, ovoid or subovoid |
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O. tomentosa 15. |
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O. elatior 2. |
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11. Plants usually branching near the base, without a definite cylindrical trunk |
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14. Habit erect, often to 7 m high |
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15. Spines yellowish to dark-brown |
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O. vulgaris 17. |
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15. Spines white, with or without a yellowish or brownish base, or absent |
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O. lindheimeri 7. |
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O. robusta 12. |
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17. Spines absent or 1-3 and weak but with numerous bristle-like spines on older parts |
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O. leucotricha 6. |
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O. ficus-indica 4. |
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14. Habit spreading, to 65 cm high |
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19. Joints orbicular to elliptic, to 40 cm long |
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O. phaeacantha 11. |
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19. Joints obovate, 5 to 10 cm long |
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20. Flowers lemon-yellow, greenish outside; fruit fleshy |
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O. stricta 13. |
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20. Flowers white, yellow or red; fruit dry O. erinacea 3 |
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Author:
Not yet available
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