Contains 6 accepted taxa overall.
Characteristics
Classification
Citation
OPUNTIA Miller, Gard. Dict. Abr., ed. 4. 1754.
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TYPE: Opuntia vulgaris Miller (Cactus opuntia Linnaeus) Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 2: 571. 1913.
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Opuntia drummondii | Dune Prickly-pear, Sand-bur Prickly-pear, Little Prickly-pear, Creeping Cactus | |||
| Opuntia lindheimeri | Texas Prickly-pear | |||
| Opuntia mesacantha ssp. lata | Prickly-pear | |||
| Opuntia mesacantha ssp. mesacantha | Prickly-pear | |||
| Opuntia stricta var. dillenii | Coastal Prickly Pear, Shell Midden Prickly- pear, Yaaxpakan | |||
| Opuntia stricta var. stricta | Coastal Prickly Pear, Shell Midden Prickly-pear |
Identification Key
1. Spines absent; inner petaloid tepals red and appressed; stamens and style much exserted beyond the tepals
1. Spines present or absent; inner petaloid tepals yellow (rarely reddish) and spreading; stamens and style not exserted beyond the tepals
2
2. Surface of cladodes (stem segments) pubescent
2. Surface of cladodes (stem segments) glabrous
3
3. Mature cladodes 10-60 cm long, usually with >15 areoels per face (not counting areoles along the margin), often without spines, glochids conspicuous or inconspicuous
4
3. Mature cladodes mostly 8-25 cm long, with <15 areoles per face (not counting areoles along the margin), with or without spines, usually with conspicuous glochids to 4 mm long
5
4. Mature cladodes mostly (25)30-60 cm long, with inconspicuous glochids to 2 mm long
4. Mature cladodes mostly 10-20 cm long, replete with conspicous tufts of glochids
5. Distal cladodes with 1-2 areoles per diagonal row per face, narrowly ovate, elliptic, to linear, mostly 1-2.5 cm wide, subcylindric to slightly flattened, loosely attached and readily disarticulating; spines strongly barbed apically
5. Distal cladodes with 2-4 areoles per diagonal row per face, obovate to elliptic, mostly 2.5-16 cm wide, flattened, firmly attached ro readily disarticulating; spines barbed apically or not
6
6. Spines disposed from areoles in a stellate pattern or in different planes, ascending to spreading or recurved; radial spines numerous or absent; young spines yellow to dark yellow
7
6. Spines disposed from areoles mostly in the same plane and perpendicular to the stem; radial spines 0-1; young spines red, brown, whitish, or dark yellow
9
6. Mature spines gray (young spines yellow to dark yellow); stem segments entire to slightly undulate
6. Mature spines yellow to dark yellow; stem segments often with a scalloped or undulate margin
7
7. Tepals pale pinkish orange or peach-colored
7. Tepals yellow
8
8. Cladode margins undulate-tuberculate; areoles usually with abundant, robust spines; spines often strongly flattened at base
8. Cladode margins subentire to lightly undulate; areoles usually with few, short spines; spines often round to slightly flattened at base
9. Mature spines brownish or reddish, often banded
9. Mature spines generally uniformly gray
10
10. Plants forming clumps; cladodes 3.2-13.5 cm long, 2.4-6.7 cm wide, and 6.5-15.8 mm thick, easily disarticulating; caducous leaves 3.5-7.0 mm long; spines strongly retrorsely barbed to the touch; fruits 2.1-3.0 cm long; seeds 3.1-3.6 mm long
10. Plants forming mats, clumps, or erect shrubs; cladodes 3.1-24(29.5) cm long, 2-9.5 cm wide, and 3.6-19.9 mm thick, usually not easily disarticulating (sometimes easily disarticulating in summer months in O. mesacantha); caducous leaves 4.8-13.8 mm long; spines strongly barbed or not; fruits 2.1-5.0 cm long; seeds 3.9-5.7 mm long
11
11. Erect shrubs (developing a definite erect trunk), 0.3–2 m tall, with thick tuberous rootstock, the stems strongly ascending or erect; cladodes obovate to elliptic, rarely completely round, often relatively strongly narrowed and acute at the base, sometimes slightly glaucous, never cross wrinkling unless under severe drought stress, 6.5–29.5 cm long, 3.7–9.5 cm wide, 6.4–10.9 mm thick; pericarpel often <2 times as long as wide (when fresh); seeds 3.9–4.7 mm long
11. Small shrubs in clumps or mats (trunk not evident or poorly formed), 0.1–0.5 m tall, roots mostly cord-like or fibrous, the stems weakly ascending, decumbent or trailing; cladodes mostly obovate, rotund, or elliptic, often relatively broadly rounded at the base, not glaucous, often cross-wrinkling during the winter, 3.1–17.7 long, 2-9 cm wide, 3.6–19.9 mm thick; pericarpel often >2 times as long as wide (when fresh); seeds 4.7–5.9 mm long
12
12. Cladodes typically scalloped-margined, elliptical or rotund; spines delicate, 0.7–0.9 mm in diameter; seeds with the funicular envelope smooth, only moderate, if any, protrusion of the cotyledons and hypocotyl
12. Cladodes typically smooth-margined, obovate or rotund; spines robust, 0.95–1.3 mm in diameter; seeds with the funicular envelope bumby, cotyledons and hypocotyl noticeably protruding
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| No synonyms found. | |||