Tetradymia axillaris |
Tetradymia axillaris var. longispina |
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catclaw horsebrush, cottonthorn, longspine horsebrush |
catclaw horsebrush, longspine horsebrush |
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Habit | Shrubs, 50–150 cm. | |||||
Stems | 1–5+, erect or spreading, spiny, evenly pannose. |
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Leaves | primaries forming straight, ± squarrose spines, 10–50 mm; secondaries filiform to clavate, 2–12(–20) mm, sparsely arachnose or glabrous. |
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Peduncles | 4–15 mm. |
and phyllaries tomentose to pannose, canescent. |
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Involucres | turbinate to campanulate, 7–9 mm. |
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Florets | 5–7; corollas pale yellow, 7.5–9 mm. |
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Phyllaries | 5, ovate. |
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Heads | 1–3 (in axils of spines). |
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Cypselae | 4.5–5.5 mm, densely pilose (hairs 6–14 mm); pappi of ca. 25, subulate to setiform scales 6–7.5 mm. |
hairs 9–14 mm. |
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2n | = 60, 62. |
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Tetradymia axillaris |
Tetradymia axillaris var. longispina |
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Phenology | Flowering spring. | |||||
Habitat | Sandy soils, creosote bush scrub, Joshua tree woodlands, pinyon-juniper woodlands, sagebrush scrub | |||||
Elevation | 600–1800 m (2000–5900 ft) | |||||
Distribution |
CA; NV; UT
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CA; NV; UT |
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Discussion | Varieties 2 (2 in the flora). The two varieties of Tetradymia axillaris are partially sympatric and intergrade in areas of overlap. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 632. | FNA vol. 20, p. 632. | ||||
Parent taxa | Asteraceae > tribe Senecioneae > Tetradymia | Asteraceae > tribe Senecioneae > Tetradymia > Tetradymia axillaris | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | T. spinosa var. longispina, T. longispina | |||||
Name authority | A. Nelson: Bot. Gaz. 37: 277. (1904) | (M. E. Jones) Strother: Brittonia 26: 197. (1974) | ||||
Web links |