Chaenactis artemisiifolia |
Chaenactis xantiana |
|
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artemisia leaf chaenactis, white pincushion |
fleshcolor pincushion, fleshy pincushion, Xantus pincushion, Xantus' chaenactis |
|
Habit | Plants (15–)25–90(–200) cm. | Plants 10–40 cm; proximal indument grayish, sparsely arachnoid, early glabrescent (usually glabrous by flowering). |
Stems | mostly 1–5(–12); branches proximal and/or distal. |
|
Leaves | basal (withering) and cauline, 3–15(–20) cm; largest blades ± plane, not succulent; primary lobes mostly 5–10 pairs, ultimate lobes ± crowded, antrorse, lanceolate to elliptic, plane. |
basal (withering) and cauline, (1–)2–6 cm; largest blades linear or ± elliptic, ± plane or terete, ± succulent, 0–1-pinnately lobed; lobes 1–2(–5) pairs, remote, ± terete. |
Peduncles | 1.5–6 cm. |
1–5(–8) cm, glabrous (and ± expanded) distally. |
Involucres | ± hemispheric, mostly 10–15 mm diam. |
broadly obconic to campanulate. |
Receptacles | paleae 0. |
|
Florets | corollas (diurnal) dirty-whitish to pinkish, 6–10 mm (± equal to cypsela lengths, anthers exserted); peripheral corollas erect to ascending, actinomorphic, scarcely enlarged. |
|
Corollas | 5–7 mm. |
|
Phyllaries | longest 7–10(–12) mm, ± densely villous, not or sparsely glandular; apices (all) erect, ± green, acute or scarcely acuminate, not aristate, ± plane. |
longest 10–18 mm (surpassed by florets); outer distally tomentulose-puberulent in fruit (proximally glabrous, not stipitate-glandular), apices ± squarrose, blunt, pliant. |
Heads | mostly 1–5(–7) per stem. |
|
Cypselae | compressed, 4–7 mm; pappi 0 or coroniform (of ± 10 scales, longest 0.1–0.5 mm). |
5–9 mm; pappi of 8 scales in 2, abruptly unequal series, longest scales 5–9 mm. |
2n | = 16. |
= 14. |
Chaenactis artemisiifolia |
Chaenactis xantiana |
|
Phenology | Flowering Apr–early Jul. | Flowering late Mar–Jul. |
Habitat | Dry canyons, open slopes, often over granitoid rocks, locally abundant in chaparral burns or other recovering disturbances | Open, deep, loose sandy (rarely gravelly) soils, arid and semiarid shrublands, chaparral |
Elevation | 80–1600 m (300–5200 ft) | (100–)300–2500 m ((300–)1000–8200 ft) |
Distribution |
CA; Mexico (Baja California)
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AZ; CA; NV; OR
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Discussion | In the flora area, Chaenactis artemisiifolia is known from the Transverse and Peninsular ranges and seaward valleys of southwestern California. It is fire-adapted; its germination is significantly enhanced by exposure to biomass smoke (J. E. Keeley and C. J. Fotheringham 1998). Chaenactis lacera Greene, the eighteenth species of the genus, is known from coastal portions (including islands) of the western Vizcaíno Desert in Baja California and Baja California Sur, Mexico. Forms of C. artemisiifolia sometimes resemble C. lacera in coastal southern California (P. Stockwell 1940), where C. lacera could eventually be introduced. Besides the key characteristics above, C. lacera differs from C. artemisiifolia by its largest leaf blades broadly ± elliptic, 2–3-pinnately lobed, ultimate lobes remote, recurved to retrorse, ± linear, involute (leaf blades appearing ± skeletal). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 21, p. 402. | FNA vol. 21, p. 410. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Acarphaea artemisiifolia | |
Name authority | (Harvey & A. Gray) A. Gray: Proc. Amer. Acad. Arts 10: 74. (1874) | A. Gray: Proc. Amer. Acad. Arts 6: 545. (1865) |
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