Chaenactis douglasii |
Chaenactis fremontii |
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chaenactis, Douglas' dusty maidens, Douglas' dustymaiden, hoary chaenactis, hoary false-yarrow, hoary pincushion |
desert pincushion, Fremont pincushion, Fremont's pincushion, pincushion flower |
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Habit | Biennials or perennials, (2–)5–50(–60) cm (rarely slightly woody or flowering first year, sometimes cespitose or ± matted); proximal indument thinning with age, grayish, mostly arachnoid-sericeous to thinly lanuginose. | Plants 10–30(–40) cm; proximal indument glabrescent (early ± arachnoid, glabrous by flowering). | ||||
Stems | 1–25+, erect to spreading. |
mostly 1–12; branches mainly proximal. |
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Leaves | basal, or basal (sometimes withering) and ± cauline, (1–)2–12(–15) cm; largest blades ± elliptic or slightly lanceolate to ovate, ± 3-dimensional, usually 2-pinnately lobed; primary lobes (4–)5–9(–12) pairs, ± congested, scarcely imbricate, ultimate lobes ± involute and/or twisted. |
basal (withering) and ± cauline, 1–7(–10) cm; largest blades linear and terete or ± elliptic and plane, ± succulent, 0–1-pinnately lobed; lobes 1–2(–5) pairs, remote, ± terete. |
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Peduncles | mostly ascending to erect, 1–10 cm. |
2–8(–10) cm, distally usually ± stipitate-glandular and, sometimes, ± arachnoid (at least early, often glabrescent by fruit). |
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Involucres | obconic to ± hemispheric. |
± hemispheric to obconic (bases pale and ± truncate in fruit). |
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Florets | corollas white to pinkish, 5–8 mm (inner); peripheral corollas spreading, zygomorphic, enlarged. |
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Corollas | 5–8 mm. |
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Phyllaries | longest 9–15(–17) mm; outer usually stipitate-glandular (sometimes sparsely or obscurely, rarely eglandular) and, often, arachnoid to lanuginose and, sometimes, sparsely villous, apices usually ± squarrose, pliant. |
longest 8–10(–12) mm; outer usually glabrescent in fruit, apices erect, acute, ± rigid. |
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Heads | 1–25+ per stem. |
(± radiant) mostly 1–5 per stem. |
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Cypselae | 5–8 mm (usually sparsely glandular amidst other indument); pappi: longest scales 3–6 mm. |
(3–)6–8 mm; pappi of (1–)4(–5) scales in 1 series, longest scales 6–8.5 mm, lengths 1–1.3 times corollas (apices visible among corollas at flowering). |
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2n | = 10. |
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Chaenactis douglasii |
Chaenactis fremontii |
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Phenology | Flowering Mar–May. | |||||
Habitat | Sandy or gravelly soils, warm deserts, often growing through shrubs | |||||
Elevation | -10–1600 m (-0–5200 ft) | |||||
Distribution |
AZ; CA; CO; ID; MT; ND; NM; NV; OR; SD; UT; WA; WY; AB; BC
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AZ; CA; NV; UT; Mexico (Baja California)
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Discussion | Varieties 2 (2 in the flora). Chaenactis douglasii is widespread and variable (see discussion under var. douglasii). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Chaenactis fremontii is often the most abundant spring wildflower in the lower Mojave and northern Sonoran deserts, where it is reported to be a significant food source for desert tortoises (Gopherus agassizii Cooper). It also extends seaward into the southern San Joaquin Valley area of west-central California, often as hybrids with other taxa (see sectional discussion). The involucre bases described above are characteristic of Chaenactis fremontii and can help separate it from some forms of C. stevioides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 405. | FNA vol. 21, p. 414. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Hymenopappus douglasii, Macrocarphus douglasii | |||||
Name authority | (Hooker) Hooker & Arnott: Bot. Beechey Voy., 354. (1839) | A. Gray: Proc. Amer. Acad. Arts 19: 30. (1883) | ||||
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