Chaenactis douglasii |
Chaenactis glabriuscula |
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chaenactis, Douglas' dusty maidens, Douglas' dustymaiden, hoary chaenactis, hoary false-yarrow, hoary pincushion |
common yellow chaenactis, yellow pincushion |
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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 6–60 cm; proximal indument grayish to whitish, arachnoid to densely lanuginose, or glabrescent. | ||||||||||||||||||||
Stems | 1–25+, erect to spreading. |
mostly 1–5(–12; sometimes ± horizontal); branches proximal and, often, distal. |
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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 (often withering) and cauline, 1–10 cm; largest blades linear or ± elliptic, plane to 3-dimensional, succulent or not, (0–)1–2-pinnately lobed; primary lobes 1–7 pairs, remote to ± congested, ultimate lobes ± plane, involute, twisted, and/or terete. |
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Peduncles | mostly ascending to erect, 1–10 cm. |
1–20(–30) cm, distally stipitate-glandular, ± villous, arachnoid-sericeous, lanuginose, and/or glabrescent. |
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Involucres | obconic to ± hemispheric. |
± hemispheric to obconic or broadly cylindric. |
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Florets | corollas bright to dark yellow, 4–8 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 4.5–10 mm; outer stipitate-glandular, ± villous, arachnoid-sericeous, lanuginose, and/or glabrescent in fruit, apices erect, blunt, ± rigid. |
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Heads | 1–25+ per stem. |
(± radiant) mostly 1–20+ per stem. |
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Cypselae | 5–8 mm (usually sparsely glandular amidst other indument); pappi: longest scales 3–6 mm. |
3–9 mm (± terete); pappi of (1–)4 scales in 1 series, or of (5–)8 scales in 2, abruptly unequal series, longest scales (1–)2–8 mm. |
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2n | = 12. |
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Chaenactis douglasii |
Chaenactis glabriuscula |
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Distribution |
AZ; CA; CO; ID; MT; ND; NM; NV; OR; SD; UT; WA; WY; AB; BC
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CA; nw Mexico
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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.) |
Varieties 5 (5 in the flora). The diverse and intergrading forms here included in Chaenactis glabriuscula have been divided by P. Stockwell (1940) and subsequent workers into as many as four species and ten varieties. Chaenactis glabriuscula is known from the southern two-thirds of the Californian Floristic Province and adjacent desert edges. It has been reported in Massachusetts as a garden escape (variety unspecified); it is not expected to persist there outside cultivation. Complete interfertility among the taxa recognized here as Chaenactis glabriuscula vars. glabriuscula, megacephala, and lanosa was demonstrated by P. Stockwell (1940). Intraspecific crosses involving C. glabriuscula var. orcuttiana were much less successful; C. glabriuscula var. heterocarpha was not tested. As noted by W. J. Hooker and G. A. W. Arnott ([1830–]1841) and D. W. Kyhos (1965), some forms of C. glabriuscula differ from C. stevioides or C. fremontii only in corolla color, which can be lost in older or poorly preserved specimens. (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. 411. | ||||||||||||||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus | Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Chaenactis | ||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||
Synonyms | Hymenopappus douglasii, Macrocarphus douglasii | |||||||||||||||||||||
Name authority | (Hooker) Hooker & Arnott: Bot. Beechey Voy., 354. (1839) | de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 659. (1836) | ||||||||||||||||||||
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