The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

chaenactis, Douglas' dusty maidens, Douglas' dustymaiden, hoary chaenactis, hoary false-yarrow, hoary pincushion

common yellow chaenactis, yellow pincushion

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.

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.

Peduncles

mostly ascending to erect, 1–10 cm.

1–20(–30) cm, distally stipitate-glandular, ± villous, arachnoid-sericeous, lanuginose, and/or glabrescent.

Involucres

obconic to ± hemispheric.

± hemispheric to obconic or broadly cylindric.

Florets

corollas bright to dark yellow, 4–8 mm (inner);

peripheral corollas spreading, ± zygomorphic, enlarged.

Corollas

5–8 mm.

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.

Heads

1–25+ per stem.

(± radiant) mostly 1–20+ per stem.

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.

2n

= 12.

Chaenactis douglasii

Chaenactis glabriuscula

Distribution
from FNA
AZ; CA; CO; ID; MT; ND; NM; NV; OR; SD; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; nw Mexico
[WildflowerSearch map]
[BONAP county map]
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.)

Key
1. Leaves basal (sometimes withering) and ± cauline; plants not or scarcely cespitose, not matted; stems usually 1–5(–12); heads (1–)2–25+ per stem
var. douglasii
1. Leaves strictly basal; plants cespitose or ± matted; stems (1–)10–25+; heads 1(–2) per stem
var. alpina
1. Pappi of (5–)8 scales in 2, abruptly unequal series
var. heterocarpha
1. Pappi of (1–)4(–5) scales in 1 series
→ 2
2. Proximal indument whitish, ± densely lanuginose; leaves ± basal (persistent)
var. lanosa
2. Proximal indument grayish, ± arachnoid, or glabrescent; leaves basal (withering) and cauline
→ 3
3. Largest leaf blades succulent, mostly 2-pinnately lobed; stems ± horizontal
var. orcuttiana
3. Largest leaf blades scarcely succulent, 1(–2)-pinnately lobed; stems ascending to erect
→ 4
4. Longest phyllaries 7–9 × 2–3 mm, outer glabrescent in fruit; pappi: lengths of longest scales ± 0.9(–1) times corollas
var. megacephala
4. Longest phyllaries 5–7 × 1–2 mm, outer (at least medially) ± arachnoid-sericeous and, often, ± stipitate-glandular in fruit; pappi: lengths of longest scales 0.4–0.7 times corollas
var. glabriuscula
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
C. alpigena, C. artemisiifolia, C. carphoclinia, C. cusickii, C. evermannii, C. fremontii, C. glabriuscula, C. macrantha, C. nevadensis, C. nevii, C. parishii, C. santolinoides, C. stevioides, C. suffrutescens, C. thompsonii, C. xantiana
C. alpigena, C. artemisiifolia, C. carphoclinia, C. cusickii, C. douglasii, C. evermannii, C. fremontii, C. macrantha, C. nevadensis, C. nevii, C. parishii, C. santolinoides, C. stevioides, C. suffrutescens, C. thompsonii, C. xantiana
Subordinate taxa
C. douglasii var. alpina, C. douglasii var. douglasii
C. glabriuscula var. glabriuscula, C. glabriuscula var. heterocarpha, C. glabriuscula var. lanosa, C. glabriuscula var. megacephala, C. glabriuscula var. orcuttiana
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)
Web links