FNA: Chaenactis thompsonii vs. Chaenactis santolinoides

	Chaenactis thompsonii	Chaenactis santolinoides
	Thompson's pincushion	santolina chaenactis, santolina pincushion
Habit	Perennials, 10–30 cm (not or scarcely cespitose, not matted); proximal indument thinning with age, grayish, arachnoid-sericeous to thinly lanuginose.	Perennials, 10–25(–35) cm (cespitose or ± matted); proximal indument thinning with age, whitish to grayish, lanuginose.
Stems	mostly 5–15+, ascending to erect.	mostly 5–15+, erect to ± spreading.
Leaves	mostly cauline, 2–5 cm; largest blades ± elliptic, ± plane, 1-pinnately lobed; lobes mostly 2–5 pairs, remote, ± plane.	basal, (1–)3–11 cm; largest blades linear-cylindric to ± fusiform, 3-dimensional, 1–2-pinnately lobed; primary lobes (7–)10–18+ pairs, ± imbricate, ultimate lobes ± involute, twisted.
Peduncles	ascending to erect, 2–5 cm.	mostly ascending to erect, mostly 8–25 cm.
Involucres	± obconic.	obconic to ± cylindric.
Corollas	7–9 mm.	5–7 mm.
Phyllaries	longest (10–)12–15 mm; outer closely lanuginose, not stipitate-glandular, apices erect, ± rigid.	longest 8–13 mm; outer evidently stipitate-glandular and, sometimes, ± arachnoid, apices erect, ± rigid.
Heads	mostly 1–3 per stem.	1(–3) per stem.
Cypselae	7–9 mm (eglandular); pappi: longest scales 3.5–5 mm.	4–6 mm; pappi: longest scales 3–4.5 mm.
2n		= 12.

	Chaenactis thompsonii	Chaenactis santolinoides
Phenology	Flowering Jun–Aug.	Flowering (Mar–)May–Jul.
Habitat	Rocky or gravelly serpentine slopes, scree, talus, openings in or above conifer forests	Exposed sandy to rocky summits, ridges, scree, talus, openings in or above conifer forests, sometimes road cuts or other recent disturbances
Elevation	(900–)1200–2200 m [(3000–)3900–7200 ft]	(1100–)1500–2800 m [(3600–)4900–9200 ft]
Distribution	WA [WildflowerSearch map] [BONAP county map]	CA [WildflowerSearch map] [BONAP county map]
Discussion	Of conservation concern. Chaenactis thompsonii appears to be sister to C. evermannii; it is known from the mountains of central and northwestern Washington. The similar habits of C. thompsonii and C. ramosa (= C. douglasii var. douglasii) appear to result from convergent evolution in the distinctive habitat of their type localities (Wenatchee Mountains), not from a close genetic relationship as suggested by Cronquist. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Of conservation concern. Chaenactis santolinoides is known from the southern Sierra Nevada and Transverse Ranges. It is sometimes cultivated in rock gardens and may be found beyond its native range. It may be relatively recently derived from an isolated segment of C. douglasii var. alpina. The morphology of C. panamintensis (here assigned to C. douglasii var. alpina) suggests past convergence toward, or genetic influence from, C. santolinoides. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Parent taxa	Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus	Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus
Sibling taxa	C. alpigena, C. artemisiifolia, C. carphoclinia, C. cusickii, C. douglasii, C. evermannii, C. fremontii, C. glabriuscula, C. macrantha, C. nevadensis, C. nevii, C. parishii, C. santolinoides, C. stevioides, C. suffrutescens, C. xantiana	C. alpigena, C. artemisiifolia, C. carphoclinia, C. cusickii, C. douglasii, C. evermannii, C. fremontii, C. glabriuscula, C. macrantha, C. nevadensis, C. nevii, C. parishii, C. stevioides, C. suffrutescens, C. thompsonii, C. xantiana
Name authority	Cronquist: in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. 5: 123, fig. [p. 125]. (1955)	Greene: Bull. Torrey Bot. Club 9: 17. (1882)
Source	FNA vol. 21, p. 407. Treatment author: James D. Morefield.	FNA vol. 21, p. 407. Treatment author: James D. Morefield.
Web links	Local floras: WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Chaenactis santolinoides

Thompson's pincushion

santolina chaenactis, santolina pincushion

Habit

Perennials, 10–30 cm (not or scarcely cespitose, not matted); proximal indument thinning with age, grayish, arachnoid-sericeous to thinly lanuginose.

Perennials, 10–25(–35) cm (cespitose or ± matted); proximal indument thinning with age, whitish to grayish, lanuginose.

Stems

mostly 5–15+, ascending to erect.

mostly 5–15+, erect to ± spreading.

Leaves

mostly cauline, 2–5 cm;

largest blades ± elliptic, ± plane, 1-pinnately lobed;

lobes mostly 2–5 pairs, remote, ± plane.

basal, (1–)3–11 cm;

largest blades linear-cylindric to ± fusiform, 3-dimensional, 1–2-pinnately lobed;

primary lobes (7–)10–18+ pairs, ± imbricate, ultimate lobes ± involute, twisted.

Peduncles

ascending to erect, 2–5 cm.

mostly ascending to erect, mostly 8–25 cm.

Involucres

± obconic.

obconic to ± cylindric.

Corollas

7–9 mm.

5–7 mm.

Phyllaries

longest (10–)12–15 mm;

outer closely lanuginose, not stipitate-glandular, apices erect, ± rigid.

longest 8–13 mm;

outer evidently stipitate-glandular and, sometimes, ± arachnoid, apices erect, ± rigid.

Heads

mostly 1–3 per stem.

1(–3) per stem.

Cypselae

7–9 mm (eglandular);

pappi: longest scales 3.5–5 mm.

4–6 mm;

pappi: longest scales 3–4.5 mm.

= 12.

Chaenactis santolinoides

Phenology

Flowering Jun–Aug.

Flowering (Mar–)May–Jul.

Habitat

Rocky or gravelly serpentine slopes, scree, talus, openings in or above conifer forests

Exposed sandy to rocky summits, ridges, scree, talus, openings in or above conifer forests, sometimes road cuts or other recent disturbances

Elevation

(900–)1200–2200 m [(3000–)3900–7200 ft]

(1100–)1500–2800 m [(3600–)4900–9200 ft]

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Of conservation concern.

Chaenactis thompsonii appears to be sister to C. evermannii; it is known from the mountains of central and northwestern Washington. The similar habits of C. thompsonii and C. ramosa (= C. douglasii var. douglasii) appear to result from convergent evolution in the distinctive habitat of their type localities (Wenatchee Mountains), not from a close genetic relationship as suggested by Cronquist.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Of conservation concern.

Chaenactis santolinoides is known from the southern Sierra Nevada and Transverse Ranges. It is sometimes cultivated in rock gardens and may be found beyond its native range. It may be relatively recently derived from an isolated segment of C. douglasii var. alpina. The morphology of C. panamintensis (here assigned to C. douglasii var. alpina) suggests past convergence toward, or genetic influence from, C. santolinoides.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Parent taxa

Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus

Sibling taxa

C. alpigena, C. artemisiifolia, C. carphoclinia, C. cusickii, C. douglasii, C. evermannii, C. fremontii, C. glabriuscula, C. macrantha, C. nevadensis, C. nevii, C. parishii, C. santolinoides, C. stevioides, C. suffrutescens, C. xantiana

C. alpigena, C. artemisiifolia, C. carphoclinia, C. cusickii, C. douglasii, C. evermannii, C. fremontii, C. glabriuscula, C. macrantha, C. nevadensis, C. nevii, C. parishii, C. stevioides, C. suffrutescens, C. thompsonii, C. xantiana

Name authority

Cronquist: in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. 5: 123, fig. [p. 125]. (1955)

Greene: Bull. Torrey Bot. Club 9: 17. (1882)

Source

FNA vol. 21, p. 407. Treatment author: James D. Morefield.

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

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Flora of North America species comparison

Chaenactis thompsonii

Chaenactis santolinoides

Chaenactis thompsonii

Chaenactis santolinoides