FNA: Chaenactis artemisiifolia vs. Chaenactis santolinoides

	Chaenactis artemisiifolia	Chaenactis santolinoides
	artemisia leaf chaenactis, white pincushion	santolina chaenactis, santolina pincushion
Habit	Plants (15–)25–90(–200) cm.	Perennials, 10–25(–35) cm (cespitose or ± matted); proximal indument thinning with age, whitish to grayish, lanuginose.
Stems		mostly 5–15+, erect to ± spreading.
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, (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	1.5–6 cm.	mostly ascending to erect, mostly 8–25 cm.
Involucres	± hemispheric, mostly 10–15 mm diam.	obconic to ± cylindric.
Receptacles	paleae 0.
Corollas	5–7 mm.	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 8–13 mm; outer evidently stipitate-glandular and, sometimes, ± arachnoid, apices erect, ± rigid.
Heads		1(–3) per stem.
Cypselae	compressed, 4–7 mm; pappi 0 or coroniform (of ± 10 scales, longest 0.1–0.5 mm).	4–6 mm; pappi: longest scales 3–4.5 mm.
2n	= 16.	= 12.

	Chaenactis artemisiifolia	Chaenactis santolinoides
Phenology	Flowering Apr–early Jul.	Flowering (Mar–)May–Jul.
Habitat	Dry canyons, open slopes, often over granitoid rocks, locally abundant in chaparral burns or other recovering disturbances	Exposed sandy to rocky summits, ridges, scree, talus, openings in or above conifer forests, sometimes road cuts or other recent disturbances
Elevation	80–1600 m (300–5200 ft)	(1100–)1500–2800 m ((3600–)4900–9200 ft)
Distribution	CA; Mexico (Baja California) [WildflowerSearch map] [BONAP county map]	CA [WildflowerSearch map] [BONAP county map]
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.)	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.)
Source	FNA vol. 21, p. 402.	FNA vol. 21, p. 407.
Parent taxa	Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Acarphaea	Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus
Sibling taxa	C. alpigena, 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. thompsonii, 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
Synonyms	Acarphaea artemisiifolia
Name authority	(Harvey & A. Gray) A. Gray: Proc. Amer. Acad. Arts 10: 74. (1874)	Greene: Bull. Torrey Bot. Club 9: 17. (1882)
Web links	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	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

artemisia leaf chaenactis, white pincushion

santolina chaenactis, santolina pincushion

Habit

Plants (15–)25–90(–200) cm.

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

Stems

mostly 5–15+, erect to ± spreading.

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, (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

1.5–6 cm.

mostly ascending to erect, mostly 8–25 cm.

Involucres

± hemispheric, mostly 10–15 mm diam.

obconic to ± cylindric.

Receptacles

paleae 0.

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 8–13 mm;

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

Heads

1(–3) per stem.

Cypselae

compressed, 4–7 mm;

pappi 0 or coroniform (of ± 10 scales, longest 0.1–0.5 mm).

4–6 mm;

pappi: longest scales 3–4.5 mm.

= 16.

= 12.

Chaenactis santolinoides

Phenology

Flowering Apr–early Jul.

Flowering (Mar–)May–Jul.

Habitat

Dry canyons, open slopes, often over granitoid rocks, locally abundant in chaparral burns or other recovering disturbances

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

Elevation

80–1600 m (300–5200 ft)

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

Distribution

CA; Mexico (Baja California)

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

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.)

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.)

Source

FNA vol. 21, p. 402.

FNA vol. 21, p. 407.

Parent taxa

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

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

Sibling taxa

C. alpigena, 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. thompsonii, 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

Synonyms

Acarphaea artemisiifolia

Name authority

(Harvey & A. Gray) A. Gray: Proc. Amer. Acad. Arts 10: 74. (1874)

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

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).

Choose a data source: Flora of North America

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Chaenactis artemisiifolia

Chaenactis santolinoides

Chaenactis artemisiifolia

Chaenactis santolinoides