Chaenactis thompsonii |
Chaenactis evermannii |
|
---|---|---|
Thompson's pincushion |
Evermann's pincushion |
|
Habit | Perennials, 10–30 cm (not or scarcely cespitose, not matted); proximal indument thinning with age, grayish, arachnoid-sericeous to thinly lanuginose. | Perennials, mostly 6–12 cm (cespitose or ± matted); proximal indument thinning with age, grayish, mostly arachnoid-sericeous to thinly lanuginose. |
Stems | mostly 5–15+, ascending to erect. |
mostly 5–20+, ascending to erect. |
Leaves | mostly cauline, 2–5 cm; largest blades ± elliptic, ± plane, 1-pinnately lobed; lobes mostly 2–5 pairs, remote, ± plane. |
basal, 1–5 cm; largest blades broadly ± elliptic, ± plane, 1-pinnately lobed; lobes 2–5 pairs, remote, ± plane. |
Peduncles | ascending to erect, 2–5 cm. |
mostly ascending to erect, 5–10 cm. |
Involucres | ± obconic. |
± obconic. |
Corollas | 7–9 mm. |
5–6.5 mm. |
Phyllaries | longest (10–)12–15 mm; outer closely lanuginose, not stipitate-glandular, apices erect, ± rigid. |
longest 8–12 mm; outer predominantly closely lanuginose, sparsely, if at all, stipitate-glandular, 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. |
5–6.5 mm (eglandular); pappi: longest scales 2.5–4.5 mm (lengths 0.4–0.8 times corollas). |
2n | = 12. |
|
Chaenactis thompsonii |
Chaenactis evermannii |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Rocky or gravelly serpentine slopes, scree, talus, openings in or above conifer forests | Subalpine, usually decomposing granitic sand or gravel slopes, ridges, scree, talus, openings in or above conifer forests |
Elevation | (900–)1200–2200 m ((3000–)3900–7200 ft) | 1200–3000 m (3900–9800 ft) |
Distribution |
WA
|
ID |
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.) |
Chaenactis evermannii is known from mountains of central Idaho. Reports of it from Washington and California/Nevada (P. Stockwell 1940, some as C. nevadensis var. mainsiana) were based on specimens of C. thompsonii and C. alpigena, respectively; all three species are closely related. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 407. | FNA vol. 21, p. 408. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus | Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Chaenactis > sect. Macrocarphus |
Sibling taxa | ||
Synonyms | C. nevadensis var. mainsiana | |
Name authority | Cronquist: in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. 5: 123, fig. [p. 125]. (1955) | Greene: Leafl. Bot. Observ. Crit. 2: 224. (1912) |
Web links |