Chaenactis stevioides

Hooker & Arnott
Bot. Beechey Voy., 353. 1839.
Common names: Desert or Esteve or broad-flower pincushion
Illustrated
Synonyms: Chaenactis furcata Stockwell Chaenactis gillespiei Stockwell Chaenactis latifolia Stockwell Chaenactis mexicana Stockwell Chaenactis stevioides var. brachypappa (A. Gray) H. M. Hall Chaenactis stevioides var. thornberi Stockwell
Treatment appears in FNA Volume 21. Treatment on page 413. Mentioned on page 409, 411, 414.

Plants 5–30(–45) cm; proximal indument grayish, ± arachnoid-sericeous (tardily glabrescent except around nodes). Stems 1–12 (sometimes decumbent); branches proximal and/or distal. Leaves basal (usually withering) and ± cauline, 1–8(–10) cm; largest blades ± elliptic, ± 3-dimensional, usually not succulent, mostly 1–2-pinnately lobed; primary lobes 4–8 pairs, remote or ± congested, ultimate lobes ± involute and/or twisted. Heads (± radiant) mostly 3–20+ per stem. Peduncles 1–5(–10) cm, usually stipitate-glandular distally and, often, ± arachnoid. Involucres ± hemispheric to obconic (bases green, rounded in fruit). Phyllaries: longest 5.5–8(–10) mm; outer stipitate-glandular and/or ± arachnoid in fruit, apices erect, blunt, ± rigid. Florets: corollas white to pinkish, cream, or pale yellow, 4.5–6.5 mm (inner); peripheral corollas spreading, zygomorphic, enlarged. Cypselae (3–)4–6.5 mm; pappi of (1–)4(–5) scales, usually in 1 series, rarely with partial outer, abruptly unequal series, longest scales 1.5–6 mm, lengths mostly 0.3–0.9 times corollas (apices hidden among corollas at flowering). 2n = 10.


Phenology: Flowering Feb–Jun.
Habitat: Open, arid or semiarid, sandy or gravelly slopes and flats, shrublands
Elevation: -30–2100(–2300) m

Distribution

V21-1037-distribution-map.gif

Ariz., Calif., Colo., Idaho, Nev., N.Mex., Oreg., Utah, Wyo., Mexico (Baja California, Sonora).

Discussion

Chaenactis stevioides is found throughout the southwestern deserts; it is among the most abundant spring wildflowers in the higher Mojave Desert and southern Great Basin. It also extends seaward into west-central California. It has been reported in New York as a garden escape; it is not expected to persist there outside cultivation.

Chaenactis stevioides varies in more or less concentric zones. Plants from the core zone (centered on the Great Basin and Mojave Desert) typically have pappi and phyllaries relatively short and phyllaries predominantly stipitate-glandular (var. brachypappa). Surrounding this zone to the southwest, southeast, and northeast are plants with pappi and phyllaries relatively long and phyllaries evidently or predominantly lanuginose (var. stevioides). Scattered on the periphery in central Arizona, Baja California, and west-central and southwestern California (where hybrids may be involved; see sectional discussion) are mesophytic forms with relatively long and/or broad leaf divisions, corollas varying from white to pale yellow, and pappi and phyllaries like those of var. brachypappa (var. thornberi, C. gillespiei). An unnamed form with leaves arachnoid but otherwise like C. fremontii occurs around sand dunes in the Mojave Desert. Chaenactis furcata and C. latifolia are forms possibly influenced by C. fremontii genes, unusual substrates, or pathogens. Traits of all the above taxa are inconsistent within populations, and/or recurrent or recombinant elsewhere in the range of C. stevioides.

Selected References

None.

Lower Taxa

None.

... more about "Chaenactis stevioides"
James D. Morefield +
Hooker & Arnott +
Desert or Esteve or broad-flower pincushion +
Ariz. +, Calif. +, Colo. +, Idaho +, Nev. +, N.Mex. +, Oreg. +, Utah +, Wyo. +, Mexico (Baja California +  and Sonora). +
-30–2100(–2300) m +
Open, arid or semiarid, sandy or gravelly slopes and flats, shrublands +
Flowering Feb–Jun. +
Bot. Beechey Voy., +
Illustrated +
Chaenactis furcata +, Chaenactis gillespiei +, Chaenactis latifolia +, Chaenactis mexicana +, Chaenactis stevioides var. brachypappa +  and Chaenactis stevioides var. thornberi +
Chaenactis stevioides +
Chaenactis sect. Chaenactis +
species +