Ivesia santolinoides |
Ivesia paniculata |
|
---|---|---|
mouse tail ivesia, Sierra mousetail, silver mousetail, stellariopsis |
Ash Creek ivesia, Ash Creek mousetail |
|
Habit | Plants ± grayish to silvery. | Plants grayish, ± matted. |
Stems | ascending to erect, (1–)1.5–4 dm. |
± prostrate, 0.4–1.5(–2) dm. |
Basal leaves | mousetail-like (individual leaflets scarcely distinguishable), 3–10 cm; sheathing base densely strigose abaxially; petiole 0.5–1.5 cm; leaflets 60–80 per side, 0.6–1.5 mm, lobes (0–)3–5, obovate to oval, densely villous. |
tightly cylindric, (1.5–)2–5(–7) cm; sheathing base densely hairy abaxially; petiole 0.5–4 cm; lateral leaflets (5–)8–15 per side, overlapping at least distally, ± flabellate, 0.5–2 mm, incised to base or nearly so into (0–)3–8(–15) elliptic to narrowly obovate lobes, apex not or obscurely setose, surfaces densely hirsute, cryptically glandular; terminal leaflets indistinct. |
Cauline leaves | (0–)1; blade reduced. |
|
Inflorescences | (10–)30–200-flowered, 3–8(–30) cm diam. |
20–200-flowered, congested, (1–)1.5–6(–10) cm diam. |
Pedicels | 5–30 mm. |
1.5–6 mm. |
Flowers | 5–8 mm diam.; epicalyx bractlets oblong to broadly ovate or orbiculate, 0.2–0.5 mm; hypanthium 0.5–1.5 × 2–3 mm; sepals 1–2 mm, apex obtuse to acute; petals white, broadly obovate to orbiculate, 2–2.5 mm; stamens 15, filaments 1.2–1.8 mm, anthers purple, broadly obcordate to pouch-shaped, 0.3–0.4 mm; carpels 1, styles 2–3 mm. |
4–6 mm diam.; epicalyx bractlets 5, lanceolate to elliptic, 0.6–1.5(–2) mm; hypanthium shallowly cupulate, 1 × 2–3 mm; sepals (1–)1.5–2.5(–3) mm, acute; petals white to pale yellowish, linear, 1 mm; stamens 5, filaments 0.3–1 mm, anthers yellow with maroon margins, ovate, 0.3–0.5 mm; carpels 1–2(–3), styles 0.7–1.8 mm. |
Achenes | mottled grayish brown, 1.7–2 mm. |
brown, 0.8–1.5 mm, smooth, prominently carunculate. |
2n | = 28. |
|
Ivesia santolinoides |
Ivesia paniculata |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Dry sandy granitic soil, decomposed granite accumulations, ledges and outcrops, in montane and subalpine conifer woodlands | Dry shallow volcanic ash and cinders atop volcanic bedrock, open sagebrush communities, adjacent conifer woodlands |
Elevation | 1500–3600 m (4900–11800 ft) | 1500–1800 m (4900–5900 ft) |
Distribution |
CA
|
CA |
Discussion | Ivesia santolinoides is found on loose granitic substrates in the Sierra Nevada, Transverse Ranges, and San Jacinto Mountains from El Dorado to Riverside counties. The species is easily recognized by its silvery mousetail-like leaves and erect, diffuse inflorescences with small, plumlike flowers. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Ivesia paniculata is known only from the Ash Valley area of Lassen County. The distinctions between I. paniculata and I. rhypara are perhaps on the same scale as variation among disjunct population clusters of I. rhypara, but no taxonomic adjustments are proposed at this time. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 246. | FNA vol. 9, p. 229. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Stellariopsis | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae |
Sibling taxa | ||
Synonyms | Potentilla santolinoides, Stellariopsis santolinoides | |
Name authority | A. Gray: Proc. Amer. Acad. Arts 6: 531. (1865) | T. W. Nelson & J. P. Nelson: Brittonia 33: 165, fig. 1. (1981) |
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