Ivesia santolinoides |
Ivesia saxosa |
|
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mouse tail ivesia, Sierra mousetail, silver mousetail, stellariopsis |
rock ivesia, rock mousetail |
|
Habit | Plants ± grayish to silvery. | Plants green, ± tufted, often forming hanging clumps, sometimes rosetted. |
Stems | ascending to erect, (1–)1.5–4 dm. |
pendent or prostrate to ascending, 0.4–2.6(–3) 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. |
planar, 2–15 cm; sheathing base not strigose abaxially; petiole 3–9 cm; lateral leaflets (1–)2–4(–7) per side, separate to slightly overlapping, obovate to orbiculate or flabellate, (3–)5–15(–22) mm, incised 1/4–3/4 to base into 5–15 broadly ovate teeth or oblanceolate lobes, sometimes also medially split to base (Kern Plateau), apex not setose, surfaces ± sparsely short-pilose, prominently glandular; terminal leaflets ± distinct. |
Cauline leaves | 1–2(–4); blade well developed. |
|
Inflorescences | (10–)30–200-flowered, 3–8(–30) cm diam. |
(1–)3–30(–60)-flowered, open, (0.5–)2–8 cm diam. |
Pedicels | 5–30 mm. |
(5–)10–30 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. |
6–12 mm diam.; epicalyx bractlets 5, broadly lanceolate to oblong, 1–2.5 mm; hypanthium patelliform, 0.5–1.5 × 2–4(–4.5) mm; sepals 2–4.5 mm, acute; petals yellow, oblanceolate to obovate, (1.5–)2–4 mm; stamens 15–35(–40), filaments 0.3–1 mm, anthers yellow, subrotund, 0.2–0.3(–0.5) mm; carpels (3–)10–20(–40), styles 1–2 mm. |
Achenes | mottled grayish brown, 1.7–2 mm. |
greenish white to light tan, 1–1.8 mm, faintly rugose, ± carunculate. |
2n | = 28. |
|
Ivesia santolinoides |
Ivesia saxosa |
|
Phenology | Flowering summer. | Flowering late spring–summer. |
Habitat | Dry sandy granitic soil, decomposed granite accumulations, ledges and outcrops, in montane and subalpine conifer woodlands | Dry, rocky outcrops of granitic or volcanic origin, usually crevices of more or less vertical protected cliffs or boulders, mainly in oak and conifer woodlands |
Elevation | 1500–3600 m (4900–11800 ft) | 900–3300 m (3000–10800 ft) |
Distribution |
CA
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CA; Mexico (Baja California)
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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.) |
Ivesia saxosa is encountered in the foothills and mountains of southeastern California from the White Mountains and adjacent eastern slopes of the Sierra Nevada of Mono County to the Transverse Ranges (including the Little San Bernardino Mountains) of Kern and San Bernardino counties. Populations on the Kern Plateau tend to have more dissected leaflets and may deserve recognition as a distinct variety. On the Peninsular Ranges, I. saxosa occurs in Riverside and San Diego counties and into northern Baja California, Mexico, as far south as the western slopes of the Sierra Juárez and Sierra San Pedro Mártir. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 246. | FNA vol. 9, p. 223. |
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 | Potentilla saxosa, P. acuminata, P. saxosa subsp. sierrae |
Name authority | A. Gray: Proc. Amer. Acad. Arts 6: 531. (1865) | (Lemmon ex Greene) Ertter: Syst. Bot. 14: 232. (1989) |
Web links |