Ivesia muirii |
Ivesia santolinoides |
|
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granite mousetail, Muir's ivesia |
mouse tail ivesia, Sierra mousetail, silver mousetail, stellariopsis |
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Habit | Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy. | Plants ± grayish to silvery. |
Stems | usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm. |
ascending to erect, (1–)1.5–4 dm. |
Basal leaves | very tightly cylindric (mousetail-like, with individual leaflets scarcely distinguishable), 2–5(–10) cm; sheathing base densely strigose abaxially; petiole 0.2–0.8(–1) cm, hairs 0.5–1.5 mm; leaflets 25–40 per side, 0.4–1 mm, densely sericeous, glands obscured, lobes 2–5, obovate or oval to orbiculate, apex not setose. |
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. |
Cauline leaves | (0–)1–2, paired if 2. |
|
Inflorescences | 10–30-flowered, 1–2(–3.5) cm diam.; glomerules usually 1. |
(10–)30–200-flowered, 3–8(–30) cm diam. |
Pedicels | 0.3–2(–3.5) mm. |
5–30 mm. |
Flowers | 5–6 mm diam.; epicalyx bractlets oblong to obovate, 0.5–1 mm; hypanthium shallowly cupulate, 0.5–1(–1.5) × 1.5–2.5 mm; sepals (1–)1.5–2.5 mm, acute; petals yellow, linear to oblanceolate or narrowly oblong, 1–2 mm; stamens 5, filaments 0.3–0.6 mm, anthers yellow, 0.4–0.6 mm; carpels 1–4, styles 0.7–1.2 mm. |
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. |
Achenes | grayish brown, mottled with red, 1.6–2 mm. |
mottled grayish brown, 1.7–2 mm. |
2n | = 28. |
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Ivesia muirii |
Ivesia santolinoides |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra | Dry sandy granitic soil, decomposed granite accumulations, ledges and outcrops, in montane and subalpine conifer woodlands |
Elevation | 2900–4000 m (9500–13100 ft) | 1500–3600 m (4900–11800 ft) |
Distribution |
CA
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CA
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Discussion | Ivesia muirii is known from alpine areas in the Sierra Nevada. It is one of the more distinctive species of the genus, in its silvery mousetail-like leaves and usually tightly capitate inflorescences. Putative hybrids are known with I. lycopodioides (D. D. Keck 1938) and I. pygmaea (Center Basin area of Tulare County). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 9, p. 236. | FNA vol. 9, p. 246. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Stellariopsis |
Sibling taxa | ||
Synonyms | Potentilla muirii | Potentilla santolinoides, Stellariopsis santolinoides |
Name authority | A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873) | A. Gray: Proc. Amer. Acad. Arts 6: 531. (1865) |
Web links |