Ivesia muirii |
Ivesia jaegeri |
|
---|---|---|
granite mousetail, Muir's ivesia |
Jaeger's ivesia, Jaeger's mousetail |
|
Habit | Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy. | Plants green, ± tufted to ± matted, often forming hanging clumps, sometimes rosetted. |
Stems | usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm. |
pendent or prostrate to ascending, 0.3–1.5 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. |
± loosely cylindric to weakly planar, 2–8(–10) cm; sheathing base not or sparsely strigose abaxially; petiole 0.5–4 cm; lateral leaflets (1–)4–6(–8) per side, ± overlapping at least distally, ± flabellate, 2–6(–7) mm, incised nearly to base into 3–6 oblanceolate to narrowly obovate lobes, apex not or scarcely setose, surfaces ± sparsely short-pilose, ± glandular; terminal leaflets indistinct. |
Cauline leaves | (0–)1–2, paired if 2. |
(1–)2; blade well developed. |
Inflorescences | 10–30-flowered, 1–2(–3.5) cm diam.; glomerules usually 1. |
(1–)3–15-flowered, open, (0.5–)1.5–4(–7) 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. |
5–11 mm diam.; epicalyx bractlets 5, lanceolate, 1–2 mm; hypanthium patelliform, 1 × 2–4 mm; sepals 2–3 mm, ± acute; petals yellow, narrowly oblanceolate, 1.5–2 mm; stamens 20, filaments 1–1.5(–1.8) mm, anthers yellow, subrotund, 0.2–0.3 mm; carpels 3–8, styles 1.5–2 mm. |
Achenes | grayish brown, mottled with red, 1.6–2 mm. |
tan to light brown, 1–2 mm, ± rugose, ± carunculate. |
Ivesia muirii |
Ivesia jaegeri |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra | Dry, rocky outcrops of limestone origin, usually crevices of more or less vertical protected cliffs or boulders, mainly in conifer woodlands |
Elevation | 2900–4000 m (9500–13100 ft) | 1600–3600 m (5200–11800 ft) |
Distribution |
CA
|
CA; NV |
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.) |
Of conservation concern. Ivesia jaegeri is known only from the Spring Mountains, Clark County, Nevada, and the Clark Mountains, San Bernardino County, California. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 236. | FNA vol. 9, p. 223. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae |
Sibling taxa | ||
Synonyms | Potentilla muirii | Potentilla jaegeri |
Name authority | A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873) | Munz & I. M. Johnston: Bull. Torrey Bot. Club 56: 165. (1929) |
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