Ivesia muirii |
Ivesia cryptocaulis |
|
---|---|---|
granite mousetail, Muir's ivesia |
Charleston Peak ivesia, Charleston Peak mousetail |
|
Habit | Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy. | Plants green, diffusely matted. |
Stems | usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm. |
prostrate to decumbent, 0.2–0.6(–1) 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. |
tightly cylindric, 1–4(–5) cm; sheathing base mostly not strigose abaxially; petiole 0.3–2 cm, hairs 0.5–1 mm; lateral leaflets 5–10(–12) per side, ± overlapping, ± flabellate, 1–2.5 mm, incised to base or nearly so into 3–5 obovate to oval lobes, apex sometimes ± setose, surfaces loosely long-strigose, sparsely glandular; terminal leaflets indistinct. |
Cauline leaves | (0–)1–2, paired if 2. |
1(–2); blade vestigial. |
Inflorescences | 10–30-flowered, 1–2(–3.5) cm diam.; glomerules usually 1. |
1–10-flowered, ± congested, 0.5–1.5 cm diam. |
Pedicels | 0.3–2(–3.5) mm. |
3–7(–10) 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. |
6–9 mm diam.; epicalyx bractlets 5, lanceolate to narrowly oblong or narrowly ovate, 0.8–1.3 mm; hypanthium shallowly cupulate, ± 1 × 2–3(–4) mm; sepals 1.5–2.3 mm, ± acute; petals yellow, oblanceolate to spatulate, 2–3.2 mm; stamens 5, filaments 0.9–1.2 mm, anthers yellow, oblong, 0.7–0.9 mm; carpels 6–10, styles 1–1.5 mm. |
Achenes | grayish brown, mottled with red, 1.6–2 mm. |
greenish cream to light brown, 1.4–1.8(–2) mm, smooth, not carunculate. |
Ivesia muirii |
Ivesia cryptocaulis |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra | Dry to moist limestone gravel, scree, or talus slopes and outcrops, subalpine conifer woodlands, alpine tundra communities |
Elevation | 2900–4000 m (9500–13100 ft) | 2500–3700 m (8200–12100 ft) |
Distribution |
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 cryptocaulis is known only from timberline and above in the Spring Mountains of Clark County. Plants differ from all others of the genus by having slender, elongate, diffuse caudex branches that ramify through its habitat of gravel, scree, and talus. The species is here provisionally included in sect. Setosae as a diffusely matted relative of I. shockleyi (as also suggested by D. D. Keck 1938); the ecarunculate seeds and relatively straight pedicels may indicate a greater similarity to I. pygmaea in sect. Ivesia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 236. | FNA vol. 9, p. 228. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae |
Sibling taxa | ||
Synonyms | Potentilla muirii | Potentilla cryptocaulis |
Name authority | A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873) | (Clokey) D. D. Keck: Lloydia 1: 130. (1939) |
Web links |