Ivesia muirii |
Ivesia setosa |
|
---|---|---|
granite mousetail, Muir's ivesia |
bristly ivesia |
|
Habit | Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy. | Plants green, tufted to ± densely matted. |
Stems | usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm. |
± ascending to nearly erect, 0.7–2.5(–2.8) 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. |
weakly planar to loosely cylindric, 5–9(–12) cm; sheathing base ± strigose abaxially; petiole 1–8 cm; lateral leaflets 5–10 per side, separate to overlapping distally, ± flabellate, 2–8 mm, incised ± 3/4 to base, sometimes nearly to base, into (3–)7–11 ovate teeth to narrowly obovate lobes, apex usually ± setose, surfaces ± sparsely hirsute, conspicuously glandular; terminal leaflets ± indistinct. |
Cauline leaves | (0–)1–2, paired if 2. |
(0–)1; blade vestigial. |
Inflorescences | 10–30-flowered, 1–2(–3.5) cm diam.; glomerules usually 1. |
(1–)5–15(–30)-flowered, ± open, 1–6(–12) cm diam. |
Pedicels | 0.3–2(–3.5) mm. |
5–15(–20) 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. |
7–10 mm diam.; epicalyx bractlets 5, lanceolate, 1.3–2.5(–3) mm; hypanthium patelliform, (1–)1.5–2 × 2–3.5(–4) mm; sepals (1.5–)2–3.5 mm, ± acute; petals yellow, oblanceolate to narrowly spatulate, 1.5–2.5 mm; stamens 5, filaments 0.8–1.5 mm, anthers yellow, oblong, 0.4–0.7 mm; carpels 2–8, styles 1.2–2 mm. |
Achenes | grayish brown, mottled with red, 1.6–2 mm. |
greenish white to light tan, 1.7–2 mm, smooth, ± carunculate. |
Ivesia muirii |
Ivesia setosa |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra | Dry, rocky talus slopes, boulders and outcrops, most often but not always of calcareous origin, occasionally away from immediate outcrops, sagebrush communities, conifer woodlands |
Elevation | 2900–4000 m (9500–13100 ft) | 1800–2600(–3100) m (5900–8500(–10200) ft) |
Distribution |
CA
|
NV; UT |
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 setosa occurs mostly to the east and south of I. baileyi, from southeastern Humboldt and Churchill counties to Elko, White Pine, and northern Nye counties, Nevada, and in the Deep Creek Range of western Utah. It represents a transition between the planar-leaved, chasmophytic members of sect. Setosae and the cylindric-leaved, matted species of flatter sites. Stems of I. setosa are more generally erect than in other species in the section, and the usually calcareous substrate is noteworthy. The deeply incised (usually not quite to base) leaflets are somewhat intermediate between the toothed leaflets of I. baileyi and the leaflets of I. shockleyi that are incised to the base into separate lobes. The individual leaflets of both I. baileyi and I. setosa are more or less flat and distichously paired; in I. shockleyi, groups of leaflet lobes are folded over onto each other, giving a verticillate appearance to the leaflet arrangement. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 236. | FNA vol. 9, p. 227. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae |
Sibling taxa | ||
Synonyms | Potentilla muirii | I. baileyi var. setosa, Potentilla baileyi var. setosa |
Name authority | A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873) | (S. Watson) Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 290. (1908) |
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