Ivesia saxosa |
Ivesia cryptocaulis |
|
---|---|---|
rock ivesia, rock mousetail |
Charleston Peak ivesia, Charleston Peak mousetail |
|
Habit | Plants green, ± tufted, often forming hanging clumps, sometimes rosetted. | Plants green, diffusely matted. |
Stems | pendent or prostrate to ascending, 0.4–2.6(–3) dm. |
prostrate to decumbent, 0.2–0.6(–1) dm. |
Basal leaves | 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. |
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 | 1–2(–4); blade well developed. |
1(–2); blade vestigial. |
Inflorescences | (1–)3–30(–60)-flowered, open, (0.5–)2–8 cm diam. |
1–10-flowered, ± congested, 0.5–1.5 cm diam. |
Pedicels | (5–)10–30 mm. |
3–7(–10) mm. |
Flowers | 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. |
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 | greenish white to light tan, 1–1.8 mm, faintly rugose, ± carunculate. |
greenish cream to light brown, 1.4–1.8(–2) mm, smooth, not carunculate. |
Ivesia saxosa |
Ivesia cryptocaulis |
|
Phenology | Flowering late spring–summer. | Flowering summer. |
Habitat | 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 | Dry to moist limestone gravel, scree, or talus slopes and outcrops, subalpine conifer woodlands, alpine tundra communities |
Elevation | 900–3300 m (3000–10800 ft) | 2500–3700 m (8200–12100 ft) |
Distribution |
CA; Mexico (Baja California)
|
NV |
Discussion | 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.) |
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. 223. | FNA vol. 9, p. 228. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae |
Sibling taxa | ||
Synonyms | Potentilla saxosa, P. acuminata, P. saxosa subsp. sierrae | Potentilla cryptocaulis |
Name authority | (Lemmon ex Greene) Ertter: Syst. Bot. 14: 232. (1989) | (Clokey) D. D. Keck: Lloydia 1: 130. (1939) |
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