Ivesia utahensis |
Ivesia longibracteata |
|
---|---|---|
Utah ivesia, Utah mousetail |
Castle Crags ivesia, longbract mousetail |
|
Habit | Plants green, rosetted to tufted; taproot proximally enlarged, not fleshy. | Plants green, ± tufted; taproot ± stout, not fleshy. |
Stems | prostrate to ascending, 0.5–1.5(–2) dm. |
ascending to erect, 0.3–1.2 dm. |
Basal leaves | ± tightly cylindric, 2–7(–9) cm; sheathing base glabrous abaxially; petiole 0.5–2 cm, hairs 0.5–1 mm; leaflets 15–20 per side, 2–4 mm, glabrate or sparsely short-hirsute, sparsely to densely glandular, lobes (2–)3–8, narrowly oblanceolate to obovate, apex not setose. |
weakly planar to loosely ± cylindric, (0.5–)2–4(–6) cm; sheathing base glandular abaxially, otherwise glabrous; petiole 0.5–2 cm, hairs 0.2–1 mm; leaflets 5–6 per side, 2–6 mm, ± short-hirsute, glandular-puberulent, lobes 2–7, oblanceolate to spatulate or obovate, apex not setose. |
Cauline leaves | (0–)1, not paired. |
1–3, not paired. |
Inflorescences | (5–)10–30-flowered, 1–2.5(–5) cm diam.; glomerules 1–few. |
3–14-flowered, 1–2.5 cm diam.; glomerules 1. |
Pedicels | 1–7 mm. |
1.5–6 mm. |
Flowers | 7–9 mm diam.; epicalyx bractlets narrowly oblong to oval, 0.8–2 mm; hypanthium shallowly cupulate, (1–)1.5–2 × 2.5–3.5 mm; sepals (1.8–)2–3 mm, acute; petals white, sometimes pink-tinged, oblanceolate to spatulate, 1.8–3 mm; stamens 5, filaments 1.3–1.8 mm, anthers orangish to reddish brown, 0.4–0.6 mm; carpels (1–)2–4, styles 1.5–2 mm. |
8–10 mm diam.; epicalyx bractlets linear to narrowly lanceolate or elliptic, 2.5–5 mm, longer than sepals; hypanthium shallowly cupulate, 0.5–1 × 2–3 mm; sepals 1.5–2.5 mm, ± acute; petals pale yellow, linear to narrowly oblanceolate, 1.5–2.5 mm; stamens 5, filaments 0.7–1.3 mm, anthers yellow, 0.5–0.8 mm; carpels 6–11, styles 1–1.5 mm. |
Achenes | yellowish green to light tan or gray-brown, 1.7–1.9 mm. |
cream to light tan, 1.2–1.5 mm. |
Ivesia utahensis |
Ivesia longibracteata |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Talus slopes, bare ridges, in high-elevation sagebrush communities, subalpine to alpine conifer woodlands | Dry crevices of granodioritic igneous rock, in mixed oak-conifer woodlands |
Elevation | 3200–3700 m (10500–12100 ft) | 1200–1400 m (3900–4600 ft) |
Distribution |
UT |
CA |
Discussion | Of conservation concern. Ivesia utahensis is known from the Wasatch and adjacent Uinta Mountains in northern Utah. The species stands as the white-petaled counterpart to the yellow-petaled Sierran I. lycopodioides, possibly indicating a common ancestral stock that was once more continuous across the Great Basin. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Ivesia longibracteata is known only from the Castle Crags area of Shasta County. The epithet alludes to a diagnostic characteristic unique in the genus: the epicalyx bractlets are longer than the sepals. The plants grow on vertical rock faces, a habitat more characteristic of sect. Setosae; however, the stems are ascending to erect and do not form hanging clumps, and the pedicels are not curved in fruit. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 233. | FNA vol. 9, p. 236. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Potentilla utahensis | |
Name authority | S. Watson: Proc. Amer. Acad. Arts 17: 371. (1882) | Ertter: Syst. Bot. 14: 233, fig. 1. (1989) |
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