Ivesia argyrocoma var. argyrocoma |
Rosaceae subfam. rosoideae |
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silver-hair ivesia |
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Habit | Plants silvery; glands obscured. | Herbs, shrubs, or subshrubs. |
Stems | prostrate to ascending, (0.3–)1–2.5(–3) dm. |
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Leaves | alternate, rarely opposite, pinnately compound, sometimes simple or palmately compound; stipules present, rarely absent. |
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Basal leaves | 4–8(–10) cm; sheathing base sparsely to densely strigose abaxially; stipules lanceolate, 1–2 mm; petiole (0.5–)1–3 cm, hairs abundant, spreading, (1–)3–5 mm; leaflets 25–35 per side, tightly overlapping, (1–)2–3.5 mm, lobes 2–3, elliptic to obovate or oval, hairs dense, appressed to ascending, 0.5–1.5 mm. |
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Cauline leaves | (1–)2–3. |
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Inflorescences | (5–)10–30-flowered, (1–)1.5–4(–6) cm diam., flowers arranged in 1–several ± tight glomerules of 10–20(–30) flowers. |
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Pedicels | 1–3 mm. |
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Flowers | 7–9 mm diam.; epicalyx bractlets mostly linear to narrowly ovate, 0.8–2(–2.5) mm; hypanthium cupulate, (1–)1.5–2 × (2–)2.5–3(–3.5) mm, 1/2–2/3 as deep as wide; sepals sometimes purple-suffused, 2–3(–4) mm, acute; petals white, obovate, (2–)3–4(–4.5) mm; stamens 20, filaments flattened, 0.6–1.3 mm, anthers yellowish, 0.3–0.5 mm; carpels 4–8, styles 1.5–2.2 mm. |
torus usually enlarged, sometimes small or absent; carpels 1–260(–450), distinct, free, styles distinct, rarely connate (Roseae); ovules 1(or 2), collateral (Rubeae) or superposed (Fallugia, Filipendula). |
Fruits | achenes or aggregated achenes sometimes with fleshy, urn-shaped hypanthium or enlarged torus, sometimes aggregated drupelets; styles persistent or deciduous, not elongate (elongate but not plumose in Geum). |
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Achenes | brown, (1.5–)2–2.5 mm. |
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x | = 7(8). |
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Ivesia argyrocoma var. argyrocoma |
Rosaceae subfam. rosoideae |
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Phenology | Flowering summer. | |
Habitat | Dry meadows, gravelly soil, in montane conifer woodlands | |
Elevation | 1400–2300 m (4600–7500 ft) | |
Distribution |
CA |
North America; Mexico; Central America; South America; West Indies; Bermuda; Eurasia; Africa; Atlantic Islands; Indian Ocean Islands; Pacific Islands; Australia |
Discussion | Of conservation concern. Variety argyrocoma is found only on so-called pebble plains in the eastern San Bernardino Mountains, San Bernardino County. The filaments are significantly more flattened than those of other species of Ivesia and approach those that characterize Horkelia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Variation in the number of genera in subfam. Rosoideae is due to differences in generic delimitation between D. Potter et al. (2007) and the authors of some Potentilleae genera. Cyanogenic glycosides and sorbitol are absent in the subfamily. Tribes 6, genera 28–35, species ca. 1600 (6 tribes, 26 genera, 302 species, including 1 hybrid, in the flora) (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 242. | FNA vol. 9, p. 23. |
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Subordinate taxa | ||
Name authority | unknown | Arnott: Botany, 107. (1832) |
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