Ivesia muirii |
Rosaceae tribe Potentilleae |
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granite mousetail, Muir's ivesia |
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Habit | Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy. | Herbs, perennial, rarely annual or biennial, shrubs, or subshrubs; unarmed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Stems | usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm. |
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Leaves | alternate, rarely opposite, pinnately (palmately) compound (simple in Alchemilla, Aphanes, and Chamaerhodos); stipules persistent (absent in Chamaerhodos), adnate to petiole; venation pinnate or palmate. |
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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. |
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Cauline leaves | (0–)1–2, paired if 2. |
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Inflorescences | 10–30-flowered, 1–2(–3.5) cm diam.; glomerules usually 1. |
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Pedicels | 0.3–2(–3.5) mm. |
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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. |
perianth and androecium perigynous; epicalyx bractlets present, sometimes absent; hypanthium usually patelliform, cupulate, or campanulate, sometimes turbinate, saucer-shaped, flat-bottomed, or subglobose to ellipsoid or ovoid; torus flat to conic or turbinate, enlarged (absent or reduced in Alchemilla, Aphanes, and Chamaerhodos); carpels 1–260, styles basal or lateral to subterminal, distinct; ovules 1(or 2), basal. |
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Fruits | aggregated achenes (achenes in Alchemilla and Aphanes); torus sometimes fleshy; styles deciduous or persistent, not elongate. |
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Achenes | grayish brown, mottled with red, 1.6–2 mm. |
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Ivesia muirii |
Rosaceae tribe Potentilleae |
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Phenology | Flowering summer. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Habitat | Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Elevation | 2900–4000 m (9500–13100 ft) | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Distribution |
CA
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North America; Mexico; Central America; South America; West Indies; Bermuda; Eurasia; Africa; Atlantic Islands; Pacific Islands; Australia |
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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.) |
Genera 14–22, species ca. 860 (14 genera, 189 species, including 1 hybrid, in the flora area). The base chromosome number for Potentilleae is mostly x = 7 (8 in Alchemilla and Aphanes; 14 in Comarum). Variation in the number of genera recognized in Potentilleae is due to differences in generic delimitation between D. Potter et al. (2007) and the authors of Potentilla and segregates here (see 9. Ivesia and 8. Potentilla for discussion). In the former, Duchesnea, Horkelia, Horkeliella, and Ivesia are included within Potentilla. Likewise, Aphanes is included within Alchemilla by Potter et al. while it is kept distinct here. Potentilla and its segregates and Fragaria are host to Phragmidium rusts, but not the other genera of the tribe. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 9, p. 236. | FNA vol. 9, p. 119. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia | Rosaceae > subfam. Rosoideae | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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Synonyms | Potentilla muirii | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873) | Sweet: Brit. Fl. Gard. 2: sub plate 124. (1825) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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