Horkelia tridentata var. flavescens
Rosaceae subfam. rosoideae
hairycup horkelia, pale horkelia, three tooth horkelia
± decumbent, 0.5–2.5(–4.5) dm.
alternate, rarely opposite, pinnately compound, sometimes simple or palmately compound;
stipules present, rarely absent.
composed of usually 1 3–25-flowered ± corymbiform cluster.
6–10 mm diam.;
hypanthium 2.5–5 mm diam., interior pilose (except in some North Coast Ranges populations);
petals ± broadly oblanceolate, (1–)1.5–3(–4) × 0.5–1.5 mm, often shorter than sepals, apex obtuse to rounded or mucronate;
filaments 1–2 × 0.2–0.4(–0.8) mm, anthers 0.3–0.5 mm;
styles 1.5–2.5 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).
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).
2–2.5 mm, strongly rugose.
= 7(8).
Horkelia tridentata var. flavescens
Rosaceae subfam. rosoideae
Variety flavescens occurs primarily in the mountains of northwestern California, from Mendocino to Siskiyou counties. A single collection is confirmed from Curry County, Oregon (Bear Camp Trail, Leach 4554, OSC); other collections from Curry and Josephine counties may be hybrids between this variety and Horkelia congesta var. nemorosa. A second cluster of populations occurs in central Plumas and adjacent Lassen counties, California, and historic collections are known from near Truckee on the border of Nevada and Placer counties, California. D. D. Keck (1938) suggested that this bicentric distribution may have resulted from the independent coalescence of the diagnostic characteristics of var. flavescens. The locality of a collection purportedly from Washoe County, Nevada (80 miles north of Reno, Brooks s.n., RENO) needs to be confirmed.
(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.)
CA
OR
Flora NW
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WildflowerSearch
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