Horkelia sericata
Horkelia cuneata
Howell's horkelia, silky horkelia
wedge leaf horkelia
ascending to erect, 1.5–4.5 dm, hairs 1 mm proximally, glands absent or sparse distally.
decumbent to erect, (1–)2–6(–7.5) dm, hairs ascending to appressed, sometimes spreading.
± cylindric to weakly planar, 3–10 × 0.3–1.2 cm, densely sericeous, often villous on margins apically;
stipules usually entire or forked, rarely pinnately divided into linear lobes;
leaflets (8–)10–20 per side, ± overlapping, elliptic to flabellate, 2–8 × 1–4 mm, 1/2–2/3 as wide as long, divided ± 1/2+ to midrib into (0–)2–4 elliptic lobes 1–2 mm wide, these not restricted to apex.
planar, (5–)10–30 × 1.5–4(–5) cm;
stipules entire or basally lobed;
leaflets 5–12 per side, separate to slightly overlapping, ± elliptic to obovate or oblanceolate, 5–25(–30) × 5–15(–25) mm, ± 1/2 to nearly as wide as long, divided less than 1/3 to midrib into (5–)10–15 oblanceolate to obovate teeth, sparsely pilose to glabrate or sericeous.
(2 or)3–5;
stipules 3–8 mm, entire or shallowly 1–2-toothed.
1–3(–5).
open, flowers arranged individually and/or in non-capitate glomerules.
± open to congested, flowers arranged individually and/or in glomerules.
1–4 mm.
1–30(–40) mm.
10 mm diam.;
epicalyx bractlets linear-lanceolate, 1.5–3 × 0.5 mm, ± 2/3 length of sepals;
hypanthium 1–1.5 × 2–3 mm, ± 1/2 to as deep as wide, interior glabrous;
sepals spreading to reflexed, abaxially green to reddish or purplish, 2–4 mm;
petals white to pink or red-veined, narrowly obcordate, 3–4.5(–7) × 2–3 mm, apex ± emarginate;
filaments 0.5–1.5 × 0.2–0.5 mm, anthers 0.4–0.6 mm;
carpels 2–6;
styles 1.5–2 mm.
12–17 mm diam.;
epicalyx bractlets lanceolate to ovate, 3–5 × 1.5–3 mm, 2/3–3/4 length of sepals, entire;
hypanthium 1.5–2 × 4–7 mm, less than 1/2 as deep as wide, interior glabrous or pilose in a narrow ring;
sepals ± reflexed to spreading, lanceolate, 4–6.5 mm;
petals oblanceolate to narrowly obovate, 4–8 × 1.5–4 mm, apex obtuse to rounded;
filaments 1–3 × 0.5–2 mm, anthers 0.7–1.1 mm;
carpels (30–)40–60(–80);
styles 2–3 mm.
brown, 2–2.5 mm, smooth.
brown, 1.5–1.8 mm, smooth or minutely rugose.
= 28.
Horkelia sericata
Horkelia cuneata
Of conservation concern.
D. D. Keck (1938) expanded the circumscription of Horkelia sericata to encompass the plants segregated here as H. howellii, on the grounds that intergradation is too extensive to justify taxonomic recognition of the extremes. In this evaluation, however, most collections can be unequivocally divided between plants with compact silvery-sericeous leaves with entire or forked stipules (H. sericata), and plants with larger, greener leaves and pinnately divided stipules (H. howellii). It is not known if the chromosome count provided by P. A. Munz (1959) was derived from H. howellii or H. sericata.
As here circumscribed, Horkelia sericata is a localized taxon known only from Curry County, Oregon, and the Gasquet serpentine area in adjacent Del Norte County, California.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 3 (3 in the flora).
As noted by D. D. Keck (1938) and B. Ertter (1997b), recognition of subunits within Horkelia cuneata is complicated by the abundance of intermediates, to the extent that a complete transition exists between the decumbent, densely hairy coastal extreme with a congested inflorescence, represented by var. sericea, and the erect, green-glandular interior extreme with an open inflorescence, represented by var. puberula. The traditional division into three infraspecific units is maintained here to emphasize the distinctiveness of the extremes, which would qualify as specifically distinct were they not ends of a continuum. The extremes are furthermore threatened by ongoing decimation of suitable habitats at the northern (San Francisco Bay Area) and southern (greater Los Angeles) ends of the species range.
Determining the correct name of Horkelia cuneata if treated as a species of Potentilla is complicated. Potentilla cuneata (Lindley) Baillon ex Munz & I. M. Johnston (1925) and P. puberula Greene are both later homonyms, while P. multijuga Lehmann has been conserved with a conserved type to maintain established usage for an unrelated species of Potentilla (B. Ertter and J. L. Reveal 2008). J. T. Howell (1945) adopted P. lindleyi; however, as noted by R. F. Hoover (1966), P. kelloggii has priority at species rank by a matter of months. The latter is accordingly the correct name in Potentilla for H. cuneata.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants: eglandular hairs sparse or absent, glandular hairs evident; hypanthium interior rim usually glabrous, sometimes sparsely pilose; pedicels (2–)5–10 mm, proximalmost to 40 mm; stems erect. | var. puberula |
1. Plants: eglandular hairs moderately abundant to dense, glandular hairs evident or obscured; hypanthium interior rim ± or densely pilose; pedicels 1–5 mm, proximalmost to 15 mm; stems decumbent to erect | → 2 |
2. Plants ± green, eglandular hairs moderately abundant, spreading to ascending, glandular hairs usually evident; stems ascending to erect. | var. cuneata |
2. Plants grayish-sericeous, eglandular hairs dense, ascending to appressed, glandular hairs obscured; stems decumbent to ascending. | var. sericea |
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
