Horkelia fusca
Horkelia tridentata
dusky, horkelia, pinewoods, pinewoods horkelia, tawny horkelia
Barton Flats or wilder's horkelia, cluster horkelia, three tooth horkelia
decumbent to nearly erect, 0.5–4(–7) dm, hairs 1–3 mm proximally, glands absent or sparse distally.
(3–)4–20(–40) × (1–)1.5–4(–7) cm;
leaflets narrowly cuneate to obovate to flabellate, 5–30(–35) × 2–20(–30) mm, 1/3 as wide to wider than long, divided into linear or oblanceolate to obovate teeth or lobes, sparsely to ± densely short-villous or hirsute, sometimes glabrate.
planar, 3–12 × 1–3(–4) cm, usually sericeous to villous, sometimes glabrate adaxially;
stipules entire or rarely forked or pectinate;
leaflets 2–5(or 6) per side, separate to slightly overlapping, elliptic to cuneate-oblong, (3–)5–20(–30) × 1.5–7(–10) mm, (1/4–)1/3–1/2 as wide as long, divided 1/10–1/6 or less to midrib into (0–)3(or 4) triangular teeth 1 mm wide, these restricted to apex.
1–5(or 6).
1–5;
stipules 3–12 mm, entire or deeply 3–5-lobed, lanceolate to ovate.
open to congested, flowers arranged in ± capitate glomerules or in ± corymbiform clusters.
(1–)2–6(–10) mm.
5–12 mm diam.;
epicalyx bractlets 1–3 mm, 1/2 length of to nearly equal to sepals;
hypanthium 1–3 × 2–4 mm, 1/2 to nearly as deep as wide;
sepals spreading to ± reflexed, narrowly to broadly lanceolate, (1.7–)2–4(–4.5) mm;
petals 2–6(–6.5) mm;
filaments 0.2–1.5 × (0.2–)0.4–0.6(–1) mm, anthers 0.4–0.6 mm;
styles 0.9–1.5 mm.
4–10 mm diam.;
epicalyx bractlets linear to narrowly elliptic, 0.8–2(–3) × 0.2–0.4 mm, 1/2–2/3 length of sepals;
hypanthium 1–2.5 × 2–5 mm, 1/2 to nearly as deep as wide, interior glabrous or pilose;
sepals moderately reflexed, abaxially green to reddish, 1.5–3 mm;
petals white, sometimes tinged with pink, linear to broadly oblanceolate, (1–)1.5–4(–4.5) × 0.3–1.5 mm, apex acute to rounded or mucronate;
filaments 0.5–2 × 0.1–0.4(–0.8) mm, anthers 0.2–0.5 mm;
carpels 5–15;
styles 1–2.5 mm.
brown.
light brown, 1.5–2.5 mm, rugose.
Horkelia fusca
Horkelia tridentata
Varieties 7 (7 in the flora).
Horkelia fusca represents the primary radiation of the genus beyond the California Floristic Province. Within California, H. fusca occurs in the Sierra Nevada and mountains of northern California, and it is the only representative of the genus extending beyond California and Oregon into Washington, Idaho, Nevada [with the possible exception of H. tridentata (10e. sect. Tridentatae) in Washoe County], and, questionably, Wyoming.
As here circumscribed, Horkelia fusca is the most diverse, most widely distributed species in the genus, with significant additional work needed to fully elucidate its variation patterns. The treatment presented here differs from that of D. D. Keck (1938) and B. Ertter (1993d) in using the rank variety instead of subspecies, circumscribing var. capitata more narrowly, and transferring the application of var. pseudocapitata from what is here called var. brownii to the bulk of what had been subsp. capitata (Lindley) D. D. Keck (B. Ertter and J. L. Reveal 2007).
There are two types of basal leaves in plants of Horkelia fusca. The ephemeral early-season leaves have leaflets that tend to be broadly cuneate-obovate, shallowly toothed, densely glandular but otherwise sparsely hairy, and deeply veined. The leaf features described below are drawn from the more persistent, mid season leaves that predominate at peak flowering and differ more strongly among varieties.
Petals of first-formed flowers are often larger than average; end-of-season petals can be smaller than average.
Although Montana is sometimes included in the range of Horkelia fusca, such references are based only on potential occurrence (W. E. Booth and J. C. Wright 1959).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
Rydberg established Horkelia flavescens on the basis of its more congested inflorescence, purportedly yellowish petals, and broader filaments. As noted by D. D. Keck (1938), the petals are usually white, at least when fresh, and the other characters are highly variable; he reduced H. flavescens to a subspecies of H. tridentata, which is here treated at the rank of variety. In general, var. flavescens tends to be more decumbent with a single, loosely congested flower cluster and broader petals; these characters completely overlap and can vary independently. The presence or absence of hairs on the hypanthium interior is the single most reliably diagnostic character and is the primary determiner of the geographic distributions presented here. The exception is a cluster of populations from the extreme southern end of the coastal range of var. flavescens in Colusa, Lake, and Mendocino counties, California, which have glabrous hypanthia but otherwise have all the diagnostic characters of var. flavescens. Although provisionally included here within var. flavescens, these populations may be better treated as a separate variety.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaflets divided ± 1/2–3/4+ to midrib | → 2 |
1. Leaflets divided less than 1/2 to midrib | → 4 |
2. Inflorescences usually with flowers arranged individually; sw Oregon. | var. filicoides |
2. Inflorescences composed of 3–20-flowered glomerules, (flowers rarely arranged individually in var. fusca); ne California, nw Oregon, sw Washington | → 3 |
3. Leaflets divided ± 1/2 to midrib, 5–18(–20) × 4–15 mm; petals 3–5 mm; filaments 0.5–1.3 mm, longer than wide; nw Oregon, sw Washington. | var. fusca |
3. Leaflets divided 3/4+ to midrib, 5–10(–15) × 2–10(–20) mm; petals 2–3(–4) mm; filaments 0.2–0.5 mm, wider than long; ne California. | var. tenella |
4. Leaves grayish, surfaces often obscured, ± densely short-villous; leaflets narrowly to broadly cuneate, usually 1/3–1/2 as wide as long; ne California, adjacent Oregon and Nevada. | var. brownii |
4. Leaves green, surfaces not obscured, ± short-hirsute, villous, or glabrate; leaflets cuneate to broadly obovate, 1/2 to wider than long; California to Washington, Idaho, Wyoming | → 5 |
5. Inflorescences dark reddish purple, densely congested, bracts acuminate-lobed, obscuring pedicels and flowers even at maturity, glandular hairs usually conspicuously red-septate; epicalyx bractlets (2–)3.5–5(–6) mm; cauline leaves 3–6, leaflets of proximalmost 3–5 per side; ne Oregon, se Washington, n Idaho. | var. capitata |
5. Inflorescences green to reddish purple, congested to open, bracts acute-lobed, not obscuring pedicels and flowers at maturity, glandular hairs not or obscurely red-septate; epicalyx bractlets 1–3.5(–4) mm; cauline leaves 1–4(or 5), leaflets of proximalmost 2–4(or 5) per side; Cascade-Sierra axis of Oregon, California, e to Wyoming and n Nevada | → 6 |
6. Petals (3–)4–6 mm; leaflets 10–30(–35) × (5–)10–20(–25) mm; epicalyx bractlets 2–3.5(–4) mm; mountains in and bordering n Intermountain Region, ne California, n Nevada, se Oregon, s Idaho. | var. pseudocapitata |
6. Petals 2–4.5(–6.5) mm; leaflets 5–15(–20) × (2–)5–10(–15) mm; epicalyx bractlets 1–2(–3) mm; Sierra Nevada, California and Nevada, to Cascade Ranges, c Oregon, and mountains of c Idaho, adjacent Wyoming. | var. parviflora |
1. Hypanthium interior glabrous; petals linear to oblanceolate, usually ± equal to or longer than sepals; inflorescences composed of 1+ ± capitate glomerules, these sometimes expanding with age. | var. tridentata |
1. Hypanthium interior pilose (except in some North Coast Ranges of California); petals ± broadly oblanceolate, often shorter than sepals; inflorescences composed of usually 1 ± corymbiform cluster. | var. flavescens |
CA
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
