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Photo is of parent taxon

Diamond Lake horkelia, pinewoods horkelia

Photo is of parent taxon

horkelia, Palouse horkelia

Stems

(1–)1.5–3.5(–4) dm.

4–9 dm.

Basal leaves

green, 4–9(–12) cm;

leaflets 4–8 per side, cuneate-obovate, 5–12 × 2–8 mm, ± 1/2 as wide as long, divided ± 1/2+ to midrib into 3–9 teeth or lobes, surfaces not obscured, sparsely short-villous to glabrate.

green, 10–20(–35) cm;

leaflets 4–6(–8) per side, cuneate to broadly obovate, 10–30(–35) × 10–25(–30) mm, 1/2 to as wide as long; divided 1/5–1/4 to midrib into 8–15 teeth, surfaces not obscured, ± sparsely short-hirsute to glabrate.

Cauline leaves

2–4(–6);

leaflets of proximalmost 2–5 per side.

3–6;

leaflets of proximalmost 3–5 per side.

Inflorescences

green, open, comprising 1/3–1/2 of stem, flowers usually arranged individually, glandular hairs sometimes red-septate;

bracts acuminate-lobed, not obscuring pedicels and flowers at maturity.

dark reddish purple, densely congested, comprising no more than 1/6 of stem, composed of 5–30-flowered glomerules, glandular hairs usually conspicuously red-septate;

bracts acuminate-lobed, obscuring pedicels and flowers even at maturity.

Flowers

epicalyx bractlets 1–2 mm;

hypanthium 1–2 × 2.5–3.5 mm;

petals 2–4(–5) mm;

filaments 0.5–1 mm, ± as wide as long, anthers 0.5 mm;

styles 1 mm.

epicalyx bractlets (2–)3.5–5(–6) mm;

hypanthium 2–3 × 3–5 mm;

petals 4–6.5 mm;

filaments 0.5–1.5 mm, longer than wide, anthers 0.5–0.6 mm;

styles 1–1.5 mm.

Achenes

1.2–1.5 mm.

1.6–1.8 mm.

Horkelia fusca var. filicoides

Horkelia fusca var. capitata

Phenology Flowering summer. Flowering summer.
Habitat Open conifer woodlands, mainly on volcanic soil Dry meadow edges, in conifer woodlands, mainly on volcanic or granitic soil
Elevation 800–1600 m (2600–5200 ft) 100–2300 m (300–7500 ft)
Distribution
from FNA
OR
[BONAP county map]
from FNA
ID; OR; WA
[BONAP county map]
Discussion

Variety filicoides is known from the southern Cascade Range of southwestern Oregon, primarily in open lodgepole pine forests north and west of Crater Lake. This is the only variety in which the flowers are usually arranged individually rather than clustered into glomerules, at least in fully expanded inflorescences; some populations out of the core range have more congested inflorescences and are transitional to var. parviflora in this regard.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

As here circumscribed, var. capitata is found in meadow margins and grassy openings in the forested mountains surrounding the Palouse Prairie (in the broad sense) of northern Idaho, southeastern Washington, and northeastern Oregon. This is a significantly more limited range than accepted by D. D. Keck (1938) and in subsequent floras (for example, B. Ertter 1993d), with the bulk of what had been treated as var. (or subsp.) capitata here treated as var. pseudocapitata. The distinctions between the two varieties are more matters of degree than absolute differences, var. capitata generally having more congested, more purple, more glandular inflorescences in which the pedicels and hypanthia remain covered by larger involucral bracts divided into more elongate teeth. Plants of var. capitata can also be significantly larger, especially in the remnant prairie patches of northern Idaho, with more numerous cauline leaves having more pairs of larger leaflets. The extremes of the two varieties are reasonably distinct, with a significant biogeographic underpinning, but the differences merge in the Blue Mountains of Oregon.

Given the California focus of the published source (P. A. Munz 1959), the chromosome count of 2n = 28 for var. capitata is most likely based on material here treated as var. pseudocapitata.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 260. FNA vol. 9, p. 261.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Potentilleae > Horkelia > sect. Capitatae > Horkelia fusca Rosaceae > subfam. Rosoideae > tribe Potentilleae > Horkelia > sect. Capitatae > Horkelia fusca
Sibling taxa
H. fusca var. brownii, H. fusca var. capitata, H. fusca var. fusca, H. fusca var. parviflora, H. fusca var. pseudocapitata, H. fusca var. tenella
H. fusca var. brownii, H. fusca var. filicoides, H. fusca var. fusca, H. fusca var. parviflora, H. fusca var. pseudocapitata, H. fusca var. tenella
Synonyms Potentilla douglasii var. filicoides, H. fusca subsp. filicoides H. capitata, H. fusca subsp. capitata, Potentilla capitata, P. douglasii var. capitata
Name authority (Crum) M. Peck: Man. Pl. Oregon, 399. (1941) (Lindley) M. Peck: Man. Pl. Oregon, 398. (1941)
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