Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Horkelia fusca

Horkelia fusca var. capitata

dusky, horkelia, pinewoods, pinewoods horkelia, tawny horkelia
Photo is of parent taxon

horkelia, Palouse horkelia
Stems

4–9 dm.
Basal leaves

(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.

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

1–5(or 6).

3–6;

leaflets of proximalmost 3–5 per side.
Inflorescences

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

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.

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

brown.

1.6–1.8 mm.

Horkelia fusca

Horkelia fusca var. capitata
Phenology Flowering summer.
Habitat Dry meadow edges, in conifer woodlands, mainly on volcanic or granitic soil
Elevation 100–2300 m [300–7500 ft]
Distribution
from FNA
CA; ID; NV; OR; WA; WY
[BONAP county map]
from FNA
ID; OR; WA
[BONAP county map]
Discussion

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.)

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.)
Parent taxa Rosaceae > subfam. Rosoideae > tribe Potentilleae > Horkelia > sect. Capitatae Rosaceae > subfam. Rosoideae > tribe Potentilleae > Horkelia > sect. Capitatae > Horkelia fusca
Sibling taxa
H. bolanderi, H. californica, H. clevelandii, H. congesta, H. cuneata, H. daucifolia, H. hendersonii, H. hispidula, H. howellii, H. marinensis, H. parryi, H. rydbergii, H. sericata, H. tenuiloba, H. tridentata, H. truncata, H. tularensis, H. wilderae, H. yadonii
H. fusca var. brownii, H. fusca var. filicoides, H. fusca var. fusca, H. fusca var. parviflora, H. fusca var. pseudocapitata, H. fusca var. tenella
Subordinate taxa
H. fusca var. brownii, H. fusca var. capitata, H. fusca var. filicoides, H. fusca var. fusca, H. fusca var. parviflora, H. fusca var. pseudocapitata, H. fusca var. tenella
Key
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
Synonyms Potentilla douglasii H. capitata, H. fusca subsp. capitata, Potentilla capitata, P. douglasii var. capitata
Name authority Lindley: Edwards’s Bot. Reg. 23: plate 1997. (1837) (Lindley) M. Peck: Man. Pl. Oregon, 398. (1941)
Source FNA vol. 9, p. 259. Treatment authors: Barbara Ertter, James L. Reveal. FNA vol. 9, p. 261. Treatment authors: Barbara Ertter, James L. Reveal.
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Boraginaceae and Polemoniaceae.)

The species comparison tool is brought to you by:
Northwest Wildflowers