Horkelia daucifolia

(Greene) Rydberg

Bull. Torrey Bot. Club 25: 55. 1898.

Endemic
Basionym: Potentilla daucifolia Greene Pittonia 1: 160. 1888
Treatment appears in FNA Volume 9. Treatment on page 266. Mentioned on page 265, 267.
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Plants rosette-forming to tufted, rarely ± matted, grayish or green. Stems ascending to erect, 1.5–3.5 dm, hairs 2–3 mm proximally, glands sparse to dense distally. Basal leaves weakly planar to loosely cylindric, (4–) 5–12 (–17) × 0.8–3 (–4) cm, usually sericeous to villous, sometimes glabrate; stipules pinnately divided into 3–7 linear to filiform lobes; leaflets 5–10 per side, ± overlapping, obovate to broadly obcordate, 5–15 (–25) × 5–20 mm, ± as wide as long, divided 3/4+ to midrib into (0–) 2–15 linear to oblanceolate lobes 0.4–2 (–3) mm wide, these not restricted to apex. Cauline leaves 3–6; stipules 8–15 mm, deeply 3–7-lobed proximally, 1–3-lobed distally. Inflorescences open to ± congested, flowers arranged individually or in ± corymbiform clusters. Pedicels 2–10 (–20) mm. Flowers 10–15 mm diam.; epicalyx bractlets linear to linear-lanceolate, 2.5–3.5 × 0.5 mm, 2/3 to ± equal to length of sepals; hypanthium 1–1.5 × 3.5–5 mm, less than 1/2 as deep as wide, interior glabrous; sepals ± spreading, abaxially green, 3.5–7.5 mm; petals white to cream, often drying yellowish, cuneate to obcordate, (3.5–) 4–8 × 2–8 mm, apex ± emarginate, sometimes rounded; filaments 1–3 × 0.5–1.5 mm, anthers 0.5–0.8 mm; carpels 5–15, styles 2–4 mm. Achenes dark-brown, 2.4–3 mm, smooth to ± roughened.

Discussion

Varieties 3 (3 in the flora).

D. D. Keck (1938) decided that the leaflet characters previously used to recognize segregates of Horkelia daucifolia were random variables that have not become localized into geographic subunits. At the same time, he established subsp. latior D. D. Keck to accommodate a single collection with leaves approaching those of H. sericata, with the speculation that the population was an amphiploid derivative of the two species. Subsequent collections from the same general area (Scott Mountain, Siskiyou County, California) provide a full range of variation between the extreme with exceptionally wide leaflet lobes and the typical form occurring at the base of the mountain. This variant of the species is accordingly not recognized here, but the extremes with narrower, more numerous leaflet lobes are recognized as varieties that coincide with major river drainages (B. Ertter and J. L. Reveal 2007).

In the descriptions below, the pedicels of all varieties are sparsely pilose in addition to being puberulent or not.

Selected References

None.

Key

1 Leaflet lobes 2–5(–8), linear to oblanceolate, 1–2(–3) mm wide; petals cuneate to obovate, 2–4 mm wide. Horkelia daucifolia var. daucifolia
1 Leaflet lobes (2–)5–15, linear, 0.4–1 mm wide; petals broadly obovate to obcordate, 4–8 mm wide > 2
2 Pedicels 2–7(–10) mm, puberulent, eglandular; Oregon. Horkelia daucifolia var. caruifolia
2 Pedicels 5–10(–20) mm, not puberulent, minutely glandular; California. Horkelia daucifolia var. indicta

"thin" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Horkelia daucifolia"
smooth +  and more or less roughened +
2.4mm +  and 3mm +
shorter than wide +  and longer +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
rounded +
Barbara Ertter +  and James L. Reveal +
(Greene) Rydberg +
compound +  and simple +
opposite +  and alternate +
12 cm120 mm <br />0.12 m <br /> (17 cm170 mm <br />0.17 m <br />) +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 m <br />) +
weakly planar;loosely cylindric +
0.8 cm8 mm <br />0.008 m <br /> (3 cm30 mm <br />0.03 m <br />) +
flattened +
Potentilla daucifolia +
30 cm300 mm <br />0.3 m <br /> (40 cm400 mm <br />0.4 m <br />) +
planar +  and cylindric +
2 cm20 mm <br />0.02 m <br /> (30 cm300 mm <br />0.3 m <br />) +
coriaceous +
reduced +
free +  and distinct +
open to congested +
Calif. +  and Oreg. +
not +  and aggregated +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
linear +  and linear-lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
flattened +
0.5mm;1.5mm +
in more or less corymbiform clusters +  and arranged +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
obliquely ovoid +  and reniform +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
sparse +  and dense +
noncapitate +  and capitate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
pilose +  and glabrous +
0 +  and 1/2 +
0.1 cm1 mm <br />0.001 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
crassinucellate +
opposite +  and alternate +
marcescent +
winter-persistent +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
divided +, obovate +  and broadly obcordate +
0.5 cm5 mm <br />0.005 m <br /> (?) +  and 2 cm20 mm <br />0.02 m <br /> (?) +
linear +  and oblanceolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (?) +  and 0.2 cm2 mm <br />0.002 m <br /> (?) +
palmate +  and pinnate +
shallowly toothed +  and deeply divided +
aromatic +
inferior +  and superior +
clustered +, biseriate +  and superposed +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0 (?) +  and 4 (?) +
yellowish +, white +  and cream +
free +  and distinct +
cuneate;obcordate +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
adnate +, free +, connate +  and distinct +
Bull. Torrey Bot. Club +
not arillate +
linear;filiform +
persistent +
free +  and distinct +
obtuse +  and acute +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
free +  and distinct +
branched +  and simple +
stramineous +, reddish +  and green +
ascending +  and erect +
1 +  and 10 +
palmate +  and pinnate +
1-3-lobed;3-7-lobed;divided +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Ambiguae +, Hirsutae +, Horkelia sect. Hirsutae +, Sericatae +  and Horkelia sect. Sericatae +
Horkelia daucifolia +
Horkelia sect. Tridentatae +
species +
inconspicuous +
enlarged +
green +  and grayish +
plant +, matted +  and rosette-forming +
hairy +  and inconspicuously conspicuously glandular +