Horkelia fusca var. tenella

S. Watson in W. H. Brewer et al.

in W. H. Brewer et al., Bot. California 1: 181. 1876.

Common names: Delicate horkelia
Endemic
Synonyms: Horkelia fusca subsp. tenella (S. Watson) D. D. Keck Potentilla douglasii var. tenella (S. Watson) Greene
Treatment appears in FNA Volume 9. Treatment on page 261. Mentioned on page 260, 263.

Stems (0.6–) 1–4 (–5) dm. Basal leaves green, (3–) 4–18 (–27) cm; leaflets 8–15 per side, cuneate to flabellate, 5–10 (–15) × 2–10 (–20) mm, 3/4 as wide to wider than long, divided 3/4+ to midrib into 5–15 lobes or teeth, surfaces not obscured, sparsely short-hirsute to glabrate. Cauline leaves 2–4 (or 5); leaflets of proximalmost 3–6 per side. Inflorescences green to ± reddish, congested to open, comprising no more than 1/4 of stem, composed of 3–10 (–20) -flowered glomerules, glandular-hairs sometimes red-septate; bracts acute to acuminate-lobed, sometimes partly obscuring pedicels and flowers at maturity. Flowers: epicalyx bractlets 1.5–2 mm; hypanthium 1.5–2 × 2–3 mm; petals 2–3 (–4) mm; filaments 0.2–0.5 mm, wider than long, anthers 0.5 mm; styles 1 mm. Achenes 1.2–1.5 mm. 2n = 28.


Phenology: Flowering summer.
Habitat: Dry meadow edges, open conifer woodlands, mainly on volcanic soil
Elevation: 1200–2200 m

Discussion

Plants of var. tenella have the most deeply and consistently divided leaflets, and the variety is the only one with such leaflets that occurs in California. It is most common in open lodgepole pine forests at the southern end of the Cascade Range in northeastern California. Populations outside this core area tend to intergrade with var. brownii or var. parviflora. A collection from west-central Tehama County (Bracelin 405, UC) matches this variety, but from an atypical habitat well outside the core range.

Selected References

None.

Lower Taxa

None.

"/2lengthoftonearlyequaltosepals" is not declared as a valid unit of measurement for this property."wider than long" is not a number."wide to wider than long" is not a number."dm" is not declared as a valid unit of measurement for this property.

1.2mm +  and 1.5mm +
longer than wide +
0.5 cm5 mm <br />0.005 m <br /> (?) +
pink +  and rose +
Barbara Ertter +  and James L. Reveal +
S. Watson in W. H. Brewer et al. +
compound +  and simple +
opposite +  and alternate +
20 cm200 mm <br />0.2 m <br /> (40 cm400 mm <br />0.4 m <br />) +
18 cm180 mm <br />0.18 m <br /> (27 cm270 mm <br />0.27 m <br />) +
4 cm40 mm <br />0.04 m <br /> (7 cm70 mm <br />0.07 m <br />) +
4 cm40 mm <br />0.04 m <br /> (20 cm200 mm <br />0.2 m <br />) +
4 cm40 mm <br />0.04 m <br /> (18 cm180 mm <br />0.18 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
flattened +
Capitatae +
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 />) +
acute +  and acuminate-lobed +
reduced +
free +  and distinct +
Delicate horkelia +
open to congested +
not +  and aggregated +
1200–2200 m +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
flattened +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 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 />) +
3-10(-20)-flowered +
Dry meadow edges, open conifer woodlands, mainly on volcanic soil +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
congested +  and open +
green +  and more or less reddish +
crassinucellate +
opposite +  and alternate +
marcescent +
winter-persistent +
overlapping +  and separate +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
glabrate +, sparsely +  and more or less densely short-villous or hirsute +
divided +, cuneate +  and flabellate +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 1 cm10 mm <br />0.01 m <br /> (?) +
oblanceolate +
palmate +  and pinnate +
shallowly toothed +  and deeply divided +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0 (?) +  and 4 (?) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
free +  and distinct +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
in W. H. Brewer et al., Bot. California +
not arillate +
0.4 cm4 mm <br />0.004 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
persistent +
free +  and distinct +
spreading +  and more or less reflexed +
lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
free +  and distinct +
branched +  and simple +
stramineous +, reddish +  and green +
ascending +  and erect +
/4 +, 1 +  and no +
palmate +  and pinnate +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
1 cm10 mm <br />0.01 m <br /> (?) +
not obscured +
sparsely short-hirsute +  and glabrate +
Horkelia fusca subsp. tenella +  and Potentilla douglasii var. tenella +
Horkelia fusca var. tenella +
Horkelia fusca +
variety +
5 +  and 15 +
oblanceolate +  and obovate +
inconspicuous +
enlarged +
grayish +, reddish +  and green +
hairy +  and inconspicuously conspicuously glandular +