Horkelia yadonii

Ertter

Syst. Bot. 18: 139, fig. 2. 1993.

Common names: Yadon’s or Santa Lucia horkelia
Conservation concernEndemic
Treatment appears in FNA Volume 9. Treatment on page 253. Mentioned on page 250, 251, 252.

Plants tufted to matted, ± grayish green. Stems ascending to erect, (0.5–) 2–6 (–7) dm, hairs spreading. Basal leaves ± planar, (3–) 6–20 (–32) × 0.5–1.5 (–2) cm; stipules entire; leaflets 7–16 per side, separate to ± overlapping especially distally, broadly cuneate to nearly round, (3–) 4–15 (–17) × (2–) 5–12 mm, 3/4 to nearly as wide as long, divided 1/5–1/2 to midrib into (3–) 8–15 (–30) acute to obtuse teeth, often medially notched as well 1/3–2/3 to midrib, villous. Cauline leaves 3–5. Inflorescences open, flowers arranged individually and in glomerules. Pedicels 1–7 (–20) mm. Flowers 8–12 mm diam.; epicalyx bractlets lanceolate to ovate, 1.5–4.5 × 1–2 (–2.5) mm, 1/2–3/4 length of sepals, entire; hypanthium 1.5–3 × 3–6.5 mm, less than 1/2 as deep as wide, interior sparsely pilose; sepals spreading to ± reflexed, lanceolate, (3–) 4–6.5 mm; petals broadly oblanceolate-elliptic, 3–5.5 × 2–3 mm, apex truncate; filaments 1–2 × 0.5–1 mm, anthers 0.8–1.2 mm; carpels 20–60; styles 2.5–3 mm. Achenes brown, 1.5 mm, smooth.


Phenology: Flowering summer.
Habitat: Granitic sand, meadows, along stream banks, in chaparral, conifer woodlands
Elevation: 300–1900 m

Discussion

Of conservation concern.

Horkelia yadonii is known only from localized populations in the La Panza, San Rafael, and Santa Lucia ranges of Monterey, San Luis Obispo, and Santa Barbara counties. The isolated populations often differ in such characters as general size, leaf proportions, and shape of epicalyx bractlets. The most distinctive extreme, in Monterey County, is characterized by relatively long, narrow leaves, small, few-toothed leaflets, long pedicels, few small flowers, and ovate bractlets. These differences, however, are not consistently or sharply defined.

Selected References

None.

Lower Taxa

None.

"/2lengthofsepals" 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 yadonii"
rugose +  and smooth +
longer than wide +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Barbara Ertter +  and James L. Reveal +
Ertter +
compound +  and simple +
opposite +  and alternate +
20 cm200 mm <br />0.2 m <br /> (32 cm320 mm <br />0.32 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
6 cm60 mm <br />0.06 m <br /> (20 cm200 mm <br />0.2 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
flattened +
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 />) +
reduced +
free +  and distinct +
Yadon’s or Santa Lucia horkelia +
open to congested +
not +  and aggregated +
300–1900 m +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
lanceolate +  and ovate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
flattened +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.8 cm8 mm <br />0.008 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 />) +
Granitic sand, meadows, along stream banks, in chaparral, conifer woodlands +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
glabrous +  and pilose +
0 +  and 1/2 +
0.1 cm1 mm <br />0.001 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
crassinucellate +
opposite +  and alternate +
marcescent +
winter-persistent +
separate +  and more or less overlapping +
1.5 cm15 mm <br />0.015 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
notched +, divided +, broadly cuneate +  and nearly round +
0.5 cm5 mm <br />0.005 m <br /> (?) +  and 1.2 cm12 mm <br />0.012 m <br /> (?) +
oblanceolate +
palmate +  and pinnate +
shallowly toothed +  and deeply divided +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0.7 cm7 mm <br />0.007 m <br /> (2 cm20 mm <br />0.02 m <br />) +
recurved +  and reflexed +
0.1 cm1 mm <br />0.001 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
oblanceolate-elliptic +
0 (?) +  and 4 (?) +
free +  and distinct +
0.3 cm3 mm <br />0.003 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 />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
not arillate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
persistent +
free +  and distinct +
spreading +  and more or less reflexed +
lanceolate +
0.4 cm4 mm <br />0.004 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
Conservation concern +  and Endemic +
free +  and distinct +
branched +  and simple +
stramineous +, reddish +  and green +
ascending +  and erect +
1 +  and 10 +
palmate +  and pinnate +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Californicae +, Horkelia sect. Californicae +, Cuneatae +, Horkelia sect. Cuneatae +, Tenuilobae +  and Horkelia sect. Tenuilobae +
Horkelia yadonii +
Horkelia sect. Horkelia +
species +
8 +  and 15 +
acute +  and obtuse +
inconspicuous +
enlarged +
plant +  and matted +
hairy +  and inconspicuously conspicuously glandular +