Ivesia pickeringii

Torrey ex A. Gray

Proc. Amer. Acad. Arts 6: 531. 1865.

Common names: Pickering’s ivesia
Conservation concernEndemic
Synonyms: Potentilla pickeringii (Torrey ex A. Gray) Greene
Treatment appears in FNA Volume 9. Treatment on page 239. Mentioned on page 238, 240.

Plants grayish green; glands abundant. Stems ascending to erect, 3–5 dm. Basal leaves 8–20 cm; sheathing base ± strigose abaxially; stipules linear to narrowly lanceolate, 3–5 mm; petiole 1–3.5 cm, hairs abundant, ascending to spreading, 1–2 mm; leaflets 35–50 per side, loosely overlapping, 2–6 mm, lobes 3–5, oblanceolate to obovate or oval, hairs abundant, ± ascending, 1–2 (–3) mm. Cauline leaves 5–10. Inflorescences 10–100-flowered, (1.5–) 5–15 cm diam., flowers usually arranged individually, sometimes more congested. Pedicels (1–) 2–10 mm. Flowers 8–13 mm diam.; epicalyx bractlets linear-lanceolate to lanceolate, (1.8–) 2–2.5 mm; hypanthium cupulate to turbinate, 1.5–3 × 2.5–4 mm, often nearly as deep as wide; sepals often purple-suffused or mottled, (2.5–) 3–5 mm, acuminate; petals white, becoming pink-tinged with age, oblanceolate to narrowly spatulate, (2.8–) 3–5 (–6) mm; stamens 20, filaments filiform, 1.5–2.3 mm, anthers white to cream, 0.3–0.6 mm; carpels 2–4, styles 2.5–3.5 mm. Achenes dark-brown, 2.5–3 mm.


Phenology: Flowering summer.
Habitat: Moist, rocky, grassy meadows, mainly on ultramafic-derived clayey soil, in montane conifer woodlands
Elevation: 800–1500 m

Discussion

Of conservation concern.

Ivesia pickeringii is known from Siskiyou and Trinity counties. Some early treatments (for example, P. A. Rydberg 1898, 1908–1918; W. L. Jepson [1923–1925], 1909–1943, vol. 2) conflated this species with I. aperta, hence reports of I. pickeringii in the Sierra Nevada. Historic collections from Edgewood, at the headwaters of the Shasta River in Siskiyou County, have inflorescences more glomerulate than elsewhere in the species range.

The chromosome count of 2n = 28 (P. A. Munz 1959) needs confirmation. If based on Kruckeberg 3665, which was distributed as a voucher for that count, the determination of this collection has been changed to Ivesia sericoleuca.

Selected References

None.

Lower Taxa

None.

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

... more about "Ivesia pickeringii"
not carunculate +
2.5mm +  and 3mm +
white +  and cream +
less as-long-as to longer than wide +  and more +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Barbara Ertter +  and James L. Reveal +
Torrey ex A. Gray +
compound +  and simple +
opposite +  and alternate +
8 cm80 mm <br />0.08 m <br /> (20 cm200 mm <br />0.2 m <br />) +
Unguiculatae +
20 cm200 mm <br />0.2 m <br /> (25 cm250 mm <br />0.25 m <br />) +
narrowly oblong +  and filiform planar +
0.5 cm5 mm <br />0.005 m <br /> (20 cm200 mm <br />0.2 m <br />) +
reduced +
elongate +
free +  and distinct +
branched +  and simple +
Pickering’s ivesia +
not +  and aggregated +
800–1500 m +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
linear-lanceolate +  and lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
deciduous +
obliquely ovoid +  and reniform +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
loose +  and capitate +
Moist, rocky, grassy meadows, mainly on ultramafic-derived clayey soil, in montane conifer woodlands +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
ascending +  and spreading +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
crassinucellate +
opposite +  and alternate +
winter-marcescent +
deciduous +  and persistent +
, +  and distinct +
not +  and distinguishable +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
oblanceolate +  and obovate or oval +
verticillate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0 (?) +  and 4 (?) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
free +  and distinct +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
Proc. Amer. Acad. Arts +
not arillate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
mottled +  and purple-suffused +
persistent +
free +  and distinct +
erect +  and spreading +
acuminate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Conservation concern +  and Endemic +
free +  and distinct +
branched +  and simple +
reddish +, grayish +  and green +
ascending +  and erect +
2 +  and 20 +
palmate +  and pinnate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Potentilla pickeringii +
Ivesia pickeringii +
Ivesia sect. Unguiculatae +
species +
glabrate +  and hairy +
inconspicuous +
stipelike +, elongate +, less flat +  and conic or turbinate +
enlarged +
tufted +  and rosetted +
glabrate +  and sparsely densely glandular-puberulent +