Ivesia shockleyi
Ivesia sericoleuca
Shockley's ivesia, sky mousetail
Plumas ivesia, Plumas mousetail
prostrate to ascending, 0.2–1.5 dm.
decumbent to ascending, 1.5–4.5 dm.
tightly to loosely cylindric, (1–)2–12(–14) cm; sheathing base strigose to hirsute abaxially;
petiole 0.5–4 cm;
lateral leaflets (3–)5–15(–18) per side, separate to overlapping at least distally, ± flabellate, 1–4(–6) mm, incised to base or nearly so into 2–10(–12) oblanceolate to obovate or elliptic lobes, apex sometimes setose, surfaces ± sparsely hirsute, ± glandular;
terminal leaflets indistinct.
10–20(–30) cm; sheathing base densely strigose abaxially;
stipules absent;
petiole 2–6(–10) cm, hairs abundant, usually spreading, 1–4 mm;
leaflets 20–35 per side, loosely overlapping, 3–15 mm, lobes 0–4, oblanceolate to elliptic, hairs abundant, spreading to ascending, (0.5–)1–3(–4) mm.
(0–)1;
blade vestigial or reduced.
3–8(–10).
2–20-flowered, ± open, 0.5–4(–6) cm diam.
20–120-flowered, (2–)4–14 cm diam., flowers mostly arranged in several to many tight glomerules of 5–10 flowers.
3–10(–12) mm.
1–3(–12) mm.
5–10 mm diam.;
epicalyx bractlets 5, elliptic or narrowly oblong to ovate, 0.7–2(–3) mm;
hypanthium patelliform, 1–2 × 2.5–4.5(–5) mm;
sepals 1.5–3.5(–4) mm, acute to obtuse;
petals ± yellow, oblanceolate to spatulate or narrowly obovate, 1–3 mm;
stamens 5, filaments 0.8–1.8 mm, anthers yellow, oblong, 0.4–0.9 mm;
carpels 2–5(–6), styles 1.8–2.5 mm.
10–15 mm diam.;
epicalyx bractlets narrowly lanceolate to narrowly elliptic, (1.5–)2–2.5(–3) mm;
hypanthium campanulate to shallowly turbinate, 1.5–3 × 2.5–4.5(–5) mm, often nearly as deep as wide;
sepals sometimes purple-suffused, 3–5.5 mm, acute to acuminate;
petals white, broadly spatulate to broadly obovate or obcordate, 4–7 mm;
stamens 20, filaments filiform, 1.5–3 mm, anthers white to cream, 0.5–0.7 mm;
carpels 2–7, styles 2.5–4 mm.
greenish cream to light brown, 1.5–2.2(–2.5) mm, smooth, prominently carunculate.
brown, 2–3 mm.
= 28.
Ivesia shockleyi
Ivesia sericoleuca
Varieties 2 (2 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Ivesia sericoleuca is known from valleys and flats in the northern Sierra Nevada. Many historic collections were identified and distributed as I. unguiculata, and circumscriptions prior to 1962 include I. aperta (hence reports from Nevada).
Hairs are usually dense in plants of Ivesia sericoleuca, such that the leaves, and occasionally the stems and branches, are silvery gray, especially in Sierra Valley and the Feather River drainage. Plants in the Truckee River drainage tend to be less hairy with redder stems, less glomerate inflorescences, shallower hypanthia, and more conspicuous glandularity.
As mentioned by J. T. Howell (1962), the chromosome count given for Ivesia sericoleuca by P. A. Munz (1959) most likely was based on a collection of I. aperta var. aperta. The chromosome count given here is instead based on Kruckeberg 3665, originally distributed as I. pickeringii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lateral leaflets: lobes 2–5(–7); inflorescences 2–10-flowered, 0.5–3 cm diam.; e California, c, se Oregon, c, n Nevada. | var. shockleyi |
1. Lateral leaflets: lobes (4–)6–10(–12); inflorescences 5–20-flowered, (1–)3–4(–6) cm diam.; wc Utah. | var. ostleri |
OR
CalFlora
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
