Ivesia cryptocaulis
Ivesia sericoleuca
Charleston Peak ivesia, Charleston Peak mousetail
Plumas ivesia, Plumas mousetail
prostrate to decumbent, 0.2–0.6(–1) dm.
decumbent to ascending, 1.5–4.5 dm.
tightly cylindric, 1–4(–5) cm; sheathing base mostly not strigose abaxially;
petiole 0.3–2 cm, hairs 0.5–1 mm;
lateral leaflets 5–10(–12) per side, ± overlapping, ± flabellate, 1–2.5 mm, incised to base or nearly so into 3–5 obovate to oval lobes, apex sometimes ± setose, surfaces loosely long-strigose, sparsely 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.
1(–2);
blade vestigial.
3–8(–10).
1–10-flowered, ± congested, 0.5–1.5 cm diam.
20–120-flowered, (2–)4–14 cm diam., flowers mostly arranged in several to many tight glomerules of 5–10 flowers.
3–7(–10) mm.
1–3(–12) mm.
6–9 mm diam.;
epicalyx bractlets 5, lanceolate to narrowly oblong or narrowly ovate, 0.8–1.3 mm;
hypanthium shallowly cupulate, ± 1 × 2–3(–4) mm;
sepals 1.5–2.3 mm, ± acute;
petals yellow, oblanceolate to spatulate, 2–3.2 mm;
stamens 5, filaments 0.9–1.2 mm, anthers yellow, oblong, 0.7–0.9 mm;
carpels 6–10, styles 1–1.5 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, 1.4–1.8(–2) mm, smooth, not carunculate.
brown, 2–3 mm.
= 28.
Ivesia cryptocaulis
Ivesia sericoleuca
Of conservation concern.
Ivesia cryptocaulis is known only from timberline and above in the Spring Mountains of Clark County. Plants differ from all others of the genus by having slender, elongate, diffuse caudex branches that ramify through its habitat of gravel, scree, and talus. The species is here provisionally included in sect. Setosae as a diffusely matted relative of I. shockleyi (as also suggested by D. D. Keck 1938); the ecarunculate seeds and relatively straight pedicels may indicate a greater similarity to I. pygmaea in sect. Ivesia.
(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.)
CalFlora
WildflowerSearch
iNaturalist
USDA Plants Database
