Ivesia muirii
Ivesia aperta
granite mousetail, Muir's ivesia
Sierra Valley ivesia, Sierra Valley mousetail
usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm.
decumbent to erect, 1.5–4.5 dm.
very tightly cylindric (mousetail-like, with individual leaflets scarcely distinguishable), 2–5(–10) cm; sheathing base densely strigose abaxially;
petiole 0.2–0.8(–1) cm, hairs 0.5–1.5 mm;
leaflets 25–40 per side, 0.4–1 mm, densely sericeous, glands obscured, lobes 2–5, obovate or oval to orbiculate, apex not setose.
(7–)10–20(–23) cm; sheathing base densely strigose abaxially;
stipules absent;
petiole 4–8 cm, hairs abundant, ascending, ± 1(–3) mm;
leaflets 20–35 per side, loosely overlapping, 3–15(–20) mm, lobes 0–4(–5), oblanceolate to elliptic, hairs abundant, ascending to appressed, ± 1(–2) mm.
(0–)1–2, paired if 2.
3–8.
10–30-flowered, 1–2(–3.5) cm diam.;
glomerules usually 1.
(10–)20–250-flowered, 1–14 cm diam., flowers arranged in several to many tight glomerules of 5–20 flowers.
0.3–2(–3.5) mm.
1–3(–15) mm.
5–6 mm diam.;
epicalyx bractlets oblong to obovate, 0.5–1 mm;
hypanthium shallowly cupulate, 0.5–1(–1.5) × 1.5–2.5 mm;
sepals (1–)1.5–2.5 mm, acute;
petals yellow, linear to oblanceolate or narrowly oblong, 1–2 mm;
stamens 5, filaments 0.3–0.6 mm, anthers yellow, 0.4–0.6 mm;
carpels 1–4, styles 0.7–1.2 mm.
5–12 mm diam.;
epicalyx bractlets lanceolate, 1.5–2.5(–3.5) mm;
hypanthium cupulate, 1–2 × 2.5–4(–5) mm, 1/2–2/3 as deep as wide;
sepals green, 2.5–4(–5.5) mm, acute to acuminate;
petals light yellow, oblanceolate to broadly obovate, 2–7 mm;
stamens 20, filaments filiform, 1–4 mm, anthers yellow, 0.4–0.6 mm;
carpels 2–7, styles 2–4 mm.
grayish brown, mottled with red, 1.6–2 mm.
brown, 2–3 mm.
Ivesia muirii
Ivesia aperta
Ivesia muirii is known from alpine areas in the Sierra Nevada. It is one of the more distinctive species of the genus, in its silvery mousetail-like leaves and usually tightly capitate inflorescences. Putative hybrids are known with I. lycopodioides (D. D. Keck 1938) and I. pygmaea (Center Basin area of Tulare County).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
Many historic collections of Ivesia aperta were identified as I. pickeringii. D. D. Keck (1938) considered I. aperta to be no more than a yellow-flowered form of I. sericoleuca, a situation clarified and rectified by J. T. Howell (1962). The ranges of the two species overlap in Sierra Valley, California, with mixed populations occurring near Beckwourth and in the valleys north of Sierra Valley. In general, var. aperta occurs in the southeastern portions of the valley and I. sericoleuca occurs on the western side; the species are not otherwise sympatric. In addition to petal color, which fades in herbarium material, I. aperta differs from I. sericoleuca in having smaller flowers with shallower hypanthia. Hairs at the base of the stems and petioles of I. aperta are relatively short (to 2 mm) and generally ascending; those of I. sericoleuca are longer (to 4 mm) and spreading. Variety canina combines the petal color of var. aperta and floral dimensions of I. sericoleuca.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Petals 2–3 mm, oblanceolate; filaments 1–1.5(–2) mm; Sierra Valley drainage, California, Carson and Virginia ranges, Nevada. | var. aperta |
1. Petals usually 4–7 mm, narrowly to broadly obovate; filaments 2–4 mm; Dog Valley, California, Nevada. | var. canina |
CA
WildflowerSearch
iNaturalist
USDA Plants Database
