Ivesia gordonii
Ivesia argyrocoma
alpine ivesia, alpine mousetail, Gordon's ivesia
silver-hair ivesia, silverhair mousetail
prostrate to erect, (0.2–)0.5–4 dm.
tightly to loosely cylindric, (1–)3–20(–25) cm; sheathing base ± glandular abaxially, otherwise glabrous;
petiole 0.5–8 cm, hairs 0.2–0.5 mm;
leaflets (6–)10–25 per side, (1–)2–13(–18) mm, glabrous or ± hirsute or villous, glandular-puberulent or -pubescent, lobes (2–)4–8(–15), linear or narrowly oblanceolate to obovate, apex rarely setose.
1(–2), not paired.
5–50(–70)-flowered, 1–8(–11) cm diam.;
glomerules 1–several.
1–3(–5) mm.
5–12 mm diam.;
epicalyx bractlets linear to narrowly elliptic, (0.5–)1–3.5(–4) mm;
hypanthium turbinate to campanulate, (1.5–)2–4(–4.5) × 2–4(–5) mm;
sepals (2–)2.5–5(–6) mm, obtuse to ± acute;
petals yellow, narrowly oblanceolate to narrowly spatulate, (1–)1.5–3 mm;
stamens 5, filaments 1.3–2.5 mm, anthers yellow, sometimes red-margined, 0.5–1 mm;
carpels (1–)2–4(–6), styles 2.5–4.5(–6) mm.
grayish brown to mottled brown, ± 2 mm.
Ivesia gordonii
Ivesia argyrocoma
Varieties 4 (4 in the flora).
Ivesia gordonii is the most widespread species of the genus, occurring from Washington to Montana, south to central California and Colorado. The species can be distinguished from other members of sect. Ivesia by the relatively deep hypanthium, which is about as deep as wide. Four varieties are provisionally recognized here (B. Ertter and J. L. Reveal 2007), with the likelihood that future work may indicate additional and/or alternate circumscriptions. Populations that are difficult to assign to a variety can be found where the recognizable taxonomic units come together, for example, in northeastern Utah and western Wyoming, involving var. gordonii and var. wasatchensis, and in California and central Idaho where var. alpicola and var. ursinorum tend to merge.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (1 in the flora).
Plants from the central Sierra San Pedro Mártir in northern Baja California belong to var. moranii Ertter & Reveal, which may be distinguished by its compact stature (to 0.5 dm), densely villous basal stipules 2–4 mm, decumbent stems 2–7 cm that are stipitate-glandular under the villous indumentum, and solitary, loosely congested cyme. The petals are oblanceolate to narrowly obovate and 2.5–3.5 mm. The grayish, faintly mottled achenes are 1.3–2 mm.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaflets 7–13(–18) mm, glabrous or sparsely hirsute or villous marginally; stems (1–)1.5–4 dm; inflorescences usually branched, 2–8(–11) cm diam., glomerules (1–)2–6(–10), ± capitate. | var. wasatchensis |
1. Leaflets (1–)2–7(–9) mm, hairy or ± glabrous except marginally ciliate; stems (0.2–)0.5–2.5 dm; inflorescences simple or branched, 1–3(–5) cm diam., glomerules 1(–3), ± capitate to loosely congested | → 2 |
2. Stems usually prostrate to ascending, rarely nearly erect, usually dark reddish, minutely glandular or glandular-puberulent to -pubescent; leaves to 0.8 cm diam.; anthers usually red-margined. | var. ursinorum |
2. Stems usually ascending to erect, sometimes decumbent, usually greenish, rarely reddish, hirsute to villous, glandular-puberulent to -pubescent; leaves to 1.5 cm diam.; anthers rarely red-margined | → 3 |
3. Stems usually hirsute to villous, sometimes densely so, glandular-pubescent or eglandular; basal leaves (3–)5–10(–15) cm; flowers 7–12 mm diam.; e Idaho and w Montana to Utah, Wyoming, and w Colorado. | var. gordonii |
3. Stems not or sparsely hirsute to villous, glandular-puberulent or -pubescent; basal leaves 2–8(–10) cm; flowers 5–9 mm diam.; s Washington to California and e to w Montana. | var. alpicola |
CA
OR
WA
Flora NW
PNW Herbaria
SW CO Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
