Ivesia rhypara var. rhypara
Ivesia rhypara
grimy mousetail
grimy ivesia, grimy mousetail
(0.3–)0.4–1.5(–2) dm, usually exceeding leaves by more than 2 cm.
± prostrate, (0.1–)0.2–1.5(–2) dm.
tightly cylindric, 2–10 cm; sheathing base densely hairy abaxially;
petiole 0.5–4(–10) cm;
lateral leaflets 4–10(–15) per side, overlapping at least distally, ± flabellate, 0.5–3(–4) mm, incised to base or nearly so into (0–)2–4(–9) elliptic to obovate or orbiculate lobes, apex usually not setose, surfaces densely hirsute, cryptically glandular;
terminal leaflets indistinct.
(0–)1;
blade vestigial.
10–60(–100)-flowered, (1–)2–5(–7) cm diam.
5–60(–100)-flowered, congested, 0.5–5(–7) cm diam.
1.5–4(–8) mm.
4–8 mm diam.;
epicalyx bractlets 5, linear to elliptic or narrowly ovate, 0.8–1.6(–2.1) mm;
hypanthium patelliform to shallowly cupulate, 1–1.5 × (1.5–)2–3(–3.5) mm;
sepals 1.4–2.5(–2.8) mm, acute;
petals white to pale yellowish, linear to narrowly oblanceolate, 1–1.5 mm;
stamens 5, filaments 0.6–1.8 mm, anthers maroon or yellow with maroon margins, oblong, 0.3–0.6 mm;
carpels 1–2(–4), styles 1–1.5 mm.
brown, 1.2–1.6(–2) mm, smooth, prominently carunculate.
Ivesia rhypara var. rhypara
Ivesia rhypara
Of conservation concern.
Variety rhypara is known from widely scattered locations in central Malheur and southeastern Lake counties, Oregon, and in northern Washoe, Humboldt, and Elko counties, Nevada. Although not overtly petrophytic, plants are generally associated with crevices in the underlying bedrock (E. M. Clark and W. H. Clark 2003). They might thereby benefit from a more favorable water relationship, allowing them to be in full bloom when most associated species are summer-dormant.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
Ivesia rhypara forms densely hairy mats or mounds on isolated edaphic sites in the northern Great Basin. Only one of the widely disjunct population clusters is recognized as a distinct variety; the others have general differences in gestalt, but no significant distinctions have been determined (B. Ertter 1989). Isozyme analysis likewise does not show significant differences (T. Kaye et al., unpubl., BLM and Oregon Dept. of Agriculture, 1991). Reproductive studies by D. Wiens (pers. comm.) show low seed set (ca. 5% in var. rhypara, somewhat higher in var. shellyi), possibly indicating a deleterious genetic load.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants (4–)8–30 cm diam.; inflorescences (1–)2–5(–7) cm diam.; scarcely or cryptically petrophytic in bedrock overlain by rubble and soil. | var. rhypara |
1. Plants 2–10(–15) cm diam.; inflorescences 0.5–2(–5) cm diam.; overtly petrophytic in boulders and outcrops. | var. shellyi |
OR
CalFlora
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
