Ivesia webberi
Ivesia setosa
Webber's ivesia, wire ivesia, wire mousetail
bristly ivesia
decumbent to ascending, 0.5–1.5(–1.8) dm.
± ascending to nearly erect, 0.7–2.5(–2.8) dm.
loosely ± cylindric, 3–7(–10) cm; sheathing base ± strigose abaxially;
petiole 0.5–5(–6) cm, hairs 2–4 mm;
leaflets 4–8(–10) per side, (0.5–)3–8(–10) mm, loosely long-strigose or -villous and short-hirsute, ± glandular, lobes 2–5(–12), linear to lanceolate, apex not setose.
weakly planar to loosely cylindric, 5–9(–12) cm; sheathing base ± strigose abaxially;
petiole 1–8 cm;
lateral leaflets 5–10 per side, separate to overlapping distally, ± flabellate, 2–8 mm, incised ± 3/4 to base, sometimes nearly to base, into (3–)7–11 ovate teeth to narrowly obovate lobes, apex usually ± setose, surfaces ± sparsely hirsute, conspicuously glandular;
terminal leaflets ± indistinct.
2, paired.
(0–)1;
blade vestigial.
5–15(–25)-flowered, 1.5–3(–6) cm diam.;
glomerules 1.
(1–)5–15(–30)-flowered, ± open, 1–6(–12) cm diam.
(0.5–)1–8(–13) mm.
5–15(–20) mm.
9–12 mm diam.;
epicalyx bractlets linear, 1.2–3 mm;
hypanthium cupulate, 1–2(–2.5) × 2.5–5 mm;
sepals 2.5–4.5(–5.5) mm, acute;
petals yellow, narrowly oblanceolate, 2–3(–4) mm;
stamens 5, filaments 1.8–2.5(–3) mm, anthers yellow, (0.8–)1–1.6 mm;
carpels 3–8, styles 1.8–2.2 mm.
7–10 mm diam.;
epicalyx bractlets 5, lanceolate, 1.3–2.5(–3) mm;
hypanthium patelliform, (1–)1.5–2 × 2–3.5(–4) mm;
sepals (1.5–)2–3.5 mm, ± acute;
petals yellow, oblanceolate to narrowly spatulate, 1.5–2.5 mm;
stamens 5, filaments 0.8–1.5 mm, anthers yellow, oblong, 0.4–0.7 mm;
carpels 2–8, styles 1.2–2 mm.
light brown, often mottled darker brown, 1.9–2.5 mm.
greenish white to light tan, 1.7–2 mm, smooth, ± carunculate.
Ivesia webberi
Ivesia setosa
Of conservation concern.
Ivesia webberi is known only from the eastern foothills of the northern Sierra Nevada and scattered ranges to the east in California and adjacent Nevada. It is among the more distinctive species in the genus and is only tentatively placed in sect. Ivesia. The leaflets are loosely incised into slender, sparsely villous segments, and the two cauline leaves are paired with dissected stipules. Previous reports of the stems and inflorescence branches being glandular-puberulent are due to a misinterpretation of the minute pustulose bases associated with the villous indumentum as being enlarged glands.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Ivesia setosa occurs mostly to the east and south of I. baileyi, from southeastern Humboldt and Churchill counties to Elko, White Pine, and northern Nye counties, Nevada, and in the Deep Creek Range of western Utah. It represents a transition between the planar-leaved, chasmophytic members of sect. Setosae and the cylindric-leaved, matted species of flatter sites. Stems of I. setosa are more generally erect than in other species in the section, and the usually calcareous substrate is noteworthy. The deeply incised (usually not quite to base) leaflets are somewhat intermediate between the toothed leaflets of I. baileyi and the leaflets of I. shockleyi that are incised to the base into separate lobes. The individual leaflets of both I. baileyi and I. setosa are more or less flat and distichously paired; in I. shockleyi, groups of leaflet lobes are folded over onto each other, giving a verticillate appearance to the leaflet arrangement.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
