Ivesia setosa
Ivesia kingii
bristly ivesia
Ash Meadows ivesia, King's ivesia, King's mousetail
± ascending to nearly erect, 0.7–2.5(–2.8) dm.
usually prostrate-decumbent to ascending, sometimes ± erect, 1–4(–5.5) dm.
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.
5–20 cm; sheathing base glabrous or densely strigose abaxially;
stipules absent or linear to lanceolate, 1–4 mm;
petiole 0.2–1.2 cm, hairs absent or sparse to dense, appressed or ascending, 0.5–2 mm;
leaflets 15–60 per side, loosely to tightly overlapping, (1.8–)2–6(–8) mm, lobes (0–)2–4, narrowly oblanceolate to obovate, hairs absent or sparse to dense, ± appressed, 0.2–0.5(–1) mm.
(0–)1;
blade vestigial.
4–15.
(1–)5–15(–30)-flowered, ± open, 1–6(–12) cm diam.
5–100-flowered, 1–12 cm diam., flowers arranged individually and/or in few to several loose glomerules of 2–10 flowers.
5–15(–20) mm.
(1–)2–20(–25) 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.
8–12 mm diam.;
epicalyx bractlets lanceolate to elliptic or ovate, (0.8–)1–2(–2.5) mm;
hypanthium shallowly cupulate, 0.5–2 × 1.5–4 mm, ± 1/2 as deep as wide;
sepals sometimes purple-suffused, 2–4(–5) mm, narrowly acute to acuminate;
petals white, spatulate or obovate to orbiculate, (2.8–)3–5(–6) mm;
stamens 20, filaments filiform, 1.5–2.5 mm, anthers white to cream, 0.3–0.6 mm;
carpels 2–9, styles 2–2.5(–3) mm.
greenish white to light tan, 1.7–2 mm, smooth, ± carunculate.
light brown, 1.8–2.5 mm.
Ivesia setosa
Ivesia kingii
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.)
Varieties 2 (2 in the flora).
Significant variation in habit, indument, leaflet lobing, and compactness of inflorescence can be found among and within populations of Ivesia kingii; no taxonomic structure has yet been discerned beyond the varieties recognized here. The variation within widespread var. kingii suggests that var. eremica resulted from a southward, late Pleistocene migration of a hairy phase of I. kingii with compact leaflets out of the Great Basin onto the northern edge of the Mojave Desert (J. L. Reveal 1980). Although densely hairy plants are encountered widely in the Great Basin, only in the Ash Meadows area of southernmost Nye County, the home of var. eremica, is there a consistently hairy phase. The leaflets of var. eremica are so tightly compacted that individual leaflets cannot be distinguished; in var. kingii, leaflets are individually distinct, though plants from Mineral County sometimes approach var. eremica in this regard. In the field, shoots of var. kingii arise directly from a taproot with the spreading branches flowing outwardly from a single point of attachment. In var. eremica, older, mature plants form compact mats with short, spreading caudex branches.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaflets individually ± distinguishable, loosely to tightly overlapping; caudices simple or few branched; Great Basin, ec California, Nevada, w Utah. | var. kingii |
1. Leaflets mostly not individually distinguishable, tightly overlapping; caudices often much branched; n Mojave Desert, Nevada. | var. eremica |
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