Ivesia rhypara

Ertter & Reveal

Madroño 24: 224, fig. 1. 1977.

Conservation concernEndemic
Treatment appears in FNA Volume 9. Treatment on page 228. Mentioned on page 220, 221, 223, 229.

Plants grayish, ± matted. Stems ± prostrate, (0.1–) 0.2–1.5 (–2) dm. Basal leaves 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. Cauline leaves (0–) 1; blade vestigial. Inflorescences 5–60 (–100) -flowered, congested, 0.5–5 (–7) cm diam. Pedicels 1.5–4 (–8) mm. Flowers 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. Achenes brown, 1.2–1.6 (–2) mm, smooth, prominently carunculate.

Discussion

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.

Selected References

None.

Key

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. Ivesia rhypara var. rhypara
1 Plants 2–10(–15) cm diam.; inflorescences 0.5–2(–5) cm diam.; overtly petrophytic in boulders and outcrops. Ivesia rhypara var. shellyi

"dm" is not declared as a valid unit of measurement for this property.

... more about "Ivesia rhypara"
0.16 cm1.6 mm <br />0.0016 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
1.2mm +  and 1.6mm +
yellow +  and maroon +
shorter than wide +  and longer +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Barbara Ertter +  and James L. Reveal +
Ertter & Reveal +
compound +  and simple +
opposite +  and alternate +
2 cm20 mm <br />0.02 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Setosae +
20 cm200 mm <br />0.2 m <br /> (25 cm250 mm <br />0.25 m <br />) +
narrowly oblong +  and filiform planar +
0.5 cm5 mm <br />0.005 m <br /> (20 cm200 mm <br />0.2 m <br />) +
reduced +
elongate +
free +  and distinct +
branched +  and simple +
Nev. +  and Oreg. +
not +  and aggregated +
linear +  and elliptic +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
deciduous +
obliquely ovoid +  and reniform +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
loose +  and capitate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
5-60(-100)-flowered +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
crassinucellate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
opposite +  and alternate +
winter-marcescent +
deciduous +  and persistent +
separate +  and overlapping +
, +  and distinct +
distinguishable +
lobed +  and toothed +
orbiculate +, obovate +  and elliptic +
verticillate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0 (?) +  and 4 (?) +
free +  and distinct +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (4 cm40 mm <br />0.04 m <br />) +
adnate +, free +, connate +  and distinct +
not arillate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Conservation concern +  and Endemic +
free +  and distinct +
branched +  and simple +
reddish +, grayish +  and green +
pendent +  and erect +
2 +  and 20 +
palmate +  and pinnate +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Saxosae +, Ivesia sect. Saxosae +, Potentilla sect. Saxosae +, Potentilla subg. Purpusia +  and Undefined sect. Purpusia +
not fusiform +
Ivesia rhypara +
Ivesia sect. Setosae +
species +
inconspicuous +
stipelike +, elongate +, less flat +  and conic or turbinate +
enlarged +
plant +  and matted +
glabrate +  and sparsely densely glandular-puberulent +