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Idaho saxifrage

Gorman's saxifrage

Habit Plants solitary or tufted, with bulbils on caudices. Plants in groups or, sometimes, almost mat-forming, rhizomatous.
Leaves

basal;

petiole flattened, 1–5 cm;

blade ovate to elliptic, 1–4 cm, ± fleshy, base attenuate, margins shallowly serrate to dentate (teeth usually to 1 mm), sparsely ciliate, surfaces tangled, reddish brown-hairy abaxially, glabrate adaxially.

basal;

petiole flattened, 5–7.5 cm;

blade ovate to elliptic, 3–4 cm, fleshy, base attenuate, margins shallowly crenate-serrate, sparsely ciliate, surfaces tangled, reddish brown-hairy.

Inflorescences

15+-flowered, open thyrses, (flowers ± crowded at tips, becoming more open in fruit), 10–40 cm, purple-tipped stipitate-glandular.

(10–)30+-flowered, open, lax, strongly divaricately branched, conic thyrses, 8–30 cm, purple-tipped stipitate-glandular; (bracts glabrous, proximal marginally ciliate).

Flowers

sepals reflexed, ovate to oblong;

petals white, with 2 basal yellow spots (often faded when dried), elliptic to ovate, clawed to nearly not clawed, 1–3.5 mm, ± equaling sepals;

filaments club-shaped, not petaloid, (equaling petals);

pistils distinct almost to base;

ovary superior, (to 1/3 adnate to hypanthium).

sepals ascending, ovate to oblong, (margins eciliate, surfaces glabrous);

petals white, not spotted, obovate to ± round, clawed, ca. 2 mm, ca. 1.5 times as long as sepals;

filaments linear, flattened;

pistils distinct almost to base;

ovary nearly 1/3 inferior, (to 1/3 adnate to hypanthium).

Capsules

green to reddish purple, folliclelike.

greenish to reddish purple, folliclelike.

2n

= 20.

= 20, 38, 40.

Micranthes idahoensis

Micranthes gormanii

Phenology Flowering spring–early summer. Flowering spring.
Habitat Open ledges and slopes Wet, rocky ledges and slopes
Elevation 500-2500 m (1600-8200 ft) 0-1000 m (0-3300 ft)
Distribution
from FNA
ID; MT; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
OR; WA
[WildflowerSearch map]
[BONAP county map]
Discussion

Micranthes idahoensis appears to hybridize with M. occidentalis where their ranges overlap. Intermediates are abundant in some populations along the Idaho-Montana border and in Montana. This phenomenon may explain the range of filament shapes found in M. occidentalis, from flattened to sightly club-shaped. The issue of the status of M. idahoensis with respect to M. marshallii (D. L. Krause and K. I. Beamish 1972) is best deferred until a thorough study of the whole complex over its entire range is done.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 8, p. 64. FNA vol. 8, p. 62.
Parent taxa Saxifragaceae > Micranthes Saxifragaceae > Micranthes
Sibling taxa
M. apetala, M. aprica, M. bryophora, M. californica, M. calycina, M. careyana, M. caroliniana, M. eriophora, M. ferruginea, M. foliolosa, M. fragosa, M. gaspensis, M. gormanii, M. hieraciifolia, M. hitchcockiana, M. howellii, M. integrifolia, M. lyallii, M. marshallii, M. micranthidifolia, M. nelsoniana, M. nidifica, M. nivalis, M. nudicaulis, M. occidentalis, M. odontoloma, M. oregana, M. palmeri, M. pensylvanica, M. petiolaris, M. razshivinii, M. reflexa, M. rhomboidea, M. rufidula, M. spicata, M. stellaris, M. subapetala, M. tempestiva, M. tenuis, M. texana, M. tischii, M. tolmiei, M. unalaschcensis, M. virginiensis
M. apetala, M. aprica, M. bryophora, M. californica, M. calycina, M. careyana, M. caroliniana, M. eriophora, M. ferruginea, M. foliolosa, M. fragosa, M. gaspensis, M. hieraciifolia, M. hitchcockiana, M. howellii, M. idahoensis, M. integrifolia, M. lyallii, M. marshallii, M. micranthidifolia, M. nelsoniana, M. nidifica, M. nivalis, M. nudicaulis, M. occidentalis, M. odontoloma, M. oregana, M. palmeri, M. pensylvanica, M. petiolaris, M. razshivinii, M. reflexa, M. rhomboidea, M. rufidula, M. spicata, M. stellaris, M. subapetala, M. tempestiva, M. tenuis, M. texana, M. tischii, M. tolmiei, M. unalaschcensis, M. virginiensis
Synonyms Saxifraga idahoensis, Saxifraga marshallii subsp. idahoensis, Saxifraga marshallii var. idahoensis, Saxifraga occidentalis var. idahoensis Saxifraga gormanii, Saxifraga occidentalis var. dentata
Name authority (Piper) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1020. 2007 , (Suksdorf) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1020. 2007 ,
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