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Lyall's saxifrage, red-stem saxifrage

large-petal saxifrage, razshivin's saxifrage

mountain saxifrage, redwool saxifrage, western mountain saxifrage, western saxifrage

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

basal;

petiole rounded to flattened, 2–10 cm;

blade spatulate to obovate, 0.8–8 cm, thin, base cuneate to slightly attenuate, margins serrate to dentate, eciliate or sparsely glandular-ciliate, surfaces abaxially glabrous, adaxially sparsely brown-hairy.

basal;

petiole ± distinct to indistinct, flattened, (0.3–)0.5–3 cm;

blade oblanceolate to narrowly oblanceolate or narrowly spatulate, sometimes ± narrowly obovate, (0.5–)0.9–3.5 cm, ± fleshy, base ± attenuate to cuneate, margins (3–)5–7(–9)-toothed in distal 1/2 (teeth 0.5 mm), sparsely ciliate, surfaces glabrous.

basal;

petiole flattened, 1–5 cm;

blade ovate to elliptic, 1.5–3.5 cm, ± fleshy, base ± attenuate to ± truncate, margins shallowly, sharply serrate, ciliate, surfaces sparsely tangled, reddish brown-hairy abaxially, glabrous adaxially.

Inflorescences

usually 10–15-flowered, lax, cylindric thyrses, (red), (4–)7–30 cm, sparsely purple-tipped stipitate-glandular.

(2–)4–16-flowered, open, racemiform, sometimes paniculiform thyrses, sometimes solitary flowers, 3–15.5(–17 in fruit) cm, glabrous; (bracts reduced).

usually (10–)30+-flowered, flowers crowded into 1+ glomerules in thyrses with ascending branches, 8–30 cm, purple-tipped stipitate-glandular; (bracts glabrous or marginally glandular-ciliate).

Flowers

sepals reflexed, oblong to elliptic;

petals white, each with 2 basal yellowish green spots, elliptic to round, clawed, 2–5.5 mm, longer than sepals;

filaments club-shaped, (to 6 mm);

pistils connate 1/2+ their lengths;

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

sepals reflexed, oblong or lanceolate to ovate;

petals white to cream, often purplish, not spotted, linear to ± narrowly elliptic, not clawed, 2–4 mm, usually longer to sometimes shorter than sepals;

filaments linear, flattened;

pistils connate 1/2+ their lengths, (conic);

ovary ± 1/2 inferior.

sepals ascending to spreading, sometimes reflexed in fruit, ovate to oblong, (surfaces glabrous);

petals white, not spotted (spots rarely present), obovate to almost round, clawed, 2–4 mm, to 1.5 times as long as sepals;

filaments linear to very slightly widened near anthers, flattened;

pistils distinct almost to base;

ovary ± superior.

Capsules

green to yellow, distal 1/2 purple, ± folliclelike, (basally connate).

dark purple-black, valvate.

greenish or reddish to ± dark purple, folliclelike.

2n

= ca. 56, 58.

= 20, 38, 40, 56, 58.

Micranthes lyallii

Micranthes razshivinii

Micranthes occidentalis

Phenology Flowering summer–early autumn. Flowering summer. Flowering spring–summer.
Habitat Wet, rocky meadows, mountain to alpine streamsides Tundra, stream banks, alpine rocky slopes Wet, rocky or gravelly slopes, moist to dry alpine meadows, flushes
Elevation 800-4000 m [2600-13100 ft] 400-2000 m [1300-6600 ft] 500-4000 m [1600-13100 ft]
Distribution
from FNA
AK; ID; MT; WA; AB; BC; NT; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; NT; YT
[BONAP county map]
from FNA
AK; ID; MT; NV; OR; SD; WA; WY; AB; BC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Although they have nearly disjunct sets of populations, the subspecies of Micranthes lyallii are difficult to distinguish from each other. The more northern plants tend to be larger with wider leaves and often have been called Saxifraga lyallii subsp. or var. hultenii. Apparent hybrids with M. odontoloma occur in Alberta, British Columbia, and northern Idaho, and near Glacier National Park, Montana.

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

Micranthes razshivinii is found in eastern Alaska (eastern Brooks Range, from Atigun Pass eastward and from Mount McKinley National Park eastward) into Yukon and in the Mackenzie and Richardson mountains in the Northwest Territories. Its leaves are generally narrower than those of M. calycina and the teeth are less numerous. The glabrous inflorescence branches of M. razshivinii readily distinguish it from M. calycina, which has hairy branches. The ranges of the two species may overlap or at least abut in the Atigun Pass area of the Brooks Range, in the Mount McKinley National Park area, and possibly in the Saint Elias Mountains. Hybrids would be very difficult to distinguish from the parents but may occur. They have not been observed in the material examined. Plants of this species sometimes have been misidentified as M. davurica (Willdenow) Small, a species restricted to eastern Siberia.

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

Micranthes occidentalis appears closely related to the little-known M. mexicana (Engler & Irmscher) Brouillet & Gornall from Chihuahua, Mexico. The latter is the only species of the genus that occurs in Mexico and not in the United States. Micranthes occidentalis is disjunct between the northern Rocky Mountains and the Cypress Hills of southeastern Alberta and southwestern Saskatchewan, and the Black Hills of South Dakota. It hybridizes with M. idahoensis where their ranges overlap.

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

Source FNA vol. 8, p. 57. FNA vol. 8, p. 59. FNA vol. 8, p. 62.
Parent taxa Saxifragaceae > Micranthes 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. idahoensis, M. integrifolia, 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. gormanii, 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. 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. gormanii, 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. 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 lyallii, Saxifraga lyallii subsp. hultenii, Saxifraga lyallii var. hultenii Saxifraga razshivinii Saxifraga occidentalis, Saxifraga allenii, Saxifraga occidentalis var. allenii, Saxifraga occidentalis var. wallowensis, Saxifraga reflexa subsp. occidentalis, Saxifraga saximontana
Name authority (Engler) Small: in N. L. Britton et al., N. Amer. Fl. 22: 143. 1905 , (Zhmylev) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1021. (2007) (S. Watson) Small: in N. L. Britton et al., N. Amer. Fl. 22: 144. 1905 ,
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