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Lyall's saxifrage, red-stem saxifrage

alpine saxifrage, Tolmie's alpine saxifrage, Tolmie's saxifrage

dotted saxifrage, heartleaf saxifrage

Habit Plants solitary or sometimes mat-forming, rhizomatous. Plants mat-forming, (stems trailing, thin, basally slightly woody), with slender, woody caudices. Plants solitary or tufted, with bulbils on branched caudices, 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.

cauline, proximally crowded;

petiole absent;

blade elliptic-obovate, 0.8–1.5 cm, fleshy, base cuneate, margins entire, sometimes proximally sparsely long-ciliate, surfaces glabrous.

basal;

petiole rounded, 3–30 cm;

blade reniform to round, 2–9 cm, thin or slightly fleshy, sometimes thick and fleshy, base cordate, margins deeply crenate, eciliate or sparsely short glandular-ciliate, surfaces glabrous or ± hairy.

Inflorescences

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

2–10-flowered, lax cymes, sometimes solitary flowers, 3–12 cm, glabrous or purplish- or pink-tipped stipitate-glandular; (bracts 1–3, proximal).

10+-flowered, ± open, lax to congested, conic, sometimes also glomerate thyrses, 10–35 cm, tangled-hairy (pilose-arachnoid) at least distally, sometimes also purple- or brown-tipped stipitate-glandular.

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 erect to spreading, ovate;

petals white, not spotted, linear to oblanceolate, 2.5–5 mm, longer than sepals, short- or not clawed;

filaments broadly club-shaped (± petaloid);

pistils connate to 1/2 their lengths;

ovary ± superior (to 1/4 adnate to hypanthium).

sepals reflexed, ± ovate;

petals white to pinkish, rarely orange-spotted, ovate to oblong, narrowly to broadly clawed, 2.5–4.5 mm, longer than sepals;

filaments distinctly club-shaped;

pistils connate 1/2–3/4 their lengths;

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

Capsules

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

green, purple mottled, valvate.

green to yellow and purplish tinged to dark purple, valvate.

2n

= ca. 56, 58.

= 30.

Micranthes lyallii

Micranthes tolmiei

Micranthes nelsoniana

Phenology Flowering summer–early autumn. Flowering summer.
Habitat Wet, rocky meadows, mountain to alpine streamsides Arctic and alpine tundra, fell-fields
Elevation 800-4000 m [2600-13100 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; CA; ID; MT; NV; OR; UT; WA; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; OR; WA; AB; BC; NT; NU; YT; Europe (ne Russia); Asia
[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.)

Unlike those of most Micranthes species, the leaves of M. tolmiei are proximally cauline and the ovules have two integuments. The seeds have a loose, winglike testa.

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

Varieties 6 (5 in the flora).

Although sometimes reported for North America, Saxifraga nelsoniana var. aestivalis (Fischer & C. A. Meyer) H. Ohba (S. aestivalis Fischer & C. A. Meyer) is found only in Eurasia.

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

Key
1. Inflorescences purple- or brown-tipped stipitate- glandular.
M. nelsoniana var. nelsoniana
1. Inflorescences tangled-hairy
→ 2
2. Leaf blade margins 9-12-toothed; capsules 6-12 mm; mostly Queen Charlotte Islands, adjacent coastal British Columbia.
M. nelsoniana var. carlottae
2. Leaf blade margins 12-18-toothed; capsules 3-8 mm; Oregon to Alaska and nw Canada
→ 3
3. Inflorescences somewhat lax, hairs appressed; Coast Ranges and Cascades, British Columbia, Oregon, Washington.
M. nelsoniana var. cascadensis
3. Inflorescences congested, hairs ascending; nw Canada, Alaska
→ 4
4. Leaf blades thick, fleshy; pistils connate most of their lengths; Aleutian Islands, Alaska.
M. nelsoniana var. insularis
4. Leaf blades thin, not fleshy; pistils connate to 3/4 their lengths; nw Canada, Alaska.
M. nelsoniana var. porsildiana
Source FNA vol. 8, p. 57. FNA vol. 8, p. 54. FNA vol. 8, p. 54.
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. razshivinii, M. reflexa, M. rhomboidea, M. rufidula, M. spicata, M. stellaris, M. subapetala, M. tempestiva, M. tenuis, M. texana, M. tischii, 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. 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
Subordinate taxa
M. nelsoniana var. carlottae, M. nelsoniana var. cascadensis, M. nelsoniana var. insularis, M. nelsoniana var. nelsoniana, M. nelsoniana var. porsildiana
Synonyms Saxifraga lyallii, Saxifraga lyallii subsp. hultenii, Saxifraga lyallii var. hultenii Saxifraga tolmiei, Saxifraga tolmiei var. ledifolia Saxifraga nelsoniana, Saxifraga punctata subsp. nelsoniana, Saxifraga punctata var. nelsoniana
Name authority (Engler) Small: in N. L. Britton et al., N. Amer. Fl. 22: 143. 1905 , (Torrey & A. Gray) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1022. 2007 , (D. Don) Small: in N. L. Britton et al., N. Amer. Fl. 22: 147. 1905 ,
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