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bog saxifrage, Oregon or bogsaxifrage, Oregon saxifrage

dotted saxifrage, heartleaf saxifrage, Nelson's saxifrage, saxifrage

Habit Plants solitary or in clusters, with caudex or thick, fleshy rhizomes. Plants solitary or tufted, with bulbils on branched caudices, rhizomatous.
Leaves

basal;

petiole indistinct, flattened, 3–10 cm;

blade linear to oblanceolate, 6–25 cm, fleshy, base cuneate, margins serrulate to denticulate, ciliate, surfaces glabrous or sparsely hairy.

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

(30–)50+-flowered, open to ± crowded, conic to cylindric thyrses, 25–125 cm, hairy proximally, yellow- to pink-tipped stipitate-glandular distally.

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, ovate to triangular;

petals white, not spotted, broadly elliptic to obovate and 2 times as long as sepals, sometimes oblanceolate and equaling or shorter than sepals, clawed, 2–5 mm;

filaments linear, flattened;

pistils connate to 1/2 their lengths;

ovary 1/2+ inferior, often appearing superior in fruit.

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 reddish purple, folliclelike.

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

2n

= 38, 76.

Micranthes oregana

Micranthes nelsoniana

Phenology Flowering early spring–summer.
Habitat Bogs, marshes
Elevation 100-2500 m (300-8200 ft)
Distribution
from FNA
CA; CO; ID; MT; NV; OR; WA; AB
[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

In both habitat and morphology, Micranthes oregana is similar to M. pensylvanica. A thorough investigation of the two species, especially the populations in Colorado that are disjunct from those in Montana, is needed to clarify relationships. The name Saxifraga integrifolia was misapplied to M. oregana by early California authors.

(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.
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.
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.
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.
var. insularis
4. Leaf blades thin, not fleshy; pistils connate to 3/4 their lengths; nw Canada, Alaska.
var. porsildiana
Source FNA vol. 8, p. 67. FNA vol. 8, p. 54.
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. idahoensis, M. integrifolia, M. lyallii, M. marshallii, M. micranthidifolia, M. nelsoniana, M. nidifica, M. nivalis, M. nudicaulis, M. occidentalis, M. odontoloma, 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. 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 oregana, Saxifraga montanensis, Saxifraga oregana var. montanensis Saxifraga nelsoniana, Saxifraga punctata subsp. nelsoniana, Saxifraga punctata var. nelsoniana
Name authority (Howell) Small: in N. L. Britton et al., N. Amer. Fl. 22: 138. 1905 , (D. Don) Small: in N. L. Britton et al., N. Amer. Fl. 22: 147. 1905 ,
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