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Howell's saxifrage

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

Habit Plants solitary or in groups, with bulbils on caudices. Plants mat-forming, (stems trailing, thin, basally slightly woody), with slender, woody caudices.
Leaves

basal;

petiole flattened, 1–4 cm;

blade oblong to narrowly ovate, 1–2(–3) cm, ± fleshy, base attenuate, margins sharply serrate, eciliate, surfaces sparsely tangled, reddish brown-hairy abaxially, glabrous adaxially.

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.

Inflorescences

5–10(–20)-flowered, very open, lax, ± flat-topped cymes or thyrses, 5–10(–20) cm, glabrate to sparsely purple-tipped stipitate-glandular; (bracts glabrous).

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

Flowers

sepals strongly reflexed, elliptic, (surfaces glabrous);

petals white, not spotted, obovate to elliptic, clawed, 2.5–4.5 mm, longer than sepals;

filaments linear, flattened;

pistils distinct almost to base;

ovary ± superior.

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).

Capsules

purple, valvate.

green, purple mottled, valvate.

2n

= 30.

Micranthes howellii

Micranthes tolmiei

Phenology Flowering early spring–early summer. Flowering summer.
Habitat Wet, rocky ledges and crevices Arctic and alpine tundra, fell-fields
Elevation 0-900 m (0-3000 ft) 500-4000 m (1600-13100 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CA; ID; MT; NV; OR; UT; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Source FNA vol. 8, p. 63. 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. 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
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
Synonyms Saxifraga howellii Saxifraga tolmiei, Saxifraga tolmiei var. ledifolia
Name authority (Greene) Small: in N. L. Britton et al., N. Amer. Fl. 22: 140. (1905) (Torrey & A. Gray) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1022. 2007 ,
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