Saxifraga hyperborea
Saxifraga cernua
brook saxifrage, pygmy saxifrage, saxifrage hyperboréale
bulblet saxifrage, nodding saxifrage, saxifrage penchée
basal and cauline, (cauline 1–3, dissimilar from basal, reduced);
petiole ± flattened, (2–)5–35 mm;
blade reniform to orbiculate, (2–)3–5(–7)-lobed (lobes rounded), (2–)3–6(–10) mm, thin or slightly fleshy, margins entire, eciliate or sparsely stipitate-glandular, (inconspicuous nonsecreting hydathodes sometimes present), apex acute, surfaces glabrous or sparsely hairy.
basal and cauline, (basal usually ephemeral, gradually dying through growing season, cauline conspicuous, reduced distally);
petiole flattened, (5–)10–60(–90) mm;
blade round to reniform, 3–7(–9)-lobed usually less than halfway to midvein (distal unlobed), (3–)5–18(–20) mm, slightly fleshy, margins entire, eciliate or sometimes sparsely glandular-ciliate, apex rounded, sometimes acute, surfaces glabrous or sparsely stipitate-glandular.
2–5-flowered cymes, sometimes solitary flowers, 1–5 cm, tangled, purple-tipped stipitate-glandular;
bracts petiolate.
2(–5)-flowered paniculate or racemelike thyrses, sometimes solitary flowers, (flowers nodding in bud), some or all flowers but terminal one on each branch often replaced by bulbils, 3–30 cm, stipitate-glandular;
bracts (proximal ephemeral), petiolate or sessile.
(hypanthium U-shaped in longisection, sparsely to densely long stipitate-glandular);
sepals erect, (sometimes purple), ovate to lance-oblong, (1.5–2.1 mm wide), margins eciliate, surfaces ± stipitate-glandular;
petals purple or white, often midvein ± purplish, faded when dried, not spotted, oblong, (1.5–)2–3.4(–5) mm, equaling or to 1.5 times sepals;
ovary 1/2 inferior.
sepals erect, (sometimes reddish), oblong, margins glandular-ciliate, surfaces short-stipitate-glandular;
petals white, not spotted, obovate to spatulate, 5–12 mm, longer than sepals;
ovary superior.
= 26.
= 24, 36, 48, 52, 56, 60, 70, 72.
Saxifraga hyperborea
Saxifraga cernua
Reports of Saxifraga hyperborea from Mount Washington, New Hampshire (e.g., Á. Löve and D. Löve 1964) require confirmation; all specimens examined from this location appear to be S. rivularis. C. L. Hitchcock (1961) treated all western material as S. debilis, including that of the Pacific Northwest that is included here. For Colorado, W. A. Weber (1990) appears to have applied the name S. rivularis to what we call S. hyperborea, and S. hyperborea subsp. debilis to what we call S. debilis. P. K. Holmgren and N. H. Holmgren (1997) included under their broad concept of S. rivularis both S. hyperborea and S. debilis, noting that the plants had gone usually under the latter name. Both species are present in the Rockies and the Intermountain Region.
In northeastern North America, Saxifraga hyperborea and S. rivularis are often sympatric, although the latter is absent from the extreme north. The major distinguishing feature between diploid S. hyperborea and tetraploid S. rivularis is the presence of rhizomes in the former and their absence in the latter (see key), a character that is sometimes difficult to interpret on herbarium sheets. Plants of S. hyperborea are usually smaller (2–5 cm) and reddish (sometimes green), with usually three- to five-lobed leaves and petals about one and one-half times longer than sepals, while plants of S. rivularis are taller (5–10 cm) and usually green (although sometimes reddish, particularly in the western var. arctolitoralis), with usually five-lobed leaves and petals two to three times longer than sepals.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Saxifraga cernua plants rarely set seed; they bear bulbils among the basal leaves. Some reports of S. sibirica Linnaeus from Canada are misidentifications of this species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria, 
SW CO Wildflowers 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
Go Botany
MN Wildflowers
