Micranthes pensylvanica(L.) Haw.

Carolina saxifrage

WFO wfo-0001220656 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Micranthes pensylvanica, photographed by Ryan Sorrells
fig. a Ryan Sorrells, CC BY 4.0 / 2022-06-11 / obs. 205635854
Micranthes pensylvanica, photographed by Paul Roots
fig. b Paul Roots, CC BY 4.0 / obs. 202781120
Micranthes pensylvanica, photographed by Erin Snyder
fig. c Erin Snyder, CC BY 4.0 / obs. 200427032
Micranthes pensylvanica, photographed by Steven Lamonde
fig. d Steven Lamonde, CC BY 4.0 / obs. 199201557
Micranthes pensylvanica, photographed by Steven Lamonde
fig. e Steven Lamonde, CC BY 4.0 / obs. 199201575
Micranthes pensylvanica, photographed by Steven Lamonde
fig. f Steven Lamonde, CC BY 4.0 / obs. 199201603
Micranthes pensylvanica, photographed by Steven Lamonde
fig. g Steven Lamonde, CC BY 4.0 / obs. 199193978
Micranthes pensylvanica, photographed by Steven Lamonde
fig. h Steven Lamonde, CC BY 4.0 / obs. 199194080

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
05150965
Filed as
Micranthes pensylvanica (L.) Haw.
Det. by
D. Cummings 2023-01-01
Collected
P. Butter 2023-05-27
Origin
US
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 26 botanical countries

Regions where Micranthes pensylvanica is native: Connecticut, Delaware, Illinois, Indiana, Iowa, Maine, Manitoba, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Ontario, Pennsylvania, Rhode I., Saskatchewan, Tennessee, Vermont, Virginia, West Virginia, Wisconsin ConnecticutIllinoisIndianaIowaMaineManitobaMarylandMassachusettsMichiganMinnesotaMissouriNew HampshireNew JerseyNew YorkNorth CarolinaOhioOntarioPennsylvaniaSaskatchewanTennesseeVermontVirginiaWest VirginiaWisconsin DelawareRhode I.
Native distribution of Micranthes pensylvanica, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Connecticut CNT NORTHERN AMERICA
Delaware DEL
Illinois ILL
Indiana INI
Iowa IOW
Maine MAI
Manitoba MAN
Maryland MRY
Massachusetts MAS
Michigan MIC
Minnesota MIN
Missouri MSO
New Hampshire NWH
New Jersey NWJ
New York NWY
North Carolina NCA
Ohio OHI
Ontario ONT
Pennsylvania PEN
Rhode I. RHO
Saskatchewan SAS
Tennessee TEN
Vermont VER
Virginia VRG
West Virginia WVA
Wisconsin WIS

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 240 in flower of 489 examined

Peak flowering in Jun. Each bar is the share of Micranthes pensylvanica observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 240 of 489 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 6 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 1,975 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -14.9 °C -9.7 °C -4.6 °C
Warmest month, mean daily high 23.6 °C 26.6 °C 28.9 °C
Annual rainfall 807 mm 1,108 mm 1,469 mm
Rainfall in the driest quarter 76 mm 210 mm 314 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,975 research-grade observations of Micranthes pensylvanica that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 42 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Evaiezoa pensylvanica Raf.
  • Micranthes forbesii (Vasey) Bush
  • Micranthes hirta Haw.
  • Micranthes pensylvanica f. fultior (Fernald) Bush
  • Micranthes pensylvanica var. crassicarpa (A.M.Johnson) Bush
  • Micranthes pensylvanica var. dichotoma Bush
  • Micranthes pensylvanica var. forbesii (Vasey) Bush
  • Micranthes pensylvanica var. hirsuta Bush
  • Micranthes pensylvanica var. purpuripetala (A.M.Johnson) Bush
  • Micranthes pensylvanica var. tomentosa Bush
  • Micranthes pensylvanica var. winnebagoensis (A.M.Johnson) Bush
  • Micranthes semipubescens Haw.
  • Robertsonia pensylvanica Link
  • Robertsonia semipubescens (Sweet) Link
  • Saxifraga caroliniana Sternb. ex Ser.
  • Saxifraga crassicarpa A.M.Johnson
  • Saxifraga forbesii Vasey
  • Saxifraga forbesii f. bracteosa G.W.Burns
  • Saxifraga marylandica hort. ex Sternb.
  • Saxifraga palustris Link
  • Saxifraga pensylvanica L.
  • Saxifraga pensylvanica f. bractealis G.W.Burns
  • Saxifraga pensylvanica f. bracteata G.W.Burns
  • Saxifraga pensylvanica f. congesta G.W.Burns

and 18 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. USDA PLANTS Database. common name, checklist symbol SACA20. public domain. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.