Iris sibiricaL.

German IrisSiberian iris

WFO wfo-0000783854 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Iris sibirica, photographed by Ксения Волянская
fig. a Ксения Волянская, CC BY 4.0 / 2022-06-12 / obs. 205463992

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.

Native range 27 botanical countries

Regions where Iris sibirica is native: Altay, Kazakhstan, Krasnoyarsk, Mongolia, North Caucasus, Transcaucasus, Türkiye, West Siberia, Austria, Baltic States, Belarus, Bulgaria, Central European Russia, Czechia-Slovakia, East European Russia, France, Germany, Hungary, Italy, North European Russia, Northwest European Russia, NW. Balkan Pen., Poland, Romania, South European Russia, Switzerland, Ukraine AltayKazakhstanKrasnoyarskMongoliaNorth CaucasusTranscaucasusTürkiyeWest SiberiaAustriaBaltic StatesBelarusBulgariaCentral European RussiaCzechia-SlovakiaEast European RussiaFranceGermanyHungaryItalyNorth European RussiaNorthwest European RussiaNW. Balkan Pen.PolandRomaniaSouth European RussiaSwitzerlandUkraine
Native distribution of Iris sibirica, 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.
RegionTDWG codeContinent
Austria AUT EUROPE
Baltic States BLT
Belarus BLR
Bulgaria BUL
Central European Russia RUC
Czechia-Slovakia CZE
East European Russia RUE
France FRA
Germany GER
Hungary HUN
Italy ITA
North European Russia RUN
Northwest European Russia RUW
NW. Balkan Pen. YUG
Poland POL
Romania ROM
South European Russia RUS
Switzerland SWI
Ukraine UKR
Altay ALT ASIA-TEMPERATE
Kazakhstan KAZ
Krasnoyarsk KRA
Mongolia MON
North Caucasus NCS
Transcaucasus TCS
Türkiye TUR
West Siberia WSB

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 418 in flower of 586 examined

Proportion of examined Iris sibirica in flower, by month
Month In flower Examined Share 95% interval
Jan 0 9 0% 0% to 30%
Feb 0 8 0% 0% to 32%
Mar 0 3 too few examined
Apr 2 11 18% 5% to 48%
May 174 187 93% 88% to 96%
Jun 231 249 93% 89% to 95%
Jul 10 43 23% 13% to 38%
Aug 0 20 0% 0% to 16%
Sep 1 28 4% 1% to 18%
Oct 0 6 0% 0% to 39%
Nov 0 11 0% 0% to 26%
Dec 0 11 0% 0% to 26%

Peak flowering in May. Each bar is the share of Iris sibirica 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. 418 of 586 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. 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 2,055 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -19.4 °C -6.2 °C -2.2 °C
Warmest month, mean daily high 20.2 °C 23.2 °C 25.9 °C
Annual rainfall 469 mm 660 mm 1,557 mm
Rainfall in the driest quarter 57 mm 109 mm 280 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 2,055 research-grade observations of Iris sibirica 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 30 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.

  • Biris sibirica (L.) Medik.
  • Iris acuta Willd.
  • Iris angustifolia Gilib.
  • Iris bicolor Mill.
  • Iris erirrhiza Posp.
  • Iris flexuosa Murray
  • Iris mandraliscae Tineo ex Tornab.
  • Iris maritima Mill.
  • Iris pratensis Lam.
  • Iris pseudosibirica Schur
  • Iris sibirica f. albiflora Makino
  • Iris sibirica var. acuta (Willd.) Trevir.
  • Iris sibirica var. albida Regel
  • Iris sibirica var. angustifolia Regel
  • Iris sibirica var. erirrhiza (Posp.) Asch. & Graebn.
  • Iris sibirica var. flexuosa (Murray) Ker Gawl.
  • Iris sibirica var. haematophylla Besser
  • Iris sibirica var. pallida Regel
  • Iris sibirica var. stenopetala Regel
  • Iris sibirica var. typica Maxim.
  • Iris spathulata Cav.
  • Iris stricta Moench
  • Ixia angustifolia Salisb.
  • Limnirion sibiricum (L.) Opiz

and 6 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. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. 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.