Arctopoa eminens(J.Presl) Prob.

largeflower speargrass

WFO wfo-0000848444 Accepted WFO 2026-06 8 photographs CC BY / CC BY-SA

Plate 1 figs. a–h · 4 observations

This species has been photographed under an open licence only 4 times, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.

Arctopoa eminens, photographed by Eric Knight
fig. a Eric Knight, CC BY 4.0 / 2018-07-25 / obs. 22576399

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
Smithsonian, US National Herbarium
Accession
US 376539
Filed as
Arctopoa eminens (J.Presl) Prob.
Det. by
Poaceae Reorganization Project
Collected
W. Trelease 1899-07-26
Origin
US
The sheet
View the digitised specimen (CC0 1.0)

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 14 botanical countries

Regions where Arctopoa eminens is native: Japan, Kamchatka, Khabarovsk, Kuril Is., Magadan, Primorye, Sakhalin, Alaska, Aleutian Is., British Columbia, Labrador, Newfoundland, Ontario, Québec JapanKamchatkaKhabarovskMagadanPrimoryeSakhalinAlaskaBritish ColumbiaLabradorNewfoundlandOntarioQuébec
Native distribution of Arctopoa eminens, 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
Japan JAP ASIA-TEMPERATE
Kamchatka KAM
Khabarovsk KHA
Kuril Is. KUR
Magadan MAG
Primorye PRM
Sakhalin SAK
Alaska ASK NORTHERN AMERICA
Aleutian Is. ALU
British Columbia BRC
Labrador LAB
Newfoundland NFL
Ontario ONT
Québec QUE

Not drawn on the map: Kuril Is., Aleutian Is.. We hold no public-domain boundary for these regions, so they are listed rather than guessed at.

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.

Where it actually grows measured, from 52 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -19.9 °C -12.8 °C -3.2 °C
Warmest month, mean daily high 11.4 °C 15.7 °C 21.4 °C
Annual rainfall 669 mm 1,053 mm 1,392 mm
Rainfall in the driest quarter 50 mm 188 mm 250 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 52 research-grade observations of Arctopoa eminens 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.

Also published as 13 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.

  • Arctopoa alexeji (Sofiekova & Vorosch.) Prob.
  • Arctopoa alexejii (Sofiekova & Vorosch.) Prob.
  • Arctopoa reverta Prob.
  • Dupontopoa dezhnevii Prob.
  • Festuca neogaea Steud.
  • Poa alexeji T.M.Sofiekova & Vorosch.
  • Poa alexejii Sofiekova & Vorosch.
  • Poa eminens J.Presl
  • Poa eminens var. alexeji (Sofiekova & Vorosch.) Vorosch.
  • Poa glumaris Trin.
  • Poa glumaris var. kurilensis (Hack.) Kudô
  • Poa kurilensis Hack.
  • Poa trinii Scribn. & Merr.

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 POEM. 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.