Panarctic Flora


361220 Ranunculus arcticus Richardson


Svalbard - Franz Joseph Land: Scattered
Polar Ural - Novaya Zemlya: Scattered
Yamal - Gydan: Rare
Taimyr - Severnaya Zemlya: Frequent
Anabar - Onenyo: Scattered
Kharaulakh: Frequent
Yana - Kolyma: Scattered
West Chukotka: Scattered
Wrangel Island: Frequent
South Chukotka: Rare
East Chukotka: Frequent
Western Alaska: Scattered
Northern Alaska - Yukon: Frequent
Central Canada: Frequent
Hudson Bay - Labrador: Frequent
Ellesmere Island: Scattered
Western Greenland: Scattered
Eastern Greenland: Scattered
Northern arctic Tundra: Rare
Mid Arctic Tundra: Frequent
Southern Arcti Tundra: Frequent
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Scattered

2n= (1) 28 32 (4x). - Europe (N), Siberia, Far East (N), Alaska, Canada, Greenland. - Numerous reports.
(2) 48 (6x). - Canada, Greenland. - At least five reports.
Not included: Reports of 2n = 14, 16, and 30 under the name R. affinis from southern Siberia and India. These mainly more low-ploid numbers may belong to R. pedatifidus (see below) or relatives and are an additional reason for keeping R. arcticus and R. pedatifidus apart.

Geography: Circumpolar-alpine: NOR RUS SIB RFE ALA CAN GRL.

Notes: Rebristaya and Elven: Richardson's name Ranunculus arcticus from March 1823 predates Robert Brown's R. affinis from late 1823. We assume that the names refer to the same species. The name R. pedatifidus Sm. (see Excluded taxa) has often been applied for arctic plants but in our opinion misapplied. The arctic and northern plants are related to but not the same as the central Asian R. pedatifidus. Ranunculus arcticus differs from R. pedatifidus in carpels glabrous or short-pubescent, cauline leaves with entire segments, bases of stems lacking scales, and probably in ploidy level.

Löve and Löve (1975a) reported five hexaploid counts under the name R. affinis, mostly from the Arctic. They reported numerous tetraploid counts under the name R. wilanderi, all from areas far outside the range of this local Svalbard agamospecies of the R. auricomus group (Ericsson 2001). They applied names and sorted counts fully disregarding morphology, taxonomy, and original publications. Ranunculus arcticus occurs with at least two ploidy levels: tetraploid and hexaploid. Tetraploid plants are known throughout, whereas hexaploid plants are known from Canada and Greenland.

In the assumedly diploid R. pedatifidus, Rozanova (1932) found the pollen to be good and found no fruit-set after emasculation and pollination with pollen from R. auricomus. The reproductive system of the polyploid R. arcticus is not known but agamospermy - as in the R. auricomus group - cannot be excluded (see Böcher and Larsen 1950 and Jørgensen et al. 1958 for cytological indications). Seed-set in R. arcticus is mostly abundant, often an indication of agamospermy (or very efficient self-fertilization) in Ranunculus.

Higher Taxa