420211c Cerastium regelii taxon jenisejense (Hultén)
Distribution
Northern Fennoscandia: Rare
Kanin - Pechora: Frequent
Polar Ural - Novaya Zemlya: Frequent
Yamal - Gydan: Frequent
Taimyr - Severnaya Zemlya: Frequent
Anabar - Onenyo: Scattered
Kharaulakh: Frequent
Yana - Kolyma: Rare
West Chukotka: Scattered
East Chukotka: Rare
Mid Arctic Tundra: Scattered
Southern Arcti Tundra: Frequent
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Frequent
- Cerastium jenisejense Hultén, Svensk Bot. Tidskr. 50: 473 (1956). Holotype (S G-7175!): Siberia: Jenisei, "Nikandrovskij ostrov 7020' n.lat.", 20. Aug. 1876, leg. H.W. Arnell.
Geography: European (NE) - Asian (N/C): RUS SIB RFE?
Notes: Some of the previous comments concerning taxon jenisejense during the PAF work are included below.
Elven and Petrovsky: We consider as taxon jenisejense Asian plants that differ from Cerastium beeringianum in trailing growth and in semi-hemisphaerical calyx with short and sometimes subobtuse sepals, and from C. regelii (subsp. regelii and subsp. caespitosum) in profuse hairs on all vegetative parts and a densely matted growth. The calyx and sepals are in common with American C. regelii but the plant differs in the pubescence (in many populations, and retrorse hairs on the lower internodes like in C. beeringianum) and in the matted growth.
Heide et al. (1990) cultivated high-arctic C. regelii subsp. caespitosum and low-arctic taxon jenisejense under uniform conditions and found the differences (flowering vs. bulbil production, growth form and branching, pubescence) to be phenotypic responses to day length. We have seen the same reaction when cultivating C. regelii subsp. caespitosum in greenhouse, except for the pubescence. This densely pulvinate and glabrous plant becomes a profusely branched mat of very long, straggling shoots in the greenhouse but still glabrous. We are not convinced that the results of Heide et al. (1990) can be generalized to cover the variation under natural conditions. Taxon jenisejense occurs as a boreal to southern arctic plant in northern Siberia and perhaps Chukotka, together with C. beeringianum but not with C. regelii subsp. caespitosum. We have observed no transition between taxon jenisejense and C. regelii subsp. regelii or C. regelii subsp. caespitosum, neither in the field nor in the herbarium material, but rather co-occurrence in a few sites. However, the study of Heide et al. (1990) supports the data on very late flowering in subsp. caespitosum at the highest latitudes, i.e., as governed by day length.
Higher Taxa
- Cerastium regelii [420211,species]