640804 Dryas incisa Juz.
Distribution
Taimyr - Severnaya Zemlya: Rare
Kharaulakh: Frequent
West Chukotka: Frequent
Wrangel Island: Frequent
South Chukotka: Frequent
East Chukotka: Frequent
Western Alaska: Frequent
Northern Alaska - Yukon: Frequent
Northern arctic Tundra: Rare
Mid Arctic Tundra: Frequent
Southern Arcti Tundra: Frequent
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Frequent
- Juz., Izv. Glavn. Bot. Sada SSSR 28: 315 (1929). Holotype (LE): Siberia: Yakutia, "distr. Kolyma, ad rip. dextr. fl. Kolyma, 110 verst ab Oceano Glaciali", 02. July 1875, leg. Augustinowicz. - Dryas octopetala subsp. incisa (Juz.) Malyschev, Fl. Vost. Sayana: 169 (1965).
- Dryas crenulata sensu A.E. Porsild & Cody (1980) and Cody (1996), non Juz. (1929).
2n=
18 (2x). - Siberia (N, S), Far East (N). - At least three reports.
A report from the Yukon Territory published for D. crenulata (Mulligan and Porsild 1970) may belong here.
Geography: Asian (N/C) - amphi-Beringian: SIB RFE ALA CAN.
Notes: Elven and Murray: Dryas incisa is characterized by crenulate leaves without glands and feathery hairs. Yurtsev proposed it to be a nearly circumpolar species co-occurring with one or more of the species D. octopetala, D. ajanensis, D. punctata, and D. integrifolia in all major areas from Norway throughout Eurasia and North America to eastern Greenland. We rather consider it restricted to Taimyr, northern Yakutia, Chukotka, Alaska, and the Yukon Territory. In these regions it occurs as frequent and forms populations. As seen from Yurtsev's map (1984c), there are only scattered records from Eurasia west of Chukotka. All reports from non-Beringian North America and Greenland are dubious. We suspect that these records are due to technical application of some single characters.
Hultén and Fries (1986) included D. incisa in D. integrifolia when they mapped the latter with an extensive Asian range west to the Lena River area and southern Siberia. We do not follow that view (and obviously Yurtsev did not either).
The molecular data (AFLP: Skrede et al. 2006) throw some doubts on D. incisa as a taxon. The Alaskan and Yukon Territory D. incisa connects to the other North American plants, the Siberian D. incisa to the other Siberian and northeastern European plants. If so, D. incisa may be populations of plants of D. ajanensis, D. octopetala, and perhaps D. punctata (s. str.), without the diagnostic feathery hairs (and glands).
Yurtsev commented on the plant originally described as D. octopetala var. pilosa Bab., raised to species as D. babingtonii A.E. Porsild, Bull. Natl. Mus. Canada 160: 133 (1959): "An alternative point of view should be tested: that the form described by Porsild as D. babingtonii is but a rare phase in populations of D. incisa with reduced branched hairs on leaves: D. octopetala var. pilosa Bab., taking into account that D. octopetala subsp. subincisa itself could originate from an ancient hybridization: D. octopetala subsp. octopetala x D. incisa (Yurtsev 1984c). The tentative range of this taxon i.e., [D. babingtonii]: NOR RUS GRL".
A canescens form of D. incisa is named as var. cana Jurtz., Fl. Arct. URSS 9, 1: 322, 277 (1984), and reported from RFE and ALA.
Higher Taxa
- Dryas [6408,genus]