610211 Betula divaricata Ledeb.
Distribution
Taimyr - Severnaya Zemlya: Present only in the Borderline Arctic
Anabar - Onenyo: Presence uncertain
Kharaulakh: Rare
West Chukotka: Rare
South Chukotka: Presence uncertain
Southern Arcti Tundra: Rare
Shrub Tundra: Scattered
Bordering boreal or alpine areas: Frequent
- Ledeb., Denkschr. Baier. Bot. Ges. 3: 59 (1841). No type cited.
- Betula middendorffii Trautv. & C.A. Mey. in Middend., Reise Sibir. 1, 2, 3: 293 (1856). Holotype (LE)?: Russian Far East: the Okhotsk Sea, "in insula Schantar Magna", 06.-07. July 1844, leg. A. Middendorff.
2n=
(1) 42 (3x). - Siberia (N), Far East (N). - At least three reports.
(2) ca. 48. - Siberia (N). - Zhukova et al. (1973).
(2) 56 (4x). - Far East (N). - At least four reports.
Geography: Asian (NE): SIB RFE.
Notes: Czerepanov (1966) accepted Betula divaricata without special comments, with B. middendorffii as synonym. Yurtsev commented that B. middendorffii is a good species, related to and vicariant for B. glandulosa in northeastern Asia. Hultén (1971a) interpreted B. middendorffii to be a hybrid between B. nana and some tree-forming species. Few or no such tree-forming species are present within the northern parts of its range but Hultén stated that: "The possibility for tree birch pollen to be transported a long way is illustrated by the fact, that hybrids with the tree-birches occur, although very rarely, on East Greenland, where no tree-birches occur." The reported chromosome numbers may indicate a hybrid background of at least parts of the counted material.
Higher Taxa
- Betula [6102,genus]