6417 Sorbus L.
- L., Sp. Pl.: 477 (1753).
- Excluded: Sorbus aucuparia subsp. praemorsa.
Notes: Sorbus is a complicated genus, especially in Europe where a few sexual diploids (2n = 34, or secondary diploids, as x = 17 is a quite high base number) are accompanied by several large, regional complexes of hybridogeneous and agamic triploids (2n = 51) and tetraploids (2n = 68) usually treated as species (agamospecies). For an early study of the complexities, see Liljefors (1953). The majority of the taxa that reach the Arctic, and for which chromosome counts are reported, are diploids and probably sexuals, the exception being the tetraploid S. groenlandica. They all belong to a widely defined S. aucuparia group. An old but thorough treatment of the North American variation is Jones (1939).
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Source: Isfisk at Wikispecies
