Panarctic Flora

4202 Cerastium L.

• L., Sp. Pl.: 437 (1753).
• Dichodon Bartl. in Rchb., Nomencl.: 205 (1841).
• Casual: Cerastium glomeratum.
• Excluded: Cerastium arcticum var. sordidum (see C. beeringianum).

Notes: There is molecular support for recognition of subg. Dichodon (with Cerastium cerastoides as the arctic representative) apart from subg. Cerastium. Dichodon is the sister of the other Cerastiums in the phylogeny of Scheen et al. (2003). There is no support for the proposal of Löve and Löve (1975a, 1976a) to include in Dichodon also the "Strephodon" group with C. davuricum and C. maximum. The Löves based their conclusion on a difference in chromosome number (x = 19 vs. 18). The species of "Strephodon" appear here and there in the mentioned phylogeny, not as a monophyletic group.

Brysting and Elven: Most authors consider x = 18 to be the base chromosome number of Cerastium and the few counts of 2n = 54 (then triploids) to represent hybrids. The predominant number 2n = 38, found in Dichodon and in C. davuricum and C. maximum, may then be based on an aneuploid base number of x = 19. See Brett (1950, 1952, 1955).

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  Source: Slaunger at Wikispecies