Karyomorphology of Davidia involucrata and Camptotheca acuminata, with special reference to their systematic positions

Davidia involucrata Baill. and Camptotheca acuminata Decne were investigated and compared karyomorphologically. Their idiogrammatic formulae are, respectively, 2n = 42 = 20m (2SAT) + 16sm + 4st + 2t and 2n = 42 = 22m (2SAT) + 14sm + 4st + 2t. The plants are very similar: both belong to the 213 asymmetry karyotype (the karyotypes are reported here for the first time) and in both the prophase chromosomes are of the interstitial type. Davidia is believed to be closely related to Camptotheca. We do not consider it appropriate to remove Davidia from Camptotheca into a different family or subfamily. The cytological data support Davidia and Camptotheca forming a subfamily (Davidioideae) of the broadly circumscribed Cornaceae. (C) 2004 The Linnean Society of London.