Taxonomic Status of Three Caucasian Snowdrops: Galanthus alpinus Sosn., G. bortkewitschianus Koss and G. caucasicus (Baker) Grossh.

Abstract

Galanthus alpinus, G. caucasicus and G. bortkewitschianus occur in the Caucusus (within the limits of Russia, Georgia and Armenia), and in the neighbouring area of Lazistan (in NE Turkey). At the present time, these taxa are considered to represent three closely related but distinct species, which are recognised in the most recent monograph of Galanthus (Artjushenko 1970), and in modern regional Floras of the Caucasus. The aim of this paper, however, is to demonstrate that they are conspecific. According to Artjushenko (1970) G. caucasicus, G. alpinus and G. bortkewitschianus form a taxonomic group, defined by the unique combination of supervolute leaf vernation, glaucous leaves and a single green mark on each of the inner perianth segments. Two anatomical characters were also used to group these species: (1) 'leaves with hollows' (mesophyll cavities, as seen in transverse section) and (2) rightangled [oblong] epidermal cells (Artjushenko 1966, 1967). Artjushenko separated these species mainly on the basis of morphometric characters: for example, in her key (see Artjushenko 1969) Galanthus caucasicus and G. alpinus were separated by leaf width (1 1.6 cm and 2 2.5 cm, respectively), and G. alpinus and G. bortkewitschianus were separated by flower size (1.5 cm and 1.5 2 cm long, respectively) and by the fact that mature fruits are not known to develop in the latter species.