Systematik und Chorologie der Gattung Odontites Ludwig s.l. (Scrophulariaceae)

Abstract

Summary The classification of the hemiparasitic genus Odontites L udwig s.l. ( Scrophulariaceae-Rhinanthoideae , tribe-sub tribe Rhinantheae Euphrasiinae ) was studied by means of phenetic-numerical investigations, including PCA, on the basis of 32 characters and 83 character-states. The genus in its traditionally wide sense had to be split into five genera, three of them being monotypic: Odontites L udwig (25 species and 15 subspecies), Macrosyringion R othm . (2), Odontitella R othm . (1), Bornmuellerantha R othm . (1) and Bartsiella B olliger (1). Odontites in its restricted sense represents most probably a natural (monophyletic) group, being characterised by its unique pollen morphology consisting of an irregular microreticulate exine-sculptering, thinned mesocolpi and subtriangular ambo In most other characters the genus is manifold and therefore impossible to distinguish by any singular conspicuous character. Odontites is a genus of west-mediterranean origin, 18 of its 25 species are stenochoric endemics of the macaronesian-mediterranean region, all being restricted to small areas on isles or moutain massifs. Only three species are relatively widespread, their areas extending over more than one floristic region: O. viscosus (northeastwards to the Valais), O.luteus (sub mediterranean - centraleuropenean - pontic) and especially the mainly temperate - eurasiatic variable group of the Red Bartsia O. vernus , which is the only representative of the genus to overstep the Ural chain. Concerning phylogeny, Odontites emerged from taxa closely related to the huge genera Bartsia and Euphrasia, both having developed in other regions of the world than Odontites . In contrast to these almost worldwide distributed genera, the geographically much more restricted genus Odontites lacks long-lived perennial species, consisting mostly of summerannuals. With the taxonomic revision presented here the number of genera of the tribe Rhinantheae amounts to 29; of these, 18 occur in Europe and the mediterranean region, but only 7 genera are endemic to this area, which represents a secondary development center of the tribe whose roots have to be searched for in east Asia, the centre of origin of important genera like Pedicularis and probably cradle of the family Scrophulariaceae as a whole.