Mediterran‐mitteleuropäische Florenbeziehungen im Lichte cytotaxonomischer Befunde

Abstract

1) A survey of cytological, genetical, and other evidence for phylogenetic differentiation of higher plant groups in Mediterranean and Central European areas is presented.2) Methods and possible results are demonstrated, using as an example the closely related Rubiaceous genera Cruciata and Valantia, where polyploidy, descending dysploidy, increase of heterochromatin, change from allogamy to autogamy, and from perennials to annuals suggest salient features of geographical and ecological differentiation.3) The phylogeny of more than 70 other Europe groups of Ferns and Angiosperms from the Mediterranean and Central is briefly discussed in chapters on woody plants, perennials of forest, alpine, and other open habitats, and annuals.4) The sequence from woody plants to annuals is on the average paralleled by increasing intensity of cytogenetical differentiation (polyploidy, dysploidy, etc.) and evolutionary versatility (instead of evolutionary conservatism), and by decreasing age of groups. Furtheron, there are more Holarctic and Eurasian elements in the former, but more European, Mediterranean and Oriental elements in the later groups.5) In woody groups our examples suggest ancient affinities between relic Macaronesian resp. Colchic laurel forest elements and even more primitive Southeast‐Asian relatives (Prunus subg. Laurocerasus), origin of Mediterranean sclerophylls form laurel forest progenitors related to species in Macaronesia and East Asia (Viburnum sect. Tinus), and close affinities between Mediterranean evergreens and European summergreens (Rubus sect. Moriferi); these phenomena probably date back from the early to the later Tertiary.6) Examples from perennial groups stress the importance of Macaronesian, Mediterranean, and Oriental areas as centers for old and primary geographical differentiation (West/East etc.) as well as for ecological radiation from laurel, sclerophyll and temperate forest elements to those of open, warm and/or cold (alpine‐arctic) habitats, probably from Mid‐Tertiary onward (Polystichum setiferum‐P. lonchitis. Lotus corniculatus agg., Cyclamen purpurascens, Cruciata‐Valantia, Galium mollugo agg., Campanula subsect. Heterophylla, Brachypodium, Dactylis glomerata agg., etc.).7) The repeated origin of annual from perennial groups (Anagallis subg. Anagallis. Cruciata‐Valantia, Carthamus, Calendula, Crepis, Brachypodium, etc.) and their further differentiation was centered in Oriental, southeastern and southwestern Mediterranean areas, and seems to have been furthered by succsssive xerothermic periods since the later Tertiary.8) During the Pleistocene and its extreme climatic changes European floras became depauperate : Mediterranean areas then served as most important centers of conservation for many primitive progenitors of younger Central European elements. This has been demonstrated for numerous groups from forest (e. g. Polypodium vulgare agg., Paeonia, Rubus sect. Morveri. Lamiastrum, etc.), open (Pulsatilla vulgaris agg., Pinguicula sect. Pinguicula, Veronica hederifolia agg., Galium aparine agg., Anthoxanthum odoraturn agg., Dactylis glomerata agg., etc.), and even alpine habitats (Erysimum sylvestre agg., Poa badensis agg., etc.).9) During and after the glaciations of the Pleistocene and during the Holocene intensive secondary phylogenetic differentiation and speciation took place: In the Central Europeanvegetation and flora many of the depleted niches and lateron those newly created by man were filled predominantly from the South. Proof for this comes from dysploid series leading from Mediterranean to Central European representatives (Myosotis sylwatica, Leucojum, Carex sempervirens group, Crepis sect. Phytodesia, etc.), but more typically from numerous polyploid (end partly apomictic) complexes. Many of these polyploid Central European groups and species have originated through hybrid combinations from geographically and/or ecologically diverse diploids : from various (sub)mediterranean( ‐montane) progenitors (Rubus sect. Morgeri, Aphanes, Sorbus sect. Aria and sect. Torminaria, Paeonia, Dentaria, Galium pusillum agg., Cr uciata glabra, Knautia drymeia agg. and K. arvensis agg., Carthamus, Poaceae‐Honermeae, etc.), from further addition of genomes from eastern‐continental (Pulsatilla halleri agg., Lamiastrum, Veronica ser. Austriacae and V. hederifolia agg., etc.), boreal (Polypodium vulgare agg., Polystichum aculeatum agg., etc.), or montanealpine elements (Cerastium arvense, Arenaria serpyllifolia agg., Ceum subg. Geum, Lotus corniculatus agg., Tanacetum alpinum agg., Anthoxanthum odoratum agg., Poa annua agg., etc.), or even from several of such types (Potentilla werna agg., Thlaspi, Campanula sect. Heterophylla, Galium mollugo agg., Iris pumila, ete.).