The seeds of Gentiana show high diversity in size, shape and surface pattern. Until now, seeds of only a limited number of taxa have been studied in detail and their utility in the subgeneric classification of Gentiana has not been evaluated. In this study we investigated seed micromorphology of the poorly known sections Pneumonanthe, Frigidae and Isomeria. In order to evaluate the relevance of seed sculpturing for taxonomy, we selected qualitative characters of seed shape and testa ornamentation of all documented sections and performed cluster analyses based on presence and absence of coded characters. Several new scanning electron microscopy pictures of seeds provided a number of valuable characters for the subgeneric differentiation of Gentiana. The results of the cluster analyses of seed characters generally support the sectional classification given by former authors. However, the European Gentiana asclepiadea does not group together with other taxa of section Pneumonanthe, but clusters near to the strictly European section Gentiana. Gentiana froelichii, endemic to the south-east Alps and treated traditionally within section Frigidae, clusters together with taxa of the European section Ciminalis. Our results reveal that seed micromorphology supports the reassignment of some taxa incertae sedis within Gentiana.

Small-scale vegetational patterns of Georgian lowland and montane forests and wetlands are documented by species per vegetation unit, function of species in particular vegetation units and vegetational sketches. The humid warmtemperate climate of western Georgia contributes to a different spatial pattern than known for most of Europe. One characteristic feature of western Georgian relict vegetation is the co-occurrence of 'Mediterranean', 'Submediterranean', temperate, and Tertiary relict species, as well as of species normally confined t o either zonal or azonal vegetation, in the same or closely related vegetation units. The extant distribution of Tertiary relict taxa strongly depends on how they are niching into changing environments. Niching strategies are assumed crucial for extinction or survival in times of rapid climatic/environmental changes. For Tertiary relict plant taxa in western Georgia we found four different niching strategies which also hold true of other northern hemispheric Tertiary relict plant taxa. Some amphibians and reptiles display similar distribution patterns and niching strategies as do relict plant taxa. A number of relict taxa in the warm humid regions of western Georgia occupy niches in swamp forests which might represent 'primeval' environments of species which are at present also elements of meso-Mediterranean vegetation and of thermophilous forest edges and hedges in Central Europe. 0 2001 The Linnean Society of London ADDITIONAL KEYWORDS: Macaronesian-Mediterranean floral region -Colchisecological adaptationzonality herpetofauna.

Pterocarya fraxinifolia (Lam.) Spach., a relict tree species of the Juglandaceae family, is native to the Great Caucasus, Anatolia, and to the Hyrcanian forests of the southern Azerbaijan and Northern Iran. In this study, the phylogenetic relationship of the species, sampled in selected Iranian populations, and the global biogeography of the genus Pterocarya were addressed. Leaves were collected from 8 to 10 trees from three geographically isolated habitats. The samples were analyzed with nuclear (internal transcribed spacer [ITS] regions) and chloroplast (trnH-psbA) DNA markers. The obtained results were compared and analyzed with the data registered in NCBI GenBank. It is reported that the ITS regions varied from 644 to 652 for Pterocarya genus, but we did not observe polymorphisms for Iranian Pterocarya. The phylogenetic tree divided the Pterocarya genus in three clades: clade 1 grouping exclusively the samples P. fraxinifolia, clearly separated from the East Asiatic taxa; clade 2 that includes the species P. hupehensis and P. macroptera; clade 3 clustering P. stenoptera and P. tonkinensis. Although the Iranian Pterocarya samples and P. fraxinifolia from the Caucasus were in the same clade, they presented two different secondary structures. The Iranian populations showed the maximum genetic distance with P. stenoptera and P. tonkinensis. Our analysis demonstrates that the traditional division of all the six species sampled throughout their distribution area as well as the phylogeny of the genus Pterocarya needs to be reviewed.

The taxonomic position of western Asian members of Gentiana sect. Pneumonanthe has long been a matter of conflict. In this paper, the six western Asian species currently recognized as belonging to sect. Pneumonanthe (G. boissieri, G. calycina, G. freyniana, G. gelida, G. paradoxa, and G. septemfida) are compared and their relationships established using a morphological phylogenetic analysis. Seed testa and flower and leaf morphological characters were studied and 11 characters were selected for a cladistic analysis. Euro‐Siberian and Far Eastern taxa of sect. Pneumonanthe (G. pneumonanthe and G. scabra) were used as outgroups. Our results suggest the presence of two morphologically distinct clades within the western Asian gentians: a Septemfida and a Gelida clade. G. calycina and G. freyniana show close affinities to G. boissieri and G. gelida, and are distinct from G. septemfida s.l. Biogeographical aspects of the two groups are discussed. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 152, 197–208.

Gentiana cachemirica is a rare plant from northern Pakistan and northwestern India. The sectional position of this species has been a matter of considerable debate. Various authors have placed Gentiana cachemirica in one of three different sections -Gentiana sect. Isomeria, Gentiana sect. Kudoa or Gentiana sect. Pneumonanthe. The present paper assesses the taxonomic affinities of this species using a detailed study of its morphology accompanied by morphological phylogenetic and cluster analyses. Characters of the seed testa, corolla morphology and growth architecture were studied for selected species from the above-mentioned sections and closely related Gentiana sect. Cruciata. Representatives of Gentiana sect. Ciminalis were used as outgroups. Our results suggest that G. cachemirica belongs to Gentiana sect. Pneumonanthe and that its affinities are closer to the Western Asiatic group of this section.