Saghatelyan, Anna .
Floristic analysis: a comparison of the flora Armenia and Texas.
ARMENIA is a mountainous Ciscaucasian country with some 3,342 sp. of vascular plants. Almost half of the species are of Tethyan origin. The majority of them are xerophytic cenozoic derivatives of the more ancient Laurasian historic element. Less abundant are derivatives of the Gondwanan element. A few relictual euxinian and hyrcanian species here reveal fading off connections of the flora with the refuges of the two mesophyllous Tertiary forest floras: the northern (warm) temperate branch of the Laurasian flora (Euxine) and its southern branch (Hyrcania). The latter represents Tethyan notophyllous mountainous forest flora. The Sino-Himalayan Subregion was a major source of that subtropical flora.
A comparison of the spectra of families in the floras Armenia and Texas will be presented. Texas has some 5,389 species and represents a contact territory of the Boreal and Madrean Subkingdoms and at similar latitude. Numerous subtropical sclerophyllous species in Texas are its major peculiarity. Armenia has only a few evergreen species and immediate connections to the Paleotropical flora. The largest families of the both floras are Asteraceae, Fabaceae, Poaceae.
Euphorbiaceae, Malvaceae, Solanaceae, Onagraceae are on much higher positions in flora Texas, due to migration from South America since Pliocene, while Brassicaceae, Rosaceae, Caryophyllaceae, Boraginaceae s.str., Lamiaceae, and Apiaceae are much more diversified in Armenia, with the predominance of the xeric and/or mountainous species of recent origin in Neogene. This is congruent with the high diversity of these groups in Eastern Asia or in the whole Tethyan subkingdom. More specialized families Boraginaceae, Scrophulariaceae, Lamiaceae, and especially Asteraceae, have generic composition essentially different in the two floras, while in Rosaceae of the both floras many genera are the same. This may point to earlier North Laurasian routs of dispersal via NALB or BLB and probability of the origin from common tropical ancestors for many rosaceous lineages.
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1 - McMurry University, Biology, McM Station Box 368, Abilene, Texas, 79697, USA
Presentation Type: Oral Paper:Papers for Topics
Location: 134/Performing Arts Center
Date: Wednesday, August 2nd, 2006
Time: 9:15 AM