Eastern Asia as a Living Museum for Archaic Angiosperms and Other Seed Plants

Abstract

Asia, even excluding Malaysia, has the richest family and subfamily flora of angiosperms in the world, 478 of 755 total families and additional subfamilies recognized in my system of classification. Eastern and southeastern Asia are especially rich in conifers (6 of 7 families plus Agathis of the seventh family, Araucariaceae, in Malaya) and those angiospermous families and subfamilies retaining many primitive features, 27 of 41 families of Magnoliidae (Magnolianae, Nymphaeanae, and Rafflesianae) and Ranunculidae (Ranunculanae) (with 7 more families in Malesia and northeastern Australia that might have migrated from southeastern Asia since the junction of the Asiatic and Australian tectonic plates, possibly 15 million years before the present). Also represented in eastern and southeastern Asia are 9 of 9 families and additional subfamilies of Hamamelidales (Rosidae) and 26 of 32 families of Alismatidae (Triuridanae, Acoranae, Aranae, Alismatanae), and Liliales (Liliidae), which seem to be the least specialized monocots. The much studied close floristic relationships between eastern Asia and eastern North America were much stronger in Cretaceous and Tertiary time. Indeed, many of the archaic genera of seed plants now restricted to eastern Asia once were widely distributed in North America and other parts of the northern hemisphere. Hence, one can state that eastern and southeastern Asia are indeed a living museum of archaic vascular plants, but fossil evidence is presently inadequate to prove that the region is the major birthplace of the conifers and flowering plants. It is probable, however, that some of the gymnosperms and archaic angiosperms did evolve in eastern and southeastern Asia, and especially in the Sino-Japanese Region.