Leonid V. Averyanov

Transfer of Villarsia cambodiana to Nymphoides (Menyanthaceae)

Abstract Specimens of Villarsia cambodiana (Menyanthaceae), the only tropical Villarsia species, were collected from Vietnam, where the species had not been recorded. Molecular data were used to evaluate the phylogenetic position of V. cambodiana relative to 31 other Menyanthaceae taxa representing 11 species of Nymphoides and every species of Liparophyllum, Menyanthes, Nephrophyllidium, Ornduffia, and Villarsia. Phylogenetic analysis of nuclear (ITS) and chloroplast (matK/trnK, rbcL) DNA data strongly supported the resolution of V. cambodiana within Nymphoides, sister to N. aurantiaca. After plotting morphological data onto the molecular phylogenetic tree, we observed that leaf and inflorescence characters associated with an erect habit, which superficially would assign V. cambodiana to Villarsia, have arisen or been lost independently in several other Menyanthaceae species representing three genera. Moreover, several characteristics of this taxon, particularly seed morphology and an inflorescence with paired pedicels, are more consistent with those of Nymphoides than of Villarsia. We thus transfer V. cambodiana to Nymphoides under the new combination Nymphoides cambodiana.

An unusual new species of Trevesia from Vietnam and its implications on generic delimitation in Araliaceae

Trevesia vietnamensis J. Wen & P.K. L?c (Araliaceae) is described as an unusual new species from northwestern Vietnam. This species has 4?5-merous flowers with a 4-5-locular ovary and palmately compound leaves and would thus fit well within Brassaiopsis morphologically. Phylogenetic analysis using the nuclear ribosomal ITS and the chloroplast ndhF and trnL-F sequences, however, clearly places the new taxon in Trevesia, defined to include species with 6-16-merous flowers with 6-16-locular ovaries, and palmately lobed simple leaves. The discovery of Trevesia vietnamensis thus blurs the generic boundary between Trevesia and Brassaiopsis. The phylogenetic analysis suggests a sister-species relationship between Trevesia vietnamensis and T. lateospina from northern Thailand, a finding supported by a shared morphological character?the presence of setose hairs on the inflorescences and young stems. Trevesia vietnamensis is restricted to two localities in northwestern Vietnam. It grows in limestone areas in valleys and on shady mountain slopes at 500-700 m in primary, tropical, monsoon, broad-leaved forests.

Diplopanax vietnamensis, a new species of (Nyssaceae) from Vietnam - one more living representative of the Tertiary Flora of Eurasia

A new species of Diplopanax, D. vietnamensis (Nyssaceae, Cornaceae s.l.), was discovered in the mountains of southern Vietnam. It differs from the single known species, Diplopanax stachyanthus, by short, simple, densely pubescent inflorescences and large yellow-white flowers with five prominent bosses on the flower disc. This genus (with two species, D. stachyanthus and D. vietnamensis) is now regarded as congeneric with Mastixicarpum, representatives of which were an integral component of the Mastixia-like paratropical broad-leaved evergreen vegetation that covered much of the Northern Hemisphere from the uppermost Cretaceous to the late Miocene, about 65 to 7 million years ago.