Perianth evolution in the early-divergent family Annonaceae

Main Theme: Contributions of Flora Malesiana to the Welfare of People in AsiaOral Presentation - Session 1: Taxonoly & Biosystematic-1Despite the considerable taxonomic diversity of the Annonaceae, floral structure in the family is remarkably uniform in its underlying ‘Bauplan’: Annonaceae flowers are characterised by three perianth whorls (sepals, outer petals and inner petals), with three organs per whorl; and a floral vascular system in which the traces feeding the perianth organs are basally fused. The Annonaceae are of particular phylogenetic interest as they show several apomorphic characteristics, including a differentiated (dipartite) peri...postprin

Goniothalamus tripetalus (Lam.) Veldk. & R.M.K. Saunders (Annonaceae), comb. nov.

J. F. VELDKAMP & R. M. K. SAUNDERS. 2010. Goniothalamus tripetalus (Lam.) Veldk. & R. M. K. Saunders (Annonaceae), comb. nov. Reinwardtia 13(2): 167–169. — Goniothalamus tripetalus (Lam.) Veldk. & R. M. K. Saunders (Annonaceae) is a new combination.published_or_final_versio

Reassessing morphological homologies in the early-divergent angiosperm Fenerivia (Annonaceae) based on floral vascular anatomy: significance for interpreting putative homeotic mutations

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Generic monophyly and floral morphology of Disepalum (Annonaceae): investigating a possible evolutionary shift in pollination system

Poster: no. 4Taxonomic opinion regarding the delimitation of Disepalum (Annonaceae) has been divided: some researchers recognise a broadly circumscribed genus, characterised by pollen grains that develop in octads, and monocarps that are borne on an elongated ‘carpophore’; whilst others adopt a narrower delimitation (characterised by a calyx of only two sepals, and a fused corolla), with three species segregated in the genus Enicosanthellum (with three sepals, and unfused petals, as in most Annonaceae). Previous morphological research (Johnson, 1989) included hypo...postprin

Floral biology and pollination ecology of Desmos chinensis (Annonaceae): assessing the efficacy of floral synchrony for promoting xenogamy

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Phylogenetic Reconstruction, Morphological Diversification and Generic Delimitation of Disepalum (Annonaceae)

Taxonomic delimitation of Disepalum (Annonaceae) is contentious, with some researchers favoring a narrow circumscription following segregation of the genus Enicosanthellum. We reconstruct the phylogeny of Disepalum and related taxa based on four chloroplast and two nuclear DNA regions as a framework for clarifying taxonomic delimitation and assessing evolutionary transitions in key morphological characters. Maximum parsimony, maximum likelihood and Bayesian methods resulted in a consistent, well-resolved and strongly supported topology. Disepalum s.l. is monophyletic and strongly supported, with Disepalum s. str. and Enicosanthellum retrieved as sister groups. Although this topology is consistent with both taxonomic delimitations, the distribution of morphological synapomorphies provides greater support for the inclusion of Enicosanthellum within Disepalum s.l. We propose a novel infrageneric classification with two subgenera. Subgen. Disepalum (= Disepalum s. str.) is supported by numerous synapomorphies, including the reduction of the calyx to two sepals and connation of petals. Subgen. Enicosanthellum lacks obvious morphological synapomorphies, but possesses several diagnostic characters (symplesiomorphies), including a trimerous calyx and free petals in two whorls. We evaluate changes in petal morphology in relation to hypotheses of the genetic control of floral development and suggest that the compression of two petal whorls into one and the associated fusion of contiguous petals may be associated with the loss of the pollination chamber, which in turn may be associated with a shift in primary pollinator. We also suggest that the formation of pollen octads may be selectively advantageous when pollinator visits are infrequent, although this would only be applicable if multiple ovules could be fertilized by each octad; since the flowers are apocarpous, this would require an extragynoecial compitum to enable intercarpellary growth of pollen tubes. We furthermore infer that the monocarp fruit stalks are likely to have evolved independently from those in other Annonaceae genera and may facilitate effective dispersal by providing a color contrast within the fruit.published_or_final_versio

A new species of Goniothalamus (Annonaceae) from Palawan, and a new nomenclatural combination in the genus from Fiji

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Historical biogeography and ecological niche modelling of the Asimina-Disepalum clade (Annonaceae): role of ecological differentiation in Neotropical-Asian disjunctions and diversification in Asia

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Historical biogeography of Asimina-Disepalum (Annonaceae): origins of tropical intercontinental disjunctions and diversifications in Southeast Asia

Oral Session: Secondary forestsStudies of tropical intercontinental disjunctions, common biogeographical patterns in flowering plants, enable insights into the origin of extant distributions and diversity patterns. We investigate the temporal origin of the Neotropical-Asian disjunction in the Asimina-Disepalum clade of the early-divergent angiosperm family Annonaceae, and temporal congruence with underlying palaeoclimatic and geological processes. Moreover, we aim to identify the geographical origin of Disepalum, and to infer dispersal and vicariance events as well as potentially correlated climate niche differentiation in the evolution of the genus in …postprin

Reproductive resource partitioning in two sympatric Goniothalamus species (Annonaceae) from Borneo: floral biology, pollinator trapping and plant breeding system

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