No abstract

Recent botanical expeditions in central Vietnam yielded an unknown species of Annonaceae that could not be confidently identified to subfamily, tribe, and genus. Preliminary BLAST® searches based on plastid data have suggested that this taxon is genetically closely-related to the following tribes of subfamily Malmeoideae: Malmeeae, Fenerivieae, Maasieae, Phoenicantheae, Dendrokingstonieae, Monocarpieae, and Miliuseae. Using representatives of Piptostigmateae, another tribe of Malmeoideae, as outgroups and including representatives of all other tribes of Malmeoideae, molecular phylogenetic analyses of seven combined plastid markers (rbcL, matK, ndhF, ycf1 exons; trnL intron; trnL-trnF, psbA-trnH intergenic spacers) inferred the enigmatic Vietnamese taxon as belonging to the monotypic tribe Monocarpieae. Detailed morphological comparisons between this taxon and its sister group, Monocarpia Miq., warranted the recognition of a second genus of Monocarpieae to accommodate our unknown taxon: Leoheo Chaowasku with a single species, Leoheo domatiophorus Chaowasku, D.T. Ngo & H.T. Le. The morphology of the new genus agrees well with the diagnostic traits of Monocarpieae, e.g., a percurrent tertiary venation of the leaves, a highly reduced number of carpels per flower, enlarged and lobed stigmas, multiple ovules/seeds per ovary/monocarp, considerably large monocarps with a hardened pericarp when dry, and spiniform ruminations of the endosperm. However, the new genus does not exhibit two characteristic features of Monocarpia: terminal inflorescences and generally distinct intramarginal leaf veins. In addition, the new genus possesses three autapomorphic characters: hairy domatia on the lower leaf surface, longitudinal ridges on the monocarp surface, and subsessile monocarps with a stout stipe. The tribe Monocarpieae is consequently enlarged to include the genus Leoheo. The enlarged Monocarpieae, along with the recently established monotypic tribe Phoenicantheae and two other related tribes, Dendrokingstonieae and Miliuseae, are discussed.

The generic status of Winitia Chaowasku (Annonaceae Juss., Miliuseae Hook.f. & Thomson) is reaffirmed by an extensive phylogenetic reconstruction using seven plastome regions (matK, ndhF, rbcL, ycf1 exons; trnL intron; psbA-trnH, trnL-trnF intergenic spacers) and including, among others, seven accessions of Winitia plus two accessions of its sister group, Stelechocarpus Hook.f. & Thomson. The results disclosed a maximally supported clade of Winitia, as well as of Stelechocarpus. The sister relationship of the two genera is still rather poorly supported and the branch uniting them is very short, whereas the branches leading to Winitia and to Stelechocarpus are relatively long, corresponding to their considerable morphological differences. Additionally, in Miliuseae there is a particular indel of eight continuous base pairs in the trnL-trnF intergenic spacer potentially diagnostic for generic discrimination, i.e., members in the same genus possess the same indel structure (absence or presence of a gap), and this indel differentiates Winitia from Stelechocarpus. Winitia cauliflora (Scheff.) Chaowasku appears polyphyletic and Winitia longipes (Craib) Chaowasku & Aongyong comb. nov. based on Stelechocarpus longipes Craib is consequently proposed. Furthermore, our phylogenetic data support a new species, Winitia thailandana Chaowasku & Aongyong sp. nov. from southern Thailand, which is described and illustrated. A key to genera in the sageraeoid clade (Sageraea-Winitia-Stelechocarpus) and a key to the four species of Winitia are provided.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

On the basis of expansive molecular phylogenetic analyses of the genus Miliusa (Annonaceae) utilising up to seven plastid DNA regions, four major clades are identified: clades A, B, C and D. Members of clade C possess axillary inflorescences and crescent-shaped to semicircular glandular structures at the base or (slightly) higher inside the inner petals. In this clade, accessions of M. mollis are recovered as a monophyletic group, divided into two major clades. One of them is recognised as a new species, M. microphylla, which differs from the other (M. mollis) in the following characters: pedicel length, as well as glandular structures and indumentum on the inner petals. The new species is endemic to southeastern Thailand, whereas M. mollis has a much wider distribution (central, eastern, northeastern, northern and peninsular Thailand plus Cambodia and Vietnam). In addition, M. glandulifera, a new record for Thailand, is retrieved as the sister group of a clade composed of M. microphylla and M. mollis. The name M. glandulifera is lectotypified and the description of M. glandulifera is emended, with the information on mature monocarps added. The conservation status of M. microphylla and M. glandulifera is provisionally assessed. A revised key to the species in clade C in Thailand is provided. The phylogenetic position of M. nakhonsiana and M. sessilis in clade C, as well as of M. chantaburiana and M. eupoda in clade B is confirmed for the first time.