DOI: 10.5091/plecevo.158824

Authors: Rafael F. de Almeida, Sedera Norotiana Rasambo, Kelda Elliott, Marco O.O. Pellegrini, Nivohenintsoa Rakotonirina, Tiana Randriamboavonjy, Mamy Tiana Rajaonah, Miantsa Andrianantenaina, Noro Fenitra Randrianarimanana, Nantenaina Herizo Rakotomalala, Mbola Rakotondratsimba, Sedera Ny Aina Ranaivoson, Tafitaniaina Randriatsarazaka, David Goyder, Maria S. Vorontsova

Abstract: Background and aims – Acridocarpus belongs to one of the seven Malpighiaceae lineages that dispersed from the Neotropics to the Paleotropical region, being by far the most widely diversified and distributed genus of the family in Africa. In this study, we tested the monophyly and validity of the current infrageneric classification of Acridocarpus with a dated molecular phylogeny. We also reconstructed ancestral range distributions for biomes and continents to elucidate which route led to the colonisation of Africa by the most recent common ancestor (MRCA) of this genus. Material and methods – We sampled six genes (ITS, PHYC, matK, ndhF, rbcL, and trnL-F), 21 species of Acridocarpus, and three outgroup species to test the monophyly of the infrageneric classification of the genus. BI and ML analyses were performed for the combined molecular dataset. A total of 20 morphological characters were optimised on the tree. Calibration points derived from a published Malpighiaceae chronogram were used for a dating analysis. Ancestral areas of Acridocarpus and its relatives were estimated for continental (South America, Africa, India, Madagascar, and New Caledonia) and biome (dry forests, humid forests, and savannas) ranges. Key results – The pre-existing infrageneric classification of Acridocarpus was recovered as non-monophyletic due to being solely based on homoplastic morphological characters. The MRCA of Acridocarpus colonised rainforests of East Africa + Madagascar 43 Mya via the Gondwana route and greatly diversified in this region, with a single long-distance dispersal event from Madagascar to New Caledonia (Oceania). The genus colonised African dry forests at least four different times, starting in the Oligocene and diversified a single time in Malagasy savannas in the Miocene.

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DOI: 10.5091/plecevo.115623

Authors: Truong Van Do, Ngan Thi Lu, Anh Tuan Le, Mai Xuan Thi Lam, Xuan Thi Trinh, Jean-Philippe Deguine, Thao Thi Hoang, Rafael Felipe de Almeida

Abstract: Background and aims – Vietnam is one of the leading diversity centres for Asian Malpighiaceae, comprising 24 accepted species and three native genera (i.e. Aspidopterys, Hiptage, and Tristellateia). During recent fieldwork towards completing the taxonomic revision of Malpighiaceae for the Flora of Vietnam, we have collected specimens from two populations that could not be placed in any of the three native genera of this family. We performed morphological and molecular phylogenetic studies to test the generic placement of those specimens. Material and methods – We sampled 27 genera (including the Asian Acridocarpus, Aspidopterys, Brachylophon, Hiptage, Stigmaphyllon, and Tristellateia, out of a total of 75) of Malpighiaceae representing all phylogenetic clades comprising paleotropical lineages (i.e. acridocarpoids, bunchosioids, tetrapteroids, malpighioids, and stigmaphylloids), the unusual specimen recently collected in Vietnam, and the two genera of Elatinaceae as outgroups. Maximum Likelihood analysis was carried out based on a molecular matrix alignment of the internal transcribed spacer marker (ITS). Comprehensive morphological analyses were also carried out based on the collected specimens and additional herbarium specimens. Key results – Our molecular phylogeny strongly supported the unusual specimen from Vietnam placed as sister to Hiptage in the tetrapteroid clade. Key morphological traits differing these Vietnamese specimens from Hiptage were identified related to the floral bud imbrication, shape, colour, posture of sepals and petals, length of stamen filaments, number of styles, and shape of mericarps, allowing the proposition of a new monospecific genus. Conclusions – Chlorohiptage vietnamensis is proposed as a new monospecific genus closely related to Hiptage but differing in several key morphological traits. A complete morphological description is provided alongside photographic illustrations and notes on its conservation, distribution, ecology, etymology, and taxonomy. Additionally, an updated identification key to the genera of the tetrapteroid clade is provided.

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DOI: 10.5091/plecevo.102524

Authors: Carolina Prandi da Silva, Rafael Felipe de Almeida, Talita Kely Bellonzi, Eduardo Custódio Gasparino

Abstract: Background and aims – Pollen grain morphology is an important morphological character for aiding the systematics of flowering plants. For Malpighiaceae, only a single unpublished palynological study has comprehensively sampled ca 60 of this family’s 75 currently accepted genera. To test the systematic relevance of pollen morphology in Amorimia and allies, we characterised the pollen morphology of these lineages. We scored, coded, and mapped 12 characters onto the most recent molecular phylogeny of Amorimia and allies. Material and methods – We sampled 13 species of Amorimia as ingroup and two species of Mascagnia and Ectopopterys soejartoi as outgroup. Pollen grains were acetolised, characterised, and measured using light microscopy and scanning electron microscopy. Pollen quantitative measurements were submitted to a PCA multivariate analysis. Additionally, quantitative and qualitative characters were scored and coded into 12 characters and mapped onto the molecular phylogeny of Amorimia and allies. Key results – Amorimia and allies are stenopalynous due to all species showing the same pollen type, with some subtle differences between the pollen grains, such as details of ornamentation, shape, size, and thickness of the pollen exine. However, the patterns of pollen grain evolution showed that few qualitative and apomorphic characters are informative for intrageneric distinction (i.e. type and number of apertures), and almost all quantitative and homoplastic characters analysed were informative at infrageneric levels within Malpighiaceae. Conclusion – Our results demonstrate that even though the pollen morphology characters of Amorimia and allies show subtle variation, both qualitative and quantitative apomorphic and/or homoplastic characters are highly informative for intra- and infrageneric levels in Malpighiaceae when analysed in a phylogenetic context.

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DOI: 10.5091/plecevo.101657

Authors: Rafael F. de Almeida, Isa L. de Morais, Marco O.O. Pellegrini, Cassio van den Berg

Abstract: Background and aims – Cordobia, Gallardoa, Mionandra, and Peixotoa (Stigmaphylloid clade, Malpighiaceae) are four small, closely related genera comprising shrubs or lianas endemic to South American savannas, dry forests, and temperate steppes. Their generic limits have significantly changed in the last century, and past molecular phylogenetic studies of Malpighiaceae have not tested the morphological characters of this group to identify synapomorphies supporting these clades/genera. Material and methods – We sampled the monospecific Cordobia and Gallardoa, one species of Mionandra (out of 2 spp.), nine species of Peixotoa (out of 29 spp.), and a single species of Camarea and Janusia as outgroups. Bayesian and Maximum Likelihood analyses were carried out for this clade based on five molecular markers (i.e. ETS, ITS, PHYC, matK, and ndhF). A set of 16 macromorphological characters was scored and coded for identifying synapomorphies under the Maximum Likelihood criteria. Key results – Our molecular phylogeny recovered Peixotoa as monophyletic and sister to the clade comprising Cordobia + Gallardoa + Mionandra, strongly corroborating previous phylogenetic studies of Malpighiaceae. The character-mapping analyses recovered two synapomorphies supporting the Cordobia + Gallardoa + Mionandra + Peixotoa clade, six supporting Mionandra s.l. (i.e. Cordobia + Gallardoa + Mionandra), and five supporting Peixotoa. Cordobia and Gallardoa are proposed as synonyms of Mionandra, alongside the necessary combinations, typifications, and identification keys. Conclusions – Morphological characters related to the degree of connation of the stipules, leaf indumentum type, petiole length, inflorescence architecture, number of flowers per inflorescence, presence of a peduncle in the 1-flowered cincinni, sepal connation, posture and texture, petal width and margin integrity, staminode presence, shape and size, and the shape of the apex of styles were key in circumscribing these lineages. Mionandra s.l. is proposed and characterised, including a new combination, an identification key to distinguish its species, a distribution map, and taxonomy notes.

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