Apocynoideae

Abstract: An updated suprageneric classification is provided for Apocynaceae to bring the family into better agreement with recent morphological and molecular, mainly phylogenetic-based, results. A total of 366 genera are recognized and placed within five subfamilies, 25 tribes and 49 subtribes. In Apocynaceae s. str., one new tribe (Amsonieae) and two new subtribes (Tonduziinae and Vincinae) are described in Rauvolfioideae, and one new tribe (Rhabdadenieae) and nine new subtribes (Amphineuriinae, Beaumontiinae, Chonemorphinae, Galactophorinae, Papuechitinae, Peltastinae, Pentalinoninae, Prestoniinae and Urceolinae) are described or validated in Apocynoideae. Within Asclepiadoideae, one new tribe (Eustegieae) and three subtribes (Diplolepinae, Pentacyphinae and Tassadiinae) are described or validated.

Abstract: Relationships within Apocynaceae s.l. (Apocynaceae s. str., Periplocaceae, and Asclepiadaceae) were investigated by maximum parsimony analysis of morphological and molecular sequence data. Sequences of the plastid trnL intron and trnL-F spacer for 152 accessions for representatives of all major tribes were included in this study; 96% of these sequences represent new data. Two outgroups were selected from the closely related Loganiaceae. The total evidence matrix incorporated trnL intron and trnL-F spacer sequences, insertion/deletion information, and propagule characters. The phylogenetic hypothesis derived from this data set was used to evaluate the most current classification systems and was also used to investigate trends in seed dispersal. Apocynaceae s.l. are a strongly defined monophyletic group, a finding that should be reflected in taxonomic treatments. The recognition of three of the five subfamilies proposed by Endress and Bruyns in 2000 is supported by the monophyletic Periplocoideae, Secamonoideae, and Asclepiadoideae, whereas the paraphyletic Rauvolfioideae and Apocynoideae are not supported. The precise position of the Periplocoideae, however, remains unclear. Traditional tribal delimitations were less congruent with our total evidence phylogeny. The evolution of seed comas and enhanced long-distance dispersal within the Apocynaceae s.l. probably contributed to accelerated cladogenesis, ultimately giving rise to the majority of the extant genera within the family. Phylogeographic analysis of our data provides some evidence for a Gondwanan origin of the family.

Abstract: Phylogenetic relationships were reconstructed among 59 of 77 genera of subfamily Apocynoideae and exemplars of Periplocoideae, Secamonoideae, and Asclepiadoideae (collectively the APSA clade) using sequences from four regions of the chloroplast genome (trnL intron and trnL-trnF spacer, rpl16 intron, rps16 intron, matK and 3′ half of trnK intron) and 16 morphological characters. Apocynoideae are resolved as paraphyletic. The five tribes recognized within this subfamily in the classification of Endress and Bruyns are all paraphyletic or polyphyletic. Seven major clades of Apocynoideae are identified. The first three include genera classified predominantly in tribes Wrightieae and Malouetieae sensu Endress and Bruyns and form a paraphyletic grade to a crown clade. The crown clade includes four clades of Apocynoideae genera classified in tribes Apocyneae, Mesechiteae, and Echiteae together with Periplocoideae, Secamonoideae, and Asclepiadoideae; the latter three constitute the traditional Asclepiadac...