Mary E. Endress

A revised classification of the Apocynaceae s.l.

The Asclepiadaceae, as traditionally defined, have repeatedly been shown to be an apomorphic derivative of the Apocynaceae. It has often been recommended that the Asclepiadaceae be subsumed within the Apocynaceae in order to make the latter monophyletic. To date, however, no comprehensive, unified classification has been established. Here we provide a unified classification for the Apocynaceae, which consists of 424 genera distributed among five subfamilies: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae, and Asclepiadoideae. Keys to the subfamilies and tribes are provided, with lists of genera that (as far as we have been able to ascertain) are recognized in each tribe.ZusammenfassungEs wurde wiederholt festgestellt, dass die Asclepiadaceae in der traditionellen Umgrenzung ein apomorphes Derivat der Apocynaceae sind. Deshalb wurde oft vorgeschlagen, sie bei den Apocynaceae unterzubringen, damit die Apocynaceae eine monophyletische Gruppe darstellen. Bis jetzt wurde aber keine eingehende kombinierte Klassifikation publiziert. Hier stellen wir eine kombinierte Klassifikation vor für die Apocynaceae, mit 424 Gattungen, die in fünf Unterfamilien gegliedert sind: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae und Asclepiadoideae. Schlüssel zu den Unterfamilien sowie den Triben werden gegeben. Die Gattungen, die zu jeder Tribus gehören (soweit bekannt) werden aufgelistet.

PHYLOGENY OF APOCYNOIDEAE AND THE APSA CLADE (APOCYNACEAE S.L.)1

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 Asclepiadaceae. Asclepiadaceae are resolved as polyphyletic, although the node that precludes a paraphyletic Asclepiadaceae does not have bootstrap support. The clade of Secamonoideae–Asclepiadoideae is well supported as sister to a clade of three African Apocynoideae genera (Baissea A. DC., Motandra A. DC., and Oncinotis Benth.). There is a strong correlation between geographic distribution and phylogeny among crown clade Apocynoideae. A New World clade is composed of American genera plus the predominantly Australasian Parsonsia R. Br. and Artia Guillaumin. An Asian clade is composed of Asian, Malesian, and Australasian genera plus the north temperate Apocynum L. Trachelospermum Lem. is polyphyletic with American and Asian species nested in the New World and Asian clades, respectively. The implications of this phylogeny for the evolution of pollen aggregation and mass transfer, the traits that were used to separate Asclepiadaceae from Apocynaceae s. str., are discussed.

PHYLOGENY AND SYSTEMATICS OF THE RAUVOLFIOIDEAE (APOCYNACEAE) BASED ON MOLECULAR AND MORPHOLOGICAL EVIDENCE1

Abstract To elucidate deeper relationships within Rauvolfioideae (Apocynaceae), a phylogenetic analysis was conducted using sequences from five DNA regions of the chloroplast genome (matK, rbcL, rpl16 intron, rps16 intron, and 3′ trnK intron), as well as morphology. Bayesian and parsimony analyses were performed on sequences from 50 taxa of Rauvolfioideae and 16 taxa from Apocynoideae. Neither subfamily is monophyletic, Rauvolfioideae because it is a grade and Apocynoideae because the subfamilies Periplocoideae, Secamonoideae, and Asclepiadoideae nest within it. In addition, three of the nine currently recognized tribes of Rauvolfioideae (Alstonieae, Melodineae, and Vinceae) are polyphyletic. We discuss morphological characters and identify pervasive homoplasy, particularly among fruit and seed characters previously used to delimit tribes in Rauvolfioideae, as the major source of incongruence between traditional classifications and our phylogenetic results. Based on our phylogeny, simple style-heads, syncarpous ovaries, indehiscent fruits, and winged seeds have evolved in parallel numerous times. A revised classification is offered for the subfamily, its tribes, and inclusive genera.

Advances in apocynaceae : The enlightenment, an introduction

Abstract This issue of the Annals of the Missouri Botanical Garden is devoted to advances in the Apocynaceae s.l. and is based on the symposium, “Recent Progress in the Systematics of Apocynaceae,” held at the XVII International Botanical Congress in Vienna in 2005. The collection of papers presented here spans the phylogenetic and geographic breadth of the family and includes at least one study focused on representatives from each of the five subfamilies: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae, and Asclepiadoideae. The papers range from higher-level phylogenetic analyses to more narrowly defined case studies and include new results in phylogenetics, taxonomy, biogeography, pollination biology, and a pharmacophagous plant–butterfly interaction involving pyrrolizidine alkaloids, as well as a new hypothesis for the evolution of pollinia and loss of a compitum in some advanced taxa. An updated classification scheme of the Apocynaceae is presented, with one additional tribe recognized in Rauvolfioideae (the Aspidospermeae) and three in Apocynoideae (the Nerieae and Odontadenieae as well as the Baisseeae, which are elevated in rank here). In Asclepiadoideae, seven subtribes are recognized within Asclepiadeae (the Asclepiadinae, Cynanchinae, Tylophorinae, Metastelmatinae, Orthosiinae, Oxypetalinae, and Gonolobinae) and four within Ceropegieae (the Anisotominae, Leptadeniinae, Heterostemminae, and Stapeliinae). Taken together, the papers here present the most up-to-date overview of the family available at this time.

Morphology and molecular data in phylogenetic fraternity: The tribe Wrightieae (Apocynaceae) revisited

The monophyly and classification of the tribe Wrightieae of the subfarnily Apocynoideae (Apocynaceae) are cladistically investigated. Nine taxa from the Wrightieae sensu Leeuwenberg, nine from other Apocynoideae sensu lato (s.I., including two from the traditional Asclepiadaceae), and two outgroup taxa from the Plumerioideae (Apocynaceae) were scored for rcbL sequence data and morphological data, mainly floral characters, and analyzed using successive weighting parsimony analysis. The Wrightieae sensu Leeuwenberg are shown to be largely paraphyletic, the constituent taxa being dispersed among four monophyletic clades. Previously not suggested relationships indicated by the study are the association of Pachypodium with Funtumia, Holarrhena, and Mascarenhasia and the position of Beaumontia close to Trachelospermum. A reclassification of the Wrightieae is discussed, in which three of the identified clades are recognized as tribes, the Wrightieae sensu stricto (s.s.), the Nerieae, and the Malouetieae. The support for the Wrightieae s.s. is very strong, as evaluated with Bremer support and bootstrap analysis. The Malouetieae are also strongly supported, but the Nerieae less so. Using Potential morphological synapomorphies identified in the study, circumscription of the tribes is discussed. A potential pseudogene of rcbL is reported tot Beaumontia.

On the Relationship of the Apocynaceae and Periplocaceae

Abstract It is generally agreed that the Periplocaceae arose from apocynaceous ancestors. Whether these ancestors were from the Plumerioideae, Cerberoideae or Apocynoideae has long been in dispute. This investigation is a comparative study of the pollen morphology and floral structure of selected genera of Apocynaceae and Periplocaceae. The examinded genera of the Plumerioideae and the Cerberoideae have 3-colporate, smooth to sculptured pollen grains. In the Apocynoideae there are single, smooth, 2–3-porate pollen grains or 3-to multiporate grains loosely united in tetrads of variable size and shape. The exine consists of an outer thick, homogeneous stratum subtended by a very thin, granular-fibrillar stratum, and globules; the internal septa are double-layered due to partial fusion of the tecta of the individual grains. The genera of Periplocaceae have pollen grains united in elongated, rhomboidal to rounded, or tetrahedral and decussate tetrads with few to many pores, pairwise, opposite or irregularly a...

IS MANDEVILLA (APOCYNACEAE, MESECHITEAE) MONOPHYLETIC? EVIDENCE FROM FIVE PLASTID DNA LOCI AND MORPHOLOGY1

Abstract In order to test the monophyly of Mandevilla Lindl., the largest genus in tribe Mesechiteae (Apocynaceae, Apocynoideae), and its affinities to other genera in the tribe, maximum parsimony analysis was conducted on a data set comprising DNA sequences from five plastid loci (rpl16, rps16, and trnK introns; trnSGCU-trnGUUC intergenic spacer; and matK gene), as well as morphological data for 65 taxa of Mesechiteae (48, Mandevilla) and nine taxa from other tribes of the subfamily. Mandevilla, as circumscribed by Pichon, was found to be monophyletic, whereas Woodsons circumscription proved to be polyphyletic. Thus defined, Mandevilla forms a strongly supported clade that can be divided into six clades of species groups. Most of the infrageneric taxa of Mandevilla proposed by Woodson and Pichon are polyphyletic. Many of the diagnostic characters previously used to define taxonomic groups are shown to have arisen multiple times, rendering them unsuitable for classificatory purposes. The similar growth form and tubular flowers of Macrosiphonia Müll. Arg. and Telosiphonia (Woodson) Henr., two geographically disjunct segregates, represent the most extreme case of parallel evolution within Mandevilla, with their striking similarities most likely correlated to colonization of open, dry habitats and pollination by hawkmoths.

Tribal and intergeneric relationships of Mesechiteae (Apocynoideae, Apocynaceae): evidence from three noncoding plastid DNA regions and morphology

The Neotropical tribe Mesechiteae (Apocynaceae) is currently considered to include nine genera: Allomarkgrafia, Galactophora, Macrosiphonia, Mandevilla, Mesechites, Quiotania, Secondatia, Telosiphonia, and Tintinnabularia. Tribal and intergeneric relationships, however, are in dispute. To test the monophyly of the tribe and evaluate intratribal relationships, a maximum parsimony analysis was conducted based on DNA sequences from the plastid rpl16 intron, rps16 intron, and trnS-G intergenic spacer region as well as morphological data for 23 taxa of Mesechiteae and 11 taxa from other tribes of Apocynoideae. Mesechiteae, as currently circumscribed, was found to be polyphyletic. Only removal of Secondatia and Galactophora and inclusion of Forsteronia rendered the tribe monophyletic. Thus defined, Mesechiteae forms a strongly supported clade including seven genera in three subclades: the Mesechites subclade (comprising Tintinnabularia, Allomarkgrafia, and Mesechites), the Forsteronia subclade (containing only Forsteronia) and the Mandevilla subclade (comprising Macrosiphonia, Mandevilla, and Telosiphonia). Allomarkgrafia is nested in Mesechites. Macrosiphonia and Telosiphonia form two distinct monophyletic clades. Both, however, are nested in Mandevilla. Results suggest upholding the following genera in Mesechiteae: Allomarkgrafia, Forsteronia, Mandevilla, Mesechites, and Tintinnabularia. The status of Quiotania could not be evaluated.

The tribal position of Fockea and Cibirhiza (Apocynaceae: Asclepiadoideae): evidence from pollinium structure and cpDNA sequence data

The pollinium morphology of the two members of the Asclepiadoideae, tribe Fockeeae, Fockea Endl. and Cibirhiza Bruyns, has been studied in detail and compared with that of eight genera of Marsdenieae, the tribe in which Fockea and Cibirhiza were previously accommodated and thus their putative closest relatives, as well as nine genera of Asclepiadeae. Both Fockea and Cibirhiza have several morphological characteristics in common, the most important of which is the absence of well-developed caudicula, which distinguishes them from all other genera of Asclepiadoideae known. The pollinium structure of these two genera, however, differs significantly. Whereas the pollinium of Cibirhiza consists of single pollen grains and is covered by a pollinium wall, as is typical for other Asclepiadoideae, the pollinium of Fockea consists of tetrads and is not covered by a pollinium wall, a condition otherwise typical of Secamonoideae. Fockea, however, has only two pollinia per anther, as does Cibirhiza and all other Asclepiadoideae, whereas the Secamonoideae have four pollinia per anther. Sequence data from two intergenic spacers, trnT-L and trnL-F and the trnL intron of cpDNA was analyzed. The ingroup included three species of Fockea and one species of Cibirhiza. The outgroup taxa consisted of three representatives each of Periplocoideae, and Secamonoideae and 24 species of Asclepiadoideae, including representatives of all tribes, of which eight genera belong to Marsdenieae, as outgroups. The results of the DNA analysis provide strong support for Fockeeae as a monophyletic tribe, distinct from Marsdenieae and, to the rest of the Asclepiadoideae. With the exception of pollen data, all morphological and molecular evidence clearly support recognition of the tribe Fockeeae. The occurrence of two such significantly different types of pollinia structure – characters elsewhere in the family used to distinguish subfamilies – within the small tribe Fockeeae was unexpected, and can perhaps best be understood as yet another attestment to the basal position of the Fockeeae in the nascence of the Asclepiadoideae.

New Combinations in Mandevilla Lindley (Apocynaceae)

ABSTRACT Historically, taxonomic delimitation of Mandevilla Lindley, a large Neotropical genus of Apocynaceae, has been controversial. Two competing classifications were proposed by Woodson (1933) and Pichon (1948), the former now being widely accepted by taxonomists in the family. Recent phylogenetic studies, however, support the monophyly of Mandevilla sensu Pichon rather than sensu Woodson, the latter being paraphyletic with respect to Quiotania Zarucchi, Macrosiphonia Müller Argoviensis, and Telosiphonia (Woodson) Henrickson. Based on the principle of monophyly, we here re-establish Pichons classification and include Quiotania, Macrosiphonia, and Telosiphonia as synonyms of Mandevilla. Three new combinations are made here: Mandevilla hesperia (I. M. Johnston) A. O. Simões, L. S. Kinoshita-Gouvêa & M. E. Endress, M. nacalpulensis (Felger & Henrickson) A. O. Simões, L. S. Kinoshita-Gouvêa & M. E. Endress, and M. undulata (C. Ezcurra) A. O. Simões, L. S. Kinoshita-Gouvêa & M. E. Endress; Q. colombiana Zarucchi is newly synonymized with M. ligustriflora Woodson; and a lectotype is designated for M. martii (Müller Argoviensis) Pichon.