Phylogeny and systematics of Aponogeton (Aponogetonaceae): the Australian species

TAXON, 2010

In this paper we investigate phylogenetic relationships for Caralluma R. Br. (Apocynaceae-Asclepiadoideae-Ceropegieae), the largest genus among the stapeliads, using analyses of data from four molecular markers: two plastid regions psbA-trnH and trnT-F and two nuclear regions ITS and ncpGS. Our analyses show that the stapeliads consist of two lineages, with Caralluma dominating one of these lineages. Within this lineage, Caralluma is not monophyletic, with its species distributed among two major clades. One of these clades contains species of Caralluma and representatives of Anomalluma Plowes, Echidnopsis Hook. f. and Rhytidocaulon P.R.O. Bally, while in the other clade the small genera Edithcolea N.E. Br., Frerea Dalz. and Pseudolithos P.R.O. Bally are embedded among species of Caralluma. We discuss morphological features that characterize some of the clades. Caralluma is mainly paleotropical in its distribution and is the most widely distributed group among the stapeliads, from the Canary Islands in Macaronesia to the Indian subcontinent. We show that the Indian subcontinent has been invaded four times by species of Caralluma, while its greatest diversity is found in NorthEast Africa and southern Arabia.

Annals of the Missouri Botanical Garden, 2007

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 39 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.

Systematic Botany, 2008

The current infrafamilial taxonomy of the Iridaceae recognizes four subfamilies; Isophysidoideae (1: 1); Nivenioideae (6: ca. 92), Iridoideae (29: 890), and Crocoideae (29: 1032). Phylogenetic analyses of sequences of five plastid DNA regions, rbcL, rps4, matK, and rps16, confirm most aspects of this classification and the evolutionary patterns that they imply, importantly the sisiter relationship of Isophysidoideae to the remainder of the family and the monophyly of Iridoideae. Subfamily Nivenioideae is, however, paraphyletic; Crocoideae is consistently found nested within it, sister to the core Nivenioideae, the woody Klattia, Nivenia, and Witsenia. This clade is sister to Aristea, which in turn is sister to the Madagascan Geosiris, and then to the Australasian Patersonia. We treat Aristea, Geosiris, and Patersonia as separate subfamilies, Aristeoideae and the new Geosiridaceae and Patersonioideae, rendering Nivenioideae and Crocoideae monophyletic. The alternative, uniting a widely circumscribed Nivenioideae and Crocoideae, seems undesirable because Nivenioideae have none of the numerous synapomorphies of Crocoideae, and that subfamily includes more than half the total species of Iridaceae. Main synapomorphies of Crocoideae are: pollen operculate; exine perforate; ovule campylotropous; root xylem vessels with simple perforations; rootstock a corm; inflorescence usually a spike; plants deciduous. Four more derived features of Crocoideae are shared only with core Nivenioideae: flowers long-lived; perianth tube well developed; flowers sessile; and septal nectaries present. The genera of the latter subfamily are evergreen shrubs, have monocot-type secondary growth, tangentially flattened seeds, and the inflorescence unit is a binate rhipidium. The latter feature unites core Nivenioideae with Aristea, Geosiris, and Patersonia, which have fugaceous flowers and, with few exceptions, a blue perianth. Molecularbased phylogenetic trees using sequences from five plastid DNA regions now show discrete generic clusters within Crocoideae and Iridoideae, the foundation for the tribal classification. The five tribe classification of Iridoideae, initially based on morphological characters and subsequently supported by a four plastid DNA region sequence analysis, continues to receive support using additional DNA sequences. Application of molecular clock techniques to our phylogeny indicates that the Iridaceae differentiated in the late Cretaceous and diverged from the next most closely related family, Doryanthaceae circa 82 mya, thus during the Campanian. The Tasmanian Isophysis is the only extant member of the clade sister to the remainder of the Iridaceae, from which it may have diverged 66 mya, in the Maastrichtian. The generic phylogeny shows the proximal clades of the family are all Australasian, which corroborates past hypotheses that the Iridaceae originated in Antarctica-Australasia, although its subsequent radiation occurred elsewhere, notably in southern Africa and temperate and highland South America at the end of the Eocene or later.

Annals of the Missouri Botanical Garden, 2007

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 39 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.

Botanical Journal of the Linnean Society, 2013

In their most recent classification of Apocynaceae in 2000, Endress and Bruyns recognized five subfamilies of Apocynaceae (Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae and Asclepiadoideae). Subsequently, through various studies using molecular data, it has been shown that most tribes and subtribes of Rauvolfioideae were not monophyletic, and new tribes and subtribes have been erected to reflect improved phylogenetic understanding of the family: Aspidospermeae in Rauvolfioideae; Nerieae, Odontadenieae and Baisseeae in Apocynoideae; Fockeeae in Asclepiadoideae; and Orthosiinae in Asclepiadeae. Several genera in Rauvolfioideae have been reassigned to different tribes in order to improve the monophyly of these tribes. The sister group of Asclepiadoideae plus Secamonoideae is not Periplocoideae, as formerly assumed, but tribe Baisseeae. Periplocoideae are nested in Apocynoideae. However, tribal composition remains unclear in some parts of the family. Clade structure in Apocynaceae is now generally well understood. The principal challenges now lie in identifying characters that can reflect and articulate these clades in a formal classification. Species-rich, recent radiations such as core Asclepiadinae in Africa and the Metastematinae in Latin America present particular problems in this regard.

Taxon, 2013

Generic limits within subfamily Chrysophylloideae (Sapotaceae) from Oceania and Southeast Asia are reconciled based on a molecular phylogeny. We analysed sequences of nuclear ribosomal DNA (ETS, ITS) and the nuclear gene RPB2 with BEAST and parsimony jackknifing, using a sample of 168 terminals. Eight morphological characters were traced on a condensed majorityrule consensus tree to identify diagnostic character combinations for the genera. Accepted genera with character support are Magodendron, Pichonia, Planchonella, Pycnandra, Sersalisia, and Van-royena, while Beccariella and Niemeyera require amendment. Beccariella, a widely distributed group, is an illegitimate later homonym and we propose that the genus Pleioluma is resurrected in its place. The Australian genus Niemeyera is paraphyletic, but it is rendered monophy letic by reinstating Amorphospermum for N. antiloga. Beauvisagea, Blabeia, Fontbrunea, and Krausella are all segregates of Planchonella and rejected, while Wokoia is a later synonym of Pichonia. Planchonella baillonii, an endemic species of New Caledonia, is the sole member of an old lineage and firmly placed as the sister to a clade comprising the other congeners. Planchonella sandwicensis, a Hawaiian species, previously proposed to be a distinct genus, is a member of Planchonella. In the Pacific, P. tahitensis (including P. grayana) is a polymorphic species, widely distributed and adapted to a wide range of habitats. We provide a generic key (excluding Xantolis), diagnostic character combinations for all genera, and the necessary taxonomic combinations for Pichonia, Planchonella, Pleioluma, and Sersalisia to render each genus monophyletic.

BMC Evolutionary Biology, 2010

Background: Of the c. 450 families of flowering plants, only two are left "unplaced" in the most recent APG classification of angiosperms. One of these is the Apodanthaceae, a clade of c. 19 holoparasitic species in two or three genera occurring in North and South America, Africa, the Near East, and Australia. Because of lateral gene transfer between Apodanthaceae and their hosts it has been difficult to infer the family's true closest relatives. Results: Here we report a phylogenetic analysis of 16 accessions representing six species of Apodanthaceae from the United States, Chile, Iran, and Australia, using the mitochondrial matR gene and the nuclear 18S gene. Data matrices include 190 matR sequences from up to 95 families in 39 orders of flowering plants and 197 18S sequences from 101 families representing the 16 orders of rosids. Analyses were performed at the nucleotide and at the amino acid level. Both gene trees agree with angiosperm phylogenies found in other studies using more genes. Apodanthaceae and the seven families of the order Cucurbitales form a clade with 100% bootstrap support from matR and 56% from 18 S. In addition, the Apodanthaceae and Cucurbitales matR gene sequences uniquely share two non-synonymous codon changes and one synonymous change, as well as a codon insertion, already found by .

Systematic Botany, 2009

The Gnaphalieae are a group of sunflowers that have their greatest diversity in South America, Southern Africa, and Australia. The objective of this study was to reconstruct a phylogeny of the Australian Gnaphalieae using sequence data from the trnL intron, trnL/trnF intergenic spacer, matK, and ETS. Included in this investigation are the Australian genera of the Gnaphalieae from the subtribes Cassiniinae, Gnaphaliinae, Angianthinae, and Loricariinae, and one to four genera from all tribes of the subfamily Asteroideae to serve as outgroups. Results indicate that the subtribes Angianthinae and Cassiniinae are non-monophyletic as currently circumscribed. There is also some evidence to suggest that the genera Asteridea, Craspedia, Hyalosperma, Millotia, and Podolepis are monophyletic, whereas Calocephalus, Gnephosis, Myriocephalus pro parte, Ozothamnus, Siloxerus, Trichanthodium, and Xerochrysum are non-monophyletic. A group of perennial shrubs and alpine cushion plants from southeastern Australia dominates the clade at the base of the Gnaphalieae. The more derived clades contain primarily herbaceous annual taxa, mainly from western Australia. Based on our results, it seems likely that initial colonization and diversification of the Australian Gnaphalieae occurred in the Bassian Floristic region in eastern New South Wales, Victoria, and Tasmania. Following diversification in eastern Australia, concurrent with the increasing aridity over the entire continent during the Miocene, a massive radiation in the Gnaphalieae occurred into the arid zone of South Australia and Western Australia.

Journal of Threatened Taxa, 2021

Aponogeton lakhonensis A. Camus is rediscovered after a gap of 123 years from India. The detailed morphology of the plant along with a comparative analysis with Aponogeton natans (L.) Engler & Krause has been provided in this study supported by photographic illustrations.

TAXON, 2010

With in excess of 70 species, the Southeast Asian/Australian genus Typhonium is the largest genus of the Areae, a tribe that includes up to nine smaller genera of which Sauromatum and Lazarum have recently been reduced to the synonymy of Typhonium. To test the circumscription and relationships of Typhonium to the other Areae, we used chloroplast and nuclear DNA sequences (4319 aligned nucleotides) for 86 of the total 153 species, including representatives of all relevant genera. In the resulting phylogeny, Typhonium species fall into three well–supported clades: the first comprises most Typhonium species, including the type, T. trilobatum ; the second consists of the type of Sauromatum, S. guttatum, and other species formerly placed in that genus; the third includes only Australian endemics. Each of the remaining six genera of Areae is monophyletic. Sauromatum and Typhonium are not sister groups, requiring the recognition of Sauromatum. The Australian clade also needs to be ranked a...