Phylogeny of theAsterales sensu lato based onrbcL sequences with particular reference to theGoodeniaceae

TherbcL gene of 25 taxa was sequenced and analyzed cladistically in order to define more precisely the orderAsterales s.l. and to reconstruct the phylogeny ofGoodeniaceae. The cladistic analyses show that theAsterales comprise the familiesAbrophyllaceae, Alseuosmiaceae, Argophyllaceae, Asteraceae, Calyceraceae, Campanulaceae s.l.,Donatiaceae, Goodeniaceae (includingBrunoniaceae),Menyanthaceae, Pentaphragmataceae, andStylidiaceae. Abrophyllaceae, Alseuosmiaceae, Brunoniaceae, andDonatiaceae have previously not been studied in this respect. Within theGoodeniaceae, four groups supported by therbcL data can be distinguished: the genusLechenaultia, theAnthotium-Dampiera-group, the genusBrunonia, and a group formed by the remaining genera, theScaevola-Goodenia-group.     

rbcL sequences support exclusion ofRetzia,Desfontainia, andNicodemia from theGentianales

The taxonomic positions ofRetzia, Desfontainia, andNicodemia have been much discussed, and all three genera have been included inLoganiaceae (Gentianales). We have made a cladistic analysis ofrbcL gene sequences to determine the relationships of these taxa toGentianales. Four newrbcL sequences are presented; i.e., ofRetzia, Desfontainia, Diervilla (Caprifoliaceae), andEuthystachys (Stilbaceae). Our results show thatRetzia, Desfontainia, andNicodemia are not closely related toLoganiaceae or theGentianales. Retzia is most closely related toEuthystachys and is better included inStilbaceae. The positions ofDesfontainia andNicodemia are not settled, butDesfontainia shows affinity for theDipsacales s.l. andNicodemia for theLamiales s.l.     

The phylogenetic relationships ofByblis andRoridula (Byblidaceae-Roridulaceae) inferred from partial 18S ribosomal RNA sequences

The phylogenetic relationships of the angiosperm generaByblis andRoridula have been the subject of ongoing taxonomic controversy. Twenty-eight taxa of varying degrees of alleged relationship, including 3 members of theWinteraceae (as an outgroup), were investigated using partial sequences of 18S rRNA (small subunit) and also compared against the morphological data set fromHufford's (1992) cladistic treatment of 80 members of theRosidae-Asteridae. The morphological analysis placed the two genera in a clade with theSarraceniaceae in theCorniflorae-Asterid group as a sister taxon to anEricales-Hydrangeales clade. The 18S rRNA analysis supports the recently publishedrbcL DNA analysis ofAlbert & al. (1992), withRoridula joined to taxa in the lowerRosidae, butByblis joining instead to members of theAsteridae near theSolanaceae. Comparisons for congruence between the three analyses placeByblis in the higher Asterid group near theSolanaceae, andRoridula possibly nearer theSarraceniaceae andEricales. These results imply that the traditional morphological characters used to relate the two genera are possibly the result of convergence towards similar ecological and life-history strategies rather than synapomorphies.     

Heliantheae sensu lato (Asteraceae), clades and classification

The interrelationships within theHeliantheae s. lato and the closely relatedEupatorieae are analyzed and discussed. The basis to this discussion is a cladistic analysis of 141 morphological characters (172 apomorphic states) scored for 97 genera. TheHeleniae s. lato, a subgroup of theHeliantheae s. lato, are paraphyletic, and a monophyletic group corresponding largely to theHeliantheae s. str. is recognized. TheEcliptinae sensuRobinson are polyphyletic. TheCoreopsidinae form an ingroup in theHeliantheae s. str. TheTageteae (Pectidinae) and theMadieae (Madiinae) are two separate branches within the helenioid assemblage of taxa.     

Phylogenetic relationships of theJuglandaceae

A cladistic analysis of molecular data from the chloroplast generbcL was used to examine the taxonomic relationships of the walnut family (Juglandaceae). In addition, chemical and morphological data from a previous study byHufford (1992) were incorporated, expanded, and analyzed independently and in combination with the molecular data. The results of these analyses suggest that theJuglandaceae are more closely related to theFagaceae, Betulaceae, Casuarinaceae, andUrticaceae and their relatives (sensuCronquist 1981) than they are to theAnacardiaceae (sensuThorne 1983). However, sequence data fromrbcL also suggest a relationship between the higherHamamelidae and certain families in theRosidae sensuCronquist 1981 (such asRosaceae andRhamnaceae), an outcome which would add credence to the widely accepted view of the polyphyletic nature of theHamamelidae.     

Leaf flavonoid chemistry and the relationships of theLactoridaceae

Leaves of the monotypic angiosperm familyLactoridaceae exhibit flavonoid constituents consisting of six 3-0-diglycosides of the flavonols kaempferol and isorhamnetin. The presence of flavonols is concordant with the placement ofLactoridaceae among the archaic or primitive flowering plants. Flavonoid chemistry is less informative on the relationships of the family within the primitive dicots. The presence of isorhamnetin suggests closer affinities with families in theLaurales, particularly theGomortegaceae andMonimiaceae. Phenetic and cladistic analyses of morphological features place theLactoridaceae near several families in theMagnoliales.     

A search for the phylogenetic position of the seven-son flower (Heptacodium, Dipsacales): Combining molecular and morphological evidence

A first report on the problematic phylogenetic position ofHeptacodium (2 spp.; China) using molecular data from chloroplast DNA is presented. Amplification of ORF2280 homolog region was executed in a number of representative taxa in order to determine ifHeptacodium shows similar structural rearrangements as other Dipsacales. DNA sequences ofndhF were generated to clarify the phylogenetic position ofHeptacodium among Caprifoliaceae (s.l.). Six outgroup taxa and fifteen representatives of Dipsacales were sampled and more than 2100 basepairs ofndhF sequence were used in a cladistic analysis. Parsimony analysis produced two shortest trees and showedHeptacodium as sister to all members of Caprifoliaceae (s.str.), although weakly supported. Additionally, trees were constructed withndhF data supplemented with availablerbcL sequences and a morphological data set. Results of all analyses support an unresolved basal position forHeptacodium among Caprifoliaceae (s.l.), which in part explains the difficulty experienced previously in classifying the genus.     

The phylogeny and evolution of thePterygodium—Corycium complex (Coryciinae,Orchidaceae)

The leaf-anatomy, palynology, seed-morphology, vegetative morphology and especially the highly complicated floral morphology of theCoryciinae s. str. (Diseae: Orchidoideae: Orchidaceae) are described and illustrated in detail. On the basis of these characters the presumed phylogeny, based on a rigorous cladistic analysis, is presented. The cladistic biogeographical analysis of theCoryciinae s. str. shows that it is a member of the Afrotemperate Track, with a pattern of vicariance events typical of the members of this track. An analysis of the patterns of speciation shows that allopatric speciation appears to be rare, and that parapatric speciation across edaphic boundaries may be the most important factor. Proceeding from the information presented, a new classification of the group is proposed in which we recognize the four generaCeratandra, Evotella, Pterygodium andCorycium. The new monotypic genusEvotella comprises a species originally described asPterygodium rubiginosum. The three species of the genusAnochilus are transferred toCorycium andPterygodium. P. magnum, which was originally described asPterygodium but was transferred toCorycium lately, is placed in a monotypic section ofPterygodium.     

Cladistic interrelationships and major clades of theEricales

A cladistic analysis of theEricales based on morphological, anatomical, embryological, and phytochemical data has been undertaken. Resulting from the analysis, 56 equally parsimonious cladograms were obtained. The tribeEnkiantheae was found to be the sister-group of the rest of theEricaceae, in which theEmpetraceae, theEpacridaceae, Pyrolaceae, andMonotropaceae are forming derived ingroups. It is thus concluded that theEricaceae are a paraphyletic assemblage as presently circumscribed, and thatEmpetraceae andEpacridaceae are better treated as members of theEricaceae.     

Relationships, circumscription, and biogeography of Arcytophyllum (Rubiaceae) based on evidence from cpDNA

A cladistic analysis was performed using nucleotide sequence variation in therps16 intron and thetrmL-F region (plastid DNA).Arcytophyllum belongs in a subclade of the tribe Spermacoceae (s.l.) together with the American species presently classified in the generaHedyotis andHoustonia. This subclade is morphologically characterized by cymbiform seeds.Arcytophyllum is the sister group of all AmericanHedyotis andHoustonia and it is suggeste that these latter would be most conveniently treated as a single genus, the correct name of which would beHoustonia.Arcytophyllum should be circumscribed such that it excludesA. serpyllaceum, which is not a member of theArcytophyllum-Houstonia clade but more closely related toBouvardia. The phylogeny that was reconstructed suggests that the ancestral area of theArcytophyllum-Houstonia clade is the South American tectonic plate.     

Relationships in theAcanthaceae and related families as suggested by cladistic analysis ofrbcL nucleotide sequences

A parsimony analysis of DNA sequences of the chloroplast-encoded generbcL from twelve members of theAcanthaceae s.l., including members of the sometimes segregateThunbergioideae andNelsonioideae, and other families in theBignoniales sensuThorne (1992) is presented. The results largely agree with the classification of theAcanthaceae presented byBremekamp (1965) andThorne (1992) and supportNelsonioideae as a sister group to the rest of theAcanthaceae. Thunbergioideae are placed as a sister toAcanthaceae s.str.Acanthus andAphelandra, both representatives ofAcanthoideae, form a sister group toRuellioideae. An analysis of branch support found that many branches throughout theBignoniales are weakly upheld. This points to the need for further studies in the group using more sequences ofrbcL as well as other data. None of the families ofBignoniales as presently circumscribed (includingAcanthaceae s.l.) were strongly supported, although the larger clade containing the families of theBignoniales was robust.     

Phylogenetic relationships of Scaphyglottis and related genera (Laeliinae: Orchidaceae) based on nrDNA ITS sequence data

Sequences of the nuclear ribosomal internal transcribed spacer regions 1 & 2 (nrDNA ITS) including the intervening 5.8S region were analyzed cladistically for 43 individuals of 35 species ofScaphyglottis s.l. plus two outgroup taxa. Low levels of sequence divergence do not allow estimation of relationships among most clades, but the analyses indicate that four segregate genera (Hexisea Lindl.,Reichenbachanthus Barb. Rodr.,Hexadesmia Brogn., andPlatyglottis coriacea L.O. Williams) are embedded within a broad paraphyleticScaphyglottis. This broadly definedScaphyglottis sensu Dressler is characterized within Laeliinae by the usual presence of superposed growth habit and the presence of a column foot. In order to accommodate species formerly placed inPlatyglottis andReichenbachanthus, three new combinations are made inScaphyglottis:Scaphyglottis brasiliensis (Schltr.) Dressler,S. coriacea (L. O. Williams) Dressier, andS. emarginata (Garay) Dressler.     

Molecules and morphology: Congruence of data inColumnea (Gesneriaceae)

The cladistic analysis and comparison of molecular and morphological data has been the source of much recent debate. In this study, independent analyses of molecular and morphological data fromColumnea L. sects.Pentadenia andStygnanthe (Gesneriaceae) are compared. Comparative methods include consensus, visually comparing trees from independent analyses and combined data analysis. Consensus methods provided little resolution. Comparison of trees obtained from the independent analyses revealed some differences although the trees are highly similar. However, a combined analysis found that the level of incongruence between the two data sets was low. The tree resulting from the combined data has aspects of both the morphological and molecular trees despite the larger number of molecular characters. In addition, the combined data tree has greater resolution than either of the two data sets singly, indicating that the two types of data are congruent, and complementary to each other.     

Cladistic analyses of some net-veinedLiliiflorae

Comparisons between previous intuitive or phenetic classifications of the netveinedLiliiflorae was used to determine a suitable group of taxa for cladistic analyses. The resultant 48 genera and generic groupings comprising 19 families from within theAsparagales, Liliales andDioscoreales were then analysed. The cladistics largely supported previous treatments, with theLiliales, Dioscoreales andAsparagales all monophyletic.Invited paper, 14th International Botanical Congress, Berlin, Symposium on theory and practice of botanical classification, July 1987.     

Implications ofrbcL sequence data for higher order relationships of theLoasaceae and the anomalous aquatic plantHydrostachys (Hydrostachyaceae)

Subclass and ordinal relationships ofLoasaceae, a small predominately New World family, are examined usingrbcL sequence data. Sequences were examined for eight of the fifteen genera of theLoasaceae and the morphologically anomalous aquatic genusHydrostachys (Hydrostachyaceae). Parsimony analyses of these sequences, combined with previously publishedrcbL data, indicate thatLoasaceae belong in theCornales, and are the sister group ofHydrangeaceae. This agrees with phylogenies based on chloroplast DNA inverted repeat restriction site, morphological and chemical data. TherbcL trees support the monophyly of theLoasaceae and most generic relationships correspond to current subfamily divisions. TherbcL phylogeny also provides the first suggestion thatHydrostachys is allied with theHydrangeaceae in theCornales.     

The familial and subfamilial relationships ofApocynaceae andAsclepiadaceae evaluated withrbcL data

Sequence data for therbcL gene from twenty-four taxa of the familiesApocynaceae andAsclepiadaceae were cladistically analysed in order to evaluate the existing familial and subfamilial classification. The taxa sampled represent all described subfamilies and a majority of the described tribes. The cladistic analysis shows that theAsclepiadaceae are nested within theApocynaceae. An amalgamation of the two families is therefore recommended. The subfamilial classification is also in need of revision: the subfamiliesPlumerioideae andApocynoideae of the current classifications are paraphyletic, as are many of the tribes. Potential subfamily candidates and characters traditionally used in the classification are discussed.     

Seed flavonoids of thePodalyrieae andLiparieae (Fabaceae)

A study of the phenolic compounds of the closely related papilionoid tribes,Podalyrieae andLiparieae, proved that the flavonoid patterns of hydrolysed seed extracts are remarkably conservative. Butin (7, 3, 4-trihydroxyflavanone), 3-hydroxydaidzein (7, 3, 4-trihydroxyisoflavone), vicenin-2 (6, 8-di--D-glucopyranosyl-5, 7, 4-trihydroxyflavone) and orobol (5, 7, 3, 4-tetrahydroxyisoflavone) were isolated and identified as the major flavonoids. The seeds ofAmphithalea, Coelidium, Liparia, Xiphotheca, Calpurnia, Stirtonanthus andPodalyria accumulated three isoflavone O-glycosides that yielded 3-hydroxydaidzein on hydrolysis. In contrast,Virgilia contained a unique combination of vicenin-2 and orobol. Vicenin-2 was also present inCalpurnia as a major compound, butStirtonanthus insignis was the only other species studied that contained orobol (in trace amounts only). Butein, a chalcone, was reported byHarborne from the seed ofCyclopia subternata. This compound's flavanone analog, butin, was the principal component inCyclopia. A cladistic analysis, using flavonoid, alkaloid and morphological data, showed that the seed flavonoids of thePodalyrieae andLiparieae behave rather poorly as cladistic characters. They are, however, of considerable taxonomic value at the tribal level favouring the opinion that the two tribes should be combined. The apparent absence of flavonoids in the seed ofHypocalyptus supports the suggestion that it should be excluded from theLiparieae. Flavonoids also show that theArgyrolobium-group is very different from the tribeCrotalarieae and support the recent transfer of this group to the tribeGenisteae.     

Phylogeny inLabiatae s. l., inferred from cpDNA sequences

Sequences ofrbcL andndhF were analysed independently and in combination to resolve phylogenetic relationships inLabiatae s. l. Monophyly ofLabiatae s. l was supported by all three analyses.Congea tomentosa (Symphoremataceae) is nested withinLabiatae s. l. in therbcL analysis, but emerges as the sister group ofLabiatae s. l. in thendhF and combined analyses. Four noteworthy clades ofLabiate s. l. also are supported by all analyses corresponding to subfamiliesNepetoideae, Lamioideae, Pogostemonoideae andScutellarioideae. Monophyly of subfamiliesChloanthoideae andViticoideae is not supported. A clade comprisingTeucrioideae plusAjuga is supported byndhF and the combined analysis.     

Morphometrics and character state recognition for cladistic analyses in theBletia reflexa complex (Orchidaceae)

Different criteria have been suggested for decisions on character state recognition for morphological characters showing continuous variation from taxon to taxon. A method proposed byMishler andDe Luna seeks to recognize as many character states as the groups of taxon means that are revealed by an analysis of variance (ANOVA) followed by multiple range tests. We apply this method as a guide in decisions of selecting taxonomic characters in species of theBletia reflexa complex. Seven species of the complex, represented by 156 individuals belonging to 54 populations, were the terminal taxa of the study. Character state codes were assigned to 20 characters. These characters together with 12 non-quantitative characters were incorporated into cladistic analyses. Results indicate that the complex is monophyletic only under one outgroup combination.