Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact email@example.com with any questions.
Seven species of Porella are present in Australasia and the south Pacific: P. acutifolia (Lehm. & Lindenb.) Trevis. var. acutifolia, P. acutifolia var. linguifolia (Steph.) M. L. So, comb. nov., P. cranfordii Steph., P. elegantula (Mont.) E. A. Hodgs., P. geheebii (Steph.) Grolle, P. grollei S. Hatt., P. maxima (Steph.) M. L. So, comb. nov., and P. viridissima (Mitt.) Grolle. Porella pulcherrima Herzog & S. Hatt. is placed under the synonymy of P. elegantula, and P. queenslandica (Steph.) S. Hatt. under P. cranfordii. Porella hirtella (Steph.) S. Hatt. and P. novoguinensis S. Hatt. are treated as synonymous with P. maxima. Porella javanica (Steph.) S. Hatt. is excluded from the region. Lectotypes are designated for Madotheca latifolia Colenso and M. amoena (Colenso) Martin. A key to all the species in the region is provided.
A new species of Ribes is described from Ecuador as a result of the ongoing treatment of Grossulariaceae for the Flora of Ecuador. Ribesnanophyllum resembles Ribes hirtum and Ribes erectum, but differs from the first by its obovate leaves and cup-shaped flowers, and from the second by its stems and ovaries bearing long-stipitate glands. The eight Ecuadorian species belong to the Neotropical subgenus Parrilla. Ribes in Ecuador produces flowers and fruits throughout the year, is distributed in montane forests, subpáramos, and páramos between 2,750 and 4,267 meters above sea level, and occurs mainly in the northern part of the country.
One area of risk assessment for transgenic crops concerns cross-compatible wild and weedy relatives. In squash (Cucurbita pepo), free-living populations are diverse in their distributions, ecologies, histories, and genetic and phenotypic compositions. As part of the effort to understand this diversity, random amplified polymorphic DNA (RAPD) data were collected from 37 wild or weedy populations and 16 cultivars, which together represented all infraspecific taxa of C. pepo. Twenty-six primers yielded 70 scorable and variable markers. The presence/absence of bands for these markers produced a data matrix which was analyzed using cluster analysis. The analysis confirmed the relationships among infraspecific taxa that had been revealed, in part, in previous genetic analyses (e.g., isozymes, chloroplast DNA restriction-site mutations, inter simple sequence repeats). Also supported were findings of varying degrees of gene flow from cultivars into free-living populations. Some of the RAPD variation in subsp. ovifera var. ozarkana populations was found to be correlated with the distribution of the drainage systems along which these populations are dispersed. Finally, the RAPD results support the idea that transgenic gene flow experiments with free-living populations should consider using representatives from each of the three free-living taxa, as well as from genetically or ecologically distinct populations within these taxa.
Leaflet anatomy of 30 species in the genera Alantsilodendron, Calliandropsis, Dichrostachys, and Gagnebina, was studied using hand-sections, leaf clearings, and scanning electron microscopy. Variation was found in the distribution of stomata, venation patterns, and especially sclerification associated with the vascular tissue. Terminal idioblasts are common and diverse, with enlarged tracheids, tracheoidal elements, reticulate and pitted tracheids, and sclereids associated with the terminal veinlets. In addition, sclerification of bundle sheath cells was found in two of the genera, and non-terminal sclereids of unknown origin are reported in yet a third genus. Although many characters of leaf anatomy are strongly correlated with ecological factors, an evaluation of such characters in the context of a preliminary phylogeny indicates that they are useful in phylogeny reconstruction. The major limitation in the use of anatomical characters of leaves in phylogenetics seems to be the difficulty in defining discrete character states and not ecological plasticity.
We here report the results from two parsimony analyses of all 15 recognized taxa in Hippophae (Elaeagnaceae), one based on chloroplast DNA (cpDNA), and one based on a combined data set of morphological characters and cpDNA. The genera Elaeagnus and Shepherdia were used as outgroup taxa. In general, the results are congruent with a previous RAPD study, and partly with some of the previous proposed classifications. Monophyly of Hippophae is strongly supported. The most widespread species, H. rhamnoides, is, in spite of low support, most likely monophyletic and distinguished by a single molecular synapomorphy. Due to weak internal support, we refrain from recognizing any sections within the genus. Three taxa, first published as nomina nuda but used by several authors, are here validated and/or described. These are Hippophaeneurocarpa subsp. stellatopilosa, H. goniocarpa, and H. litangensis. The latter two were originally suggested to form one species with two subspecies, but they are clearly not monophyletic, a single lineage of evolution, but rather are sister to two different species in the analyses. Together with earlier information from isozymes (unpubl. data) and RAPDs, we believe they are results of two independent hybridisations and we describe them as species. In conjunction, a maternal mode of cpDNA inheritance is suggested.
The Old World dry tropical family Moringaceae is remarkable for the great diversity of habit and floral morphology found within its only genus, Moringa. To infer the phylogenetic relationships of all 13 species, parsimony analyses of morphological data and DNA sequences from a low-copy nuclear region (PEPC), a chloroplast region (trnG), and a tandemly-repeated nuclear region present in high copy number (ITS) were conducted of each data set separately and combined. Characters from studies of ontogeny substantially enhanced the resolution of the morphological data set. The Incongruence Length Difference test indicated the congruence of all data sets, as did Templeton tests comparing the single tree resulting from the combined analysis in the context of the individual data sets. This tree is presented as the preferred topology, in which the four bottle trees appear in a basal paraphyletic assemblage, with the three species of slender trees (including the economically important M. oleifera) forming a clade that is sister to a clade of the six species of tuberous shrubs and trees of northeast Africa. Moringa is currently divided into three sections, but because of the basal grade, it cannot be divided into useful monophyletic infrageneric taxa. The phylogeny-based informal terms “bottle tree grade”, “slender tree clade”, and “tuberous clade” are suggested as alternatives. Relationships within Moringa were found to be largely congruent with a previous study of wood anatomy.
A molecular phylogenetic study based on chloroplast DNA restriction site and ITS sequence data shows that the two Macaronesian endemics, Lavatera phoenicea and Lavatera acerifolia, represent two independent introductions into the Canary Islands. The molecular phylogenies, combined with morphological, ecological, and biogeographical data, indicate that Lavatera phoenicea may be a bird-pollinated relict of an ancient laurel forest. Lavatera acerifolia, however, is nested in a derived clade of the Lavatera-Malva taxa from the Mediterranean region, suggesting a more recent introduction into the Canary Islands. Incongruence between chloroplast and nuclear phylogenies suggests that hybridization may have played a role in the evolution of L. acerifolia. Several features of L. phoenicea, such as corolla color and high nectar production, appear to be plesiomorphic and are still present because of historical constraints. In contrast, woodiness is a derived feature that originated as an adaptation to insular conditions.
Chloroplast (rbcL, trnL intron, trnL-trnF spacer) and nuclear ribosomal (ITS1, 5.8S, ITS2) DNA sequences were analyzed to identify the closest terrestrial relatives of the mangrove family Avicenniaceae. These plants have been classified within or near Verbenaceae in most synoptic treatments of angiosperms. Surprisingly, Avicenniaceae were placed as part of Acanthaceae s.l. in analyses of all data sets, using both parsimony and maximum likelihood. Within Acanthaceae s.l., our analyses consistently placed Avicennia as sister to Thunbergioideae but without strong support. Constrained maximum likelihood analyses indicated that alternative placements of Avicennia near the base of Acanthaceae s.l. were not significantly less likely than the sister group relationship with Thunbergioideae. However, placement with Verbenaceae was significantly less likely, as was placement with Pedaliaceae. Morphological evidence is reviewed in this phylogenetic context, and we suggest that articulated nodes and inflorescence structure (including flowers subtended by a bract and two bracteoles) may provide synapomorphies for Avicennia and Acanthaceae s.l. We can identify no clear morphological synapomorphies linking Avicennia to Verbenaceae. Avicennia shares a number of features with each of its putative relatives that are likely to be symplesiomorphic or are of uncertain phylogenetic status.
Gaylussacia includes 49 species of understory shrubs in the heath family (Ericaceae) with a disjunct distribution in North and South America. Little is known about evolutionary relationships among the species. To investigate phylogenetic and biogeographic relationships in Gaylussacia, three data sets were constructed and analyzed cladistically using parsimony: morphology, nuclear ribosomal internal transcribed spacer DNA sequences, and chloroplast trnL intron-trnF spacer DNA sequences. Molecular data sets were analyzed in two ways to determine the phylogenetic informativeness of insertion/deletion events. Comparison of results from separate analyses of each data set showed some incongruencies between the nuclear and chloroplast data sets, indicating possible past hybridization or lineage sorting. Combined analyses were conducted for ITS and morphology, and for trnL-trnF and morphology. The monophyly of the genus including G. brachycera was not strongly supported. In addition, the traditional sectional divisions of Gaylussacia were not supported in the morphological and nuclear DNA analyses. Finally, a broader perspective on the disjunct distribution of Gaylussacia includes the possibility of a North American origin for the genus, rather than a South American origin as previously hypothesized.
Macromeria viridiflora (Boraginaceae), a perennial that occurs in isolated populations on the “Sky Islands” of southwestern North America, displays geographic variation in floral morphology. This study examines an array of morphological traits and describes geographic patterns of variation throughout the range of the species. Univariate and multivariate analysis of morphometric data from eight sites across the range of the species shows significant among-population variation in 19 out of 20 vegetative and floral traits measured. Flower size variation is particularly strong and follows a latitudinal cline, with flowers being much larger in the southern part of the range and smaller in the northern part of the range. Observations also indicate differences in floral visitors between northern and southern populations. While flowers in all populations were visited by hummingbirds, the large-bodied hummingbirds visiting plants in the southern regions are not present in the northern regions, where flowers are visited by hummingbirds with nearly half the body size and much shorter bills. This difference in body size of pollinators mirrors the geographic variation in flower size in M. viridiflora, suggesting that pollinator-mediated selection may be acting upon the species.
The phylogenetic relationships of the 16 species of Monarda (Lamiaceae) were investigated using sequences of the internal transcribed spacer regions of nuclear ribosomal DNA. Thymus and Mentha were used as outgroups, and Blephilia, Clinopodium, Conradina, Hesperozygis, Monardella, Pycnanthemum, and Ziziphora were included in the ingroup to test the monophyly of Monarda. Two parsimony searches were performed after removing redundant sequences from the analysis: one with indels scored as missing and a second with indels treated as binary characters. Both searches yielded congruent results, but the treatment of indels as binary characters resulted in considerably more resolution within Monarda. There was strong support for the monophyly of Monarda and a close relationship was found between Monarda, Blephilia, and Pycnanthemum. The molecular phylogeny was completely congruent with the infrageneric classification of the genus. Our results were consistent with hypotheses of hybridization between M. fistulosa and M. lindheimeri in Texas. Despite considerable morphological variation among many species, especially in floral characters, little molecular diversification was found in those same species groups. Intraspecific polymorphism in ITS sequence was found in over half the species examined, and may be attributable to ancestral polymorphism, hybridization, or detection of paralogous loci.
A phylogenetic study was conducted on current members (Chelone, Chionophila, Keckiella, Nothochelone, Pennellianthus, Penstemon, and Tetranema) and former members (Collinsia, Freylinia, Halleria, Russelia, Scrophularia, Tonella) of tribe Cheloneae to test for monophyly, examine biogeographic patterns, and assess relationships of Cheloneae to genera previously excluded from the tribe. Nucleotide sequence data from ITS and matK used in separate and combined analyses yielded congruent trees. Our results provide evidence that Collinsia and Tonella should be transferred from Collinsieae to Cheloneae and that Russelieae should be expanded to include Tetranema. Our results also indicate a New World origin for Cheloneae with dispersal of the Asian component over Beringia. North American Cheloneae may have originated in the Klamath Region of the western United States with expansion to the Rocky Mountain/Columbia Plateau region followed by diversification of several genera. We propose a post-Tertiary evolutionary radiation of the large North American genus Penstemon.
Marcgraviaceae is a distinctive neotropical family with approximately 130 species distributed from the Caribbean and southern Mexico to northern Bolivia. Phylogenetic analysis of rbcL sequence data strongly supports the monophyly of the family. NdhF, trnL-F, and rbcL sequence comparisons resolve two major lineages within Marcgraviaceae corresponding to subfamilies Marcgravioideae and Noranteoideae. The monogeneric Marcgravioideae is united by both morphological synapomorphies and molecular data. In contrast, subfamily Noranteoideae appears to be delimited by plesiomorphic morphological characters but is supported as monophyletic by molecular data. Our data suggest a close relationship between representative species of Schwartzia and Ruyschia, which share a unique 47 base pair insertion in the trnL-F spacer but have not been allied in morphological classifications. Despite considerable morphological differences among taxa of Noranteoideae, our sequence data do not resolve some currently recognized genera as monophyletic groups.
Results of phylogenetic analyses of nuclear 18S–26S rDNA internal transcribed spacer (ITS) region sequences for representatives of most genera of helenioid Heliantheae and various members of Heliantheae s.s. (sensu stricto) and Eupatorieae help to clarify major lineages and relationships in the clade corresponding to Heliantheae s.l. (sensu lato) and Eupatorieae. Most subtribes of helenioid Heliantheae as circumscribed by Robinson (1981) correspond closely with ITS clades. Polygeneric subtribes of helenioid Heliantheae that appear to be monophyletic based on ITS data include Flaveriinae sensu Turner and Powell (1977), Madiinae sensu Carlquist (1959), and Peritylinae sensu Robinson (1981). Chaenactidinae sensu Robinson (1981) is polyphyletic, but most members of the group are encompassed within only four ITS clades. Based on the ITS data and results of combined analyses of ITS variation plus previously published morphological and chloroplast DNA data, we conclude that Heliantheae s.s. and Eupatorieae represent nested clades within helenioid Heliantheae, as previously suggested. Loss of paleae appears to have been a rare occurrence during radiation of Heliantheae s.s.; only one epaleate taxon that we sampled (Trichocoryne) was placed within an ITS clade of otherwise paleate taxa, referable to Heliantheae s.s. We conclude that expression of paleae in Heliantheae s.s., Madiinae, and Marshallia is homoplasious. We also conclude that pappi of bristles or bristle-like subulate scales have arisen in various lineages of Heliantheae s.l. and in general have received too much weight in previous circumscriptions of suprageneric taxa. Multiple examples of extreme dysploidy from high (putatively polyploid) ancestral chromosome numbers in helenioid Heliantheae are evident from the phylogenetic data. Bidirectional ecological shifts between annual and perennial habits and repeated origins of woodiness from herbaceous ancestors also can be concluded for helenioid Heliantheae. Based on modern distributions of taxa and evident phylogenetic patterns, Baeriinae, Madiinae, and the x = 19 “arnicoid” taxa probably share a common Californian ancestry. To produce a tribal taxonomy for Heliantheae s.l. that better reflects phylogenetic relationships, Eupatorieae and (provisionally) Heliantheae s.s. are retained in essentially the traditional senses, Helenieae is recognized in a restricted sense, Madieae and Tageteae are expanded, and three new tribes (Bahieae, Chaenactideae, and Perityleae) are erected. In Madieae, three new subtribes (Arnicinae, Hulseinae, and Venegasiinae) are recognized, in addition to Baeriinae and Madiinae. In Peritylinae, a new combination, Perityle montana, is proposed for Correllia montana.