Showing papers in "Annals of the Missouri Botanical Garden in 1993"

Phylogenetics of seed plants: an analysis of nucleotide sequences from the plastid gene rbcL.

Abstract: We present the results of two exploratory parsimony analyses of DNA sequences from 475 and 499 species of seed plants, respectively, representing all major taxonomic groups. The data are exclusively from the chloroplast gene rbcL, which codes for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO or RuBPCase). We used two different state-transformation assumptions resulting in two sets of cladograms: (i) equal-weighting for the 499-taxon analysis; and (ii) a procedure that differentially weights transversions over transitions within characters and codon positions among characters for the 475-taxon analysis. The degree of congruence between these results and other molecular, as well as morphological, cladistic studies indicates that rbcL sequence variation contains historical evidence appropriate for phylogenetic analysis at this taxonomic level of sampling. Because the topologies presented are necessarily approximate and cannot be evaluated adequately for internal support, these results should be assessed from the perspective of their predictive value and used to direct future studies, both molecular and morphological. In both analyses, the three genera of Gnetales are placed together as the sister group of the flowering plants, and the anomalous aquatic Ceratophyllum (Ceratophyllaceae) is sister to all other flowering plants. Several major lineages identified correspond well with at least some recent taxonomic schemes for angiosperms, particularly those of Dahlgren and Thorne. The basalmost clades within the angiosperms are orders of the apparently polyphyletic subclass Magnoliidae sensu Cronquist. The most conspicuous feature of the topology is that the major division is not monocot versus dicot, but rather one correlated with general pollen type: uniaperturate versus triaperturate. The Dilleniidae and Hamamelidae are the only subclasses that are grossly polyphyletic; an examination of the latter is presented as an example of the use of these broad analyses to focus more restricted studies. A broadly circumscribed Rosidae is paraphyletic to Asteridae and Dilleniidae. Subclass Caryophyllidae is monophyletic and derived from within Rosidae in the 475-taxon analysis but is sister to a group composed of broadly delineated Asteridae and Rosidae in the 499-taxon study.

Patterns of species distributions in the dry seasonal forests of South America

Abstract: Studies of the distributions of species of seasonal woodland habitats in South America by means of dot-mappung and phytosociological analyses indicate the presence of three nodal areas: the Caatingas nucleus of arid northeastern Brazil; the Misiones nucleus, comprising a roughly right-angled triangular area enclosed by lines connecting Corumba-Puerto Suarez (Brazil/Bolivia) southward to Resistencia-Corrientes in northern Argentina, and eastward to the upper Uruguay River valley system in Argentinian Misiones and Brazilian Santa Catarina, and thus including most of eastern Paraguay and the west bank of the Paraguay River; and the Piedmont nucleus, which extends from Santa Cruz de la Sierra in Boliva to Tucuman and the sierras of east Catamarca in northwestern Argentina

A parsimony analysis of the Asteridae sensu lato based on rbcL sequences.

Abstract: A parsimony analysis of 156 representative sequences of the Asteridae sensu lato and 28 outgroup sequences was conducted using a two-tiered approach. First, an analysis of the entire group, including 105 sequences, examined relationships among major lineages within the Asteridae s.l.; subsequently, several clades within the larger group were examined individually in greater detail by including more sequences for the group in question. The search strategy was designed to discover multiple islands of equal parsimony using the heuristic search routine in PAUP. In the broad search and in each more detailed search of subclades, multiple islands were found that imply substantially different relationships

Diversity patterns and biomass of epiphytic bryophytes and lichens along an altitudinal gradient in the northern Andes

Abstract: The difficult accessibility of the canopy of tropical rainforests is probably one of the main reasons why information about the nonvascular tree crown flora is scarce. In this paper full attention is paid to the epiphytic bryophytes and lichens of 59 barks type selected canopy trees, divided over 15 sites along an altitudinal transect ranging from 1,000 to 4,130 m in the Central Cordillera, Colombia. Species-area curves indicated that sampling at each investigated site (altitude) was adequate within the restrictions imposed by the sampling method. Ordination analysis revealed that altitude as a complex ecological factor explained most of the variation in the data. Alpha and beta diversity patterns along the gradient were different for mosses, liverworts, and macrolichens

Phylogenetic relationships among members of Saxifragaceae sensu lato based on rbcL sequence data

Abstract: In an attempt to elucidate relationships among the morphologically diverse members of Saxifragaceae sensu lato, phylogenetic analyses of rbcL sequence data were conducted on representative genera of 16 of the 17 subfamilies. Also included were many putatively related families, as well as a diverse array of dicotyledonous flowering plants. Our phylogenetic analyses suggest that taxa of Saxifragaceae sensu lato are allied with at least 10 separate, often distantly related, lineages of several subclasses of flowering plants. Sequence data, in combination with other lines of evidence, suggest that Saxifragaceae sensu stricto should consist only of subfamily Saxifragoideae, a group of about 30 herbaceous genera that form the core of Saxifragaceae sensu lato

Molecular phylogenetics of the Magnoliidae: cladistic analyses of nucleotide sequences of the plastid gene rbcL.

Abstract: Nucleotide sequences of the plastid protein-coding gene rbcL from 64 species of 36 families in subclass Magnoliidae sensu Cronquist and representatives of all other major seed plant groups were analyzed by parsimony in a series of four analyses. Ceratophyllum (Ceratophyllaceae) was found to be sister to all other angiosperms. Other magnoliids formed five major groups, roughly corresponding to the Magnoliales, Laurales, Aristolochiaceae/Piperales, Nymphaeales, and Ranunculales/Papaverales. Four magnoliid lineages, those with monosulcate or monosulcate-derived pollen (Magnoliales, Laurales, Aristolochiales/Piperales, and Nymphaeales), and the monocots (with the same type of pollen) formed a weakly supported monophyletic group

Phylogenetic hypotheses for the monocotyledons constructed from rbcL sequence data.

Abstract: DNA sequences for the plastid locus that encodes the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL) were determined for 18 species of monocotyledons in 15 families. These data were analyzed together with sequences for 60 other monocot species in a total of 52 families by the maximum likelihood method producing one, presumably optimal, topology. An additional 26 species were added (104 total monocot species) and analyzed by the parsimony method with an outgroup of 18 dicot species producing 109 trees of 3,932 steps. The rbcL data show at least moderate support for seven lineages corresponding to the following orders, superorders, or combinations: Arecanae; Asparagales (excluding Hypoxidaceae) plus Iridaceae; Cyclanthanae plus Pandananae; Dioscoreales; Orchidales; Typhales; and Zingiberanae

Phylogenetic relationships of Cornus L. sensu lato and putative relatives inferred from rbcL sequence data.

Abstract: A parsimony analysis of 46 rbcL sequences was performed to evaluate relationships among Cornus and putative relatives, as well as among subgroups within Cornus. Our results indicate that Alangium, nyssoids (Nyssa, Davidia, and Camptotheca), mastixioids (Diplopanax and Mastixia), Curtisia, and genera of Hydrangeaceae are the closest relatives of Cornus. These taxa, plus Cornus, constitute a «cornaceous clade,» which differs from all previously proposed Cornus alliances. Within this cornaceous clade, four major lineages were identified; (i) Cornus-Alangium, (ii) nyssoids-mastixioids, (iii) Curtisia, and (iv) hydrangeoids. The relationships among the four major lineages within the cornaceous clade remain unresolved

Nucleotide sequences of the rbcL gene indicate monophyly of mustard oil plants.

Abstract: Nucleotide sequences for the chloroplast rbcL gene were obtained from representatives of 11 of the 15 plant families known to produce glucosinolates (mustard oil glucosides). Parsimony analyses indicate that these constitute two widely separated groups and thus imply two independent origins of the mustard oil/myrosin cell syndrome. A strongly supported, major group comprises the mustard family Brassicaceae and its near relatives Capparaceae, Resedaceae, and Tovariaceae along with such morphologically diverse taxa as Bataceae, Bretschneideraceae, Caricaceae, Limnanthaceae, Moringaceae, and Tropaeolaceae. The second mustard oil group is restricted to the euphorbiaceous genus Drypetes

Impact of the eocene on the evolution of Pinus L.

Abstract: Pinus evolved in middle latitudes of the Northern Hemisphere in the middle Mesozoic By the late Cretaceous pines had spread east and west throughout Laurasia, attaining high diversity in eastern Asia, the eastern United States, and western Europe, but having little representation at high northern latitudes Changing climates in the early Tertiary established warm and humid tropical/subtropical conditions in a broad zone to 70°N throughout middle latitudes Pines and their relatives disappeared from many middle-latitude areas during this time and were replaced by diverse angiosperm taxa of the boreotropical flora, which were adapted to the equable, tropical climate The effect of this climate change and spread of boreotropical flora was to displace pines from their former habitats A hypothesis is defended that pines shifted, during the three warm periods of the Eocene, into three major refugial areas in the Northern Hemisphere: high latitudes, low latitudes, and upland regions of middle latitudes, especially in western North America Some of these refugial areas (eg, Mexico/Central America) underwent active volcanism and mountainbuilding in the Eocene and became secondary centers of pine diversity Many phylogenetic patterns within Pinus can be traced to this fragmentation, isolation, and evolution in Eocene refugia Subsections Oocarpae and Sabinianae appear to have originated from refugia in Mexico and Central America Older subsections such as Sylvestres, Ponderosae, Contortae, and Strobi were distributed over several refugia; subsections Leiophyllae, Australes, and Cernbroides evolved in southern refugia in North America; and Canarienses evolved in southern refugia along the Tethys seaway in Eurasia Following the cooling and drying of the climate at the end of the Eocene, many angiosperm taxa of the boreotropical flora became extinct and pines recolonized middle latitudes, a zone they have occupied to the present Migration out of refugia provided additional opportunities for hybridization and introgression, as formerly isolated lineages expanded and met

Phylogenetic relationships of the Geraniaceae and Geraniales from rbcL sequence comparisons.

Abstract: Parsimony analyses of DNA sequence data from the chloroplast rbcL gene were used to assess the circumscription and phylogenetic position of the Geraniaceae, generic relationships within the family, and the affinities of the families previously assigned to the order Geraniales. The other families placed in the Geraniales in recent higher-order classifications fall into four well separated lineages, none of which appears to be closely related to the Geraniaceae. Only Hypseocharis, often included in the Oxalidaceae, receives strong support as a close relative to the monophyletic Geraniaceae sens. str., as suggested by Boesewinkel on the basis of seed anatomy

Tribal relationships in Onagraceae: implications from rbcL sequence data.

Abstract: The evolutionary relationships among the seven tribes of Onagraceae, the most intensively studied family of intermediate size, have been examined from morphological and molecular perspectives. Previous cladistic analyses of chloroplast (cp) and nuclear ribosomal (nr) DNA restriction sites, nuclear-encoded rbcS amino acid sequences, nrRNA nucleotide sequences, and morphological characters, produced trees that agree in defining the tribe Jussiaeeae as the sister group to the rest of the family. However, the relationships among the rest of the tribes are not completely resolved by these analyses. Cladistic analyses of sequence data from the chloroplast encoded rbcL gene produced results that bear on two malor issues: (i) intertribal relationships within Onagraceae, and (ii) congruence with other cladistic analyses

Systematics of the Ericaceae, Empetraceae, Epacridaceae and related taxa based upon rbcL sequence data.

Abstract: The Ericaceae, Epacridaceae, and Empetraceae are usually recognized as closely related families of woody plants that share a preference for acidic soils, anthers that invert in development, and the presence of endosperm haustoria, among other characteristics. The Empetraceae are recognized as distinctive because of their often unisexual and wind-pollinated flowers. Epacridaceae are distinguished from Ericaceae by anthers that open by slits rather than pores and a primarily Australian distribution. Phylogenetic relationships of these related families are investigated using nucleotide sequences of the plastid gene rbcL. Parsimony analyses indicate a monophyletic, broadly defined Ericaceae that includes Empetraceae and Epacridaceae

Character-state weighting for cladistic analysis of protein-coding DNA sequences

Abstract: Nucleotide data are a restricted character system complex enough to confound phylogenetic analyses yet simple enough to permit establishment of probability models for sequence change and corresponding character-state weighting schemes. We have previously developed a general method for weighting DNA data that is here elaborated for protein-coding sequences. Included in the present model are corrections for (i) multiple substitution events, (ii) transition/transversion bias, and (iii) differential proportions of changes occurring at first, second, and third codon positions. This model is shown to be generally consistent for all phylogenetically useful data

Systematics of Ruellia (Acanthaceae) in southern South America

Abstract: Ruellia comprises 23 species in southern South America, which display great diversification in flower and inflorescence morphology, presumably associated with a wide array of pollinators; this has resulted in the evolution of many different floral syndromes. It is suggested that this diversification could have evolved through heterochronic developmental changes associated with cleistogamy that produce morphological variation in flower form, selected by different types of pollinators. The generic limits of Ruellia are discussed in relation to this variation, and several generic names are considered synonyms, including Penstemonacanthus. Seven informal taxonomic groups of species are delimited: Chiloblechum, Dipteracanthus, Ebracteolati, Hygrophiloidei, Physiruellia, Ruellia, and Salpingacanthus

Interfamilial relationships of the Asteraceae: insights from rbcL sequence variation.

Abstract: Nucleotide sequences of the chloroplast gene rbcL were analyzed to examine relationships among the large, distinctive family Asteraceae and eight putatively closely related families. Phylogenetic analysis of a total of 24 sequences of rbcL identified a lineage consisting of two families, the Goodeniaceae and Calyceraceae, as the sister group to the Asteraceae. In addition, a strongly supported major monophyletic clade consisting of Asteraceae, Goodeniaceae, Calyceraceae, Corokia (Cornaceae sensu Cronquist), Menyanthaceae, Lobeliaceae, and Campanulaceae was found. These results clearly distance from the Asteraceae certain groups previously considered closely related; moreover, the results support alternative hypotheses of affinity that were based upon floral and inflorescence morphology, biogeography, pollen morphology, chemistry, and pollen-presentation mechanisms

Phylogenetic analysis of the Zingiberales based on rbcL sequences.

Abstract: Morphological data have been used previously to construct phylogenies of the eight families of the Zingiberales, one of the most widely accepted monophyletic groups of flowering plants. To provide additional support for phylogenetic relationships within the order, and placement of the order among monocots, we present a parsimony analysis of DNA sequences from the chloroplast-encoded gene, rbcL, for 2 1 species of Zingiberales and proposed relatives. Five analyses with equal, and differential weights were performed. All analyses resulted in the same most parsimonious tree for taxa within the Zingiberales and the immediate outgroup. The closest sister group to the Zingiberales based on these data is a clade containing Commelinaceae/Haemodoraceae/Pontederiaceae

An analysis of relationships within the Cupressaceae sensu stricto based on rbcL sequences.

Abstract: The analysis of rbcL sequences of representative species of 13 of the 20 genera of the Cupressaceae sens. str. has produced a cladogram that agrees with data derived from other sources. The monophyly of the family is well supported. The cladogram provides support for the recognition of a basically northern subfamily (Cupressoideae) and a southern subfamily (Callitroideae), but the boundary between the subfamilies needs to be realigned by moving Tetraclinis from the Callitroideae to the Cupressoideae. The tribal arrangement of Li is largely artificial: the Libocedreae, Cupresseae, and Thujopsideae are clearly paraphyletic

Revision del genero Styphnolobium (Leguminosae: Papilionoideae: Sophoreae)

Abstract: The genus Styphnolobium is recognized as a segregate from Sophora on the basis of habit, stipels, bracteoles, legume, and chromosome number. It is enlarged from four to nine species through the description of five species new to science: Styphnolobium burseroides, S. monteviridis, S. parviflorum, S. protantherum, and S. sporadicum. Two sections are recognized, one requiring the new combination section Oresbios. The genus is centered in the Mexican-Mesoamerican area. Through similarities in habit, bracteoles, and dehiscence of the legume, it is clearly most closely related to Calia

Monograph of the neotropical species of Asplenium sect. Hymenasplenium (Aspleniaceae).

Abstract: Asplenium sect. Hymenasplenium is one of the best defined groups of Asplenium, being characterized by creeping rhizomes, dorsiventrally symmetrical steles, swollen petiole bases, unique rachis-costae structure, and chromosome base numbers of x = 38 or 39. In the Neotropics, the section has ten species and three hybrids. The species are A. delitescens, A. hoffmannii, A. laetum, A. obtusifolium, A. ortegae, A. purpurascens, A. repandulum, A. riparium, A. triquetrum, and A. volubile. The hybrids are A. × papyraceum (of unknown parentage), A. delitescens × A. laetum, and A. xincisoserratum (= A. hoffmanni × A. laetum). All the aforementioned species and hybrids are endemic to the Neotropics. Central America and the Andes harbor the most species and endemics. A cladistic analysis was not done because the neotropical species of the section apparently do not form a monophyletic group separate from the paleotropical ones

The misconstrued and rare species of Commelina (Commelinaceae) in the eastern United States

Abstract: Five species of Commelina (Commelinaceae), all introduced in the eastern United States, are reviewed and discussed. The widespread but overlooked C. caroliniana is contrasted with the more common C. diffusa, and the species are found to be distinguished best by their seeds. Commelina gigas is determined to be a polyploid of C. diffusa, and the new combination C. diffusa var. gigas is made. Variety gigas is considered likely to have been separately introduced. Commelina benghalensis probably became naturalized in Florida early this century. Of the two recently discovered species, C. forskaolii is known from a single Florida population that may have been eradicated, and C. nigritana var. gambiae is becoming well established along roadsides in Florida

Revised circumscriptions and subgeneric taxonomies of Calandrinia and Montiopsis (Portulacaceae) with notes on phylogeny of the portulacaceous alliance.

Abstract: Cladistic analysis of Portulacaceae supports a revised taxonomy of Calandrinia sensu lato. Calandrinia, as here circumscribed, comprises ca. 14 western American species in three sections: Calandrinia, Acaules, and Monocosmia. Previous taxonomies classified over 100 species in Calandrinia but recognized Monocosmia as a distinct genus. Calandrinia sects. Calandrinia and Monocosmia are probably cladistically nested in section Acaules and are not sister groups of either Rumicastrum or Montia, as proposed in a previous cladistic analysis. Montiopsis Kuntze, traditionally included in Calandrinia, comprises ca. 15 western South American species in two subgenera, Montiopsis and Dianthoideae (...)

Phylogenetic relationships of the Bromeliiflorae-Commeliniflorae-Zingiberiflorae complex of monocots based on rbcL sequence comparisons

Abstract: Four cladistic hypotheses were constructed for Dahlgren's Bromeliiflorae-Commeliniflorae-Zingiberiflorae complex, primarily from suggestions of affinities according to morphology-based treatments: (i) Dahlgren's treatment of the families is correct; (ii) the bromeliaceae and Zingiberales are sister groups; (iii) the complex is monophyletic, with the Arecaceae as the closest outgroup; and (iv) a clade that contains the Bromeliaceae and Commelinaceae is monophyletic. These four hypotheses were evaluated using sequence data from the chloroplast gene, rbcL, that codes for the large subunit of ribulose-1,5-biphosphate carboxylase/oxygenase. Results were compared between a broad analysis of 499 rbcL sequences and a smaller data set that included only families of the complex plus the Arecaceae (52 taxa)

Pollen development and fertilization in lacandonia-schismatica (lacandoniaceae)

Abstract: The flower of Lacandonia schismatica is bisexual. Three or sometimes four bilocular or trilocular anthers occupy the center of the flower inside the zone of carpels. The anther wall comprises four layers: epidermis; endothecium whose cells develop helical wall thickenings; one middle layer, which disappears early; a tapetum of the secretory type. The tapetal cells apparently form cytoplasmic bridges among themselves. The microspore tetrads are in an isobilateral arrangement, surrounded by a thick wall. The mature anther wall has only two cell layers: epidermis and endothecium. The pollen grain is three-celled by the time germination occurs. Anther dehiscence has not been observed and probably does not occur. Pollination of Lacandonia schismatica occurs in the unopened flower bud

A Revision of the Genus Pleurothyrium (Lauraceae)

Abstract: Pleurothyrium, a genus of Lauraceae mostly consisting of trees, ranges from Guatemala to Bolivia and possibly Southern Brazil. The genus is best represented in Peru, Ecuador, and Colombia and mostly occurs at low elevations. In this revision 39 species are included in Pleurothyrium, of which 19 are described as new. Taxonomic history, characters, and phylogenetic classification are discussed. Data on phenology, habitat preference, and altitudinal range are presented when available

The genus Clerodendrum (Verbenaceae) in Mesoamerica.

Abstract: Clerodendrum is the largest genus of Verbenaceae, with about 560 species and varieties It is most abundant in Africa and Asia, with only 20 species native to the New World In Mesoamerica, 1 5 species and one variety are known: five of these species are native, and the remainder are cultivated as ornamental plants; several are more or less naturalized Three of the introduced species and one of the native ones are first records for the Mesoamerican region

El genero Inga (Leguminosae: Mimosoideae) del sur de Mexico y Centroamerica, estudio previo para la Flora Mesoamericana

Abstract: As a precursor to the treatment of Inga for the Flora Mesoamericana, this summary of the genus is presented, including the nomenclature, taxonomy, and variation of all the species, as well as the possible influence of humans in altering patterns of distribution and variation. Seven names are lectotypified: Inga alba, I. densiflora, I. multijuga, I. oerstediana, I. paterno, I. ruiziana, and I. vera. Representative specimens are cited for all species, including areas outside of Mesoamerica. Thirteen species are described as new: Inga bella, I. cabrerae, I. calcicola, I. cuspidata, I. chiapensis, I. dasycarpa, I. davidsei, I. dwyeri, I. ismaelis, I. lacustris, I pseudoinvolucrata, I. sinacae, and I. tenella

Plant life-forms and biogeographic relations of the flora of Lagunillas (30 degrees S) in the fog-free Pacific coastal desert.

Abstract: The coastal desert of north-central Chile supports a rich but poorly known flora. Here, we document the importance of the annual and perennial habits in the flora of Lagunillas (30°S), at the southern transition from the desert to the mediterranean climate region, and discuss the origin of the desert flora by examining the geographic distribution of the taxa at the level of genus. The distribution was used to assign the species to six biogeographic elements. Annual plants represent 41% of the total flora (191 species) and are the most important life form. Excluding non-native weeds, however, decreases the importance of annuals to 33%. This value is higher than that for high-altitude deserts, but lower than for most other, less-equitable, lowland deserts both in North America and eastern Asia (...)

A revision of Panicum subg. Dichanthelium sect. Dichanthelium (Poaceae: Panicoideae: Paniceae) in Mesoamerica, the West Indies, and South America

Abstract: A revision of Panicum subg. Dichanthelium sect. Dichanthelium (Poaceae: l'anicoideae: Paniceae) for Mesoamerica, the West Indies, and South America is presented, considering exomorphological, anatomical data and caryological characters. Thirty-seven species and seven varieties of section Dichanthelium of Panicum are recognized from this area. Panicum caparaoense is described as a new species, and Panicum dichotomum var. tenue as a new combination. An anatomical description of section Dichanthelium, with photomicrographs of representative species, is given, together with a key, morphological descriptions, and distribution maps. It is concluded that section Dichanthelium is not sufficiently distinct to be regarded as a separate genus. The taxonomic position of Dichanthelium within Panicum is discussed