A new rheophytic liverwort species, Lejeunea topoensis (Lejeuneaceae), is described from the Andes of Ecuador and southern Brazil. The new species is intermediate between Lejeunea and Neopotamolejeunea, combining short leaf insertions typical of the former genus, and robust stems and pinnate branching with numerous short sexual branches characteristic of the latter. Neopotamolejeunea is therefore reduced to subgeneric status under Lejeunea. The discovery of L. topoensis adds a further species to the growing list of taxa with disjunct distribution in the Andes and the Atlantic coastal region of Brazil. It is postulated that the disjunct range resulted from long-distance dispersal, although it might to some extent reflect under-representation of collections. The new name L. juruana, replacing Neopotamolejeunea uleana, is proposed. Cheilolejeunea rupestris is a new synonym of C. beyrichii.

To clarify long-standing disagreements about the taxonomic and phylogenetic status of Sphagnum macrophyllum and S. cribrosum, twenty-five samples of S. macrophyllum and twenty-four of S. cribrosum, including the rare wave-form morphotype, were sampled from ten states of the eastern United States. The data set included intensive sampling from three populations in North Carolina. Three anonymous genomic regions (rapdA, rapdB and rapdF) were sequenced for all the samples; two (nuclear) LEAFY introns (LEAFY1 and LEAFY2) and one chloroplast locus (trnG) were sequenced for all the samples excluding the twenty-two within-population North Carolina samples. The results showed that S. macrophyllum and S. cribrosum are reciprocally monophyletic with maximum parsimony bootstrap support and significant Bayesian posterior probabilities. Genetic analyses based on neutral coalescence models suggest that the simplest allopatric speciation model—the isolation model with no subsequent gene flow and constant population sizes—cannot be rejected. Nevertheless, some topological conflicts among loci suggest the possibility of limited interspecific hybridization. This study also showed that the morphologically distinctive wave-form is nested within S. cribrosum and wave-form samples from Singletary Lake make up a clade of nearly identical plants. Interestingly, S. macrophyllum and S. cribrosum are morphologically highly similar but are reciprocally monophyletic and highly differentiated, whereas the unique and morphologically divergent wave-form is genealogically derived from within normal S. cribrosum.

Cheilanthoid ferns have a worldwide distribution and are found in rocky and seasonally dry habitats. Difficulty in deciphering natural lineages of cheilanthoids has been attributed to morphological convergence associated with adaptation to xeric environments. The goal of this study was to investigate the monophyly of the genus Pellaea by generating a DNA sequence-based cheilanthoid phylogeny. DNA sequences of the chloroplast rps4 gene and rps4-trnS intergenic spacer (IGS) were generated from 105 exemplars; chloroplast trnL-F IGS sequences were also generated from 60 of these samples. Results show that Pellaea sensu Tryon and Tryon is polyphyletic; Pellaea sections Holcochlaena and Ormopteris are distant relatives of sections Pellaea and Platyloma and have closer relationships with Doryopteris. A monophyletic circumscription of “pellaeoid” ferns is here defined to include traditional P. sect. Pellaea, P. sect. Platyloma, Astrolepis, and elements of Paragymnopteris and Paraceterach, all of which form a clade sister to Argyrochosma. Several other novel systematic implications of cheilanthoid relationships are also presented. The distribution of base chromosome numbers across the cheilanthoid phylogeny reveals potential synapomorphies of x  =  29 for the pellaeoid clade and x  =  27 for Argyrochosma, and suggests a trend toward reduction in base number during cheilanthoid evolution. Current geographic distribution of cheilanthoid ferns suggests a history of multiple introductions into the Old World from several ancestral New World lineages.

Peach palm (Bactris gasipaes Kunth.) is the only Neotropical palm domesticated since pre-Columbian times. It plays an important role not only at the local level due to its very nutritious fruits, but also in the international market for its gourmet palm heart. Phylogenetic relationships of the peach palm with wild Bactris taxa are still in doubt, and have never been addressed using molecular sequence data. We generated a chloroplast DNA phylogeny using intergenic spacers from a sampling of cultivars of Bactris gasipaes as well as putative wild relatives and other members of the genus Bactris. We estimated phylogenetic relationships using maximum parsimony (MP), maximum likelihood (ML), and Bayesian analysis. Our results indicated a close affinity between three taxa: Bactris gasipaes var. gasipaes, B. gasipaes var. chichagui, and B. riparia. There was no clear differentiation between these three taxa at the level of chloroplast sequences, and they shared a unique inversion that we characterized in this paper. Bactris setulosa, a species potentially related to the Bactris gasipaes complex, appeared highly divergent, and seemed to be a composite taxon with affinities outside the complex. We also investigated nuclear microsatellite polymorphisms at 8 loci within Bactris gasipaes, B. riparia, and B. setulosa, finding a pattern of relationships in agreement with the cpDNA data. The results presented here are important for future studies on domestication and crop improvement of Bactris gasipaes.

Molecular phylogenetic analyses using the chloroplast marker ndhF and a single copy nuclear marker, knotted1, show that the panicoid grasses bearing sterile branches (bristles) in their inflorescences form a monophyletic group. The genus Cenchrus is monophyletic, and monophyly of Pennisetum cannot be ruled out. Setaria is not monophyletic, either as a whole, excluding the palm-leaved species from section Ptychophyllum, or excluding various uncertainly placed species such as S. grisebachii. There is also no evidence that Setaria and Paspalidium form a monophyletic group. The Australian genera Zygochloa, Spinifex, and Pseudoraphis are placed in the ‘bristle clade’, confirming that inflorescences of these grasses are homologous with the inflorescences composed of spikelets and sterile branchlets (bristles). Comparison of the nuclear and chloroplast gene trees identifies several taxa as tetra- or higher polyploids; these are confirmed by southern hybridization. In particular, the Australian species of Paspalidium are allopolyploid, a novel and unexpected result. Zuloagaea bulbosa, a species that lacks the synapomorphic bristles in its inflorescence, is confirmed as a morphologically anomalous member of the clade, and is clearly allopolyploid. This study demonstrates the utility of knotted1 as a phylogenetic marker; we show that it is single copy in diploid taxa and that it exhibits adequate variation to distinguish closely related species. Interestingly, inflorescence morphology correlates only partially with relationships suggested by either nuclear or chloroplast trees, suggesting that inflorescence form is easily changed over evolutionary time.

The tribe Stipeae occurs in temperate and warm temperate grasslands of Eurasia, Australia, and America. Although generic circumscription within the tribe has recently undergone significant changes, the American genus Piptochaetium has been clearly defined by morphological and anatomical characters. It includes 36 species and 2 varieties, most of them widely distributed in temperate grasslands of South America. Phylogenetic analyses were conducted in Piptochaetium and allied genera of the Stipeae, in order to test the monophyly of the genus, re-examine infrageneric taxa, and analyze relationships among species of this genus and allied genera of Stipeae. Two chloroplast molecular markers, trnL-F and rpl16, as well as morphology were used. Topology between morphological and molecular data mainly differs in the relationships of Piptochaetium with Anatherostipa and Piptatherum. Molecular and combined analyses yielded two major clades in the tribe: the x  =  11 Clade with Piptochaetium, Aciachne, Anatherostipa, and Jarava vaginata, and the Aneuploid Clade with Jarava, Nassella, and Piptatherum. Monophyly of Piptochaetium was confirmed by morphological and total evidence (morphology and DNA data) analyses. Monophyly of sect. Podopogon, sect. Piptochaetium and Nassella were only supported by the total evidence analysis. Circumscription of Jarava is also discussed.

Misodendrum comprises eight species of aerial hemiparasites endemic to temperate forests of Chile and Argentina that parasitize Nothofagus. This mistletoe is unique in that it has feathery staminodes on its wind dispersed achenes. Previous classifications included two subgenera, Misodendrum (two sections) and Angelopogon (three sections). The present study tested this classification using two chloroplast genes (trnL-F and matK) and 31 morphological characters. Maximum parsimony, likelihood and Bayesian analyses were performed for individual and combined partitions. Results from analyses of the separate partitions differed only in the positions of M. linearifolium and M. quadriflorum; however, the 2-gene tree gave higher support for M. quadriflorum as sister to all other species. Misodendrum brachystachyum and M. oblongifolium form a well supported clade that is sister to one composed of M. punctulatum, M. gayanum, and M. angulatum. These phylogenetic relationships generally agree with previous taxonomic classifications. Subgenus Misodendrum, characterized by warty stems and two stamens, here resolves as a polytomy: M. punctulatum, M. gayanum, and M. angulatum. Subgenus Angelopogon, characterized by the plesiomorphies three stamens and foliacious bracts, is paraphyletic given our rooting. Misodendrum brachystachyum and M. oblongifolium (section Archiphyllum) differ morphologically only by the length of their fruiting staminodes.

We undertook a phylogenetic study of the genus Piptadenia with a sample of 18 of ca. 27 recognized species using DNA sequences from the plastid Trnl-F and trnK/matK regions. Parsimony jackknife results support the hypothesis that Piptadenia is polyphyletic and that there are three independent lineages. The largest groups of species form a monophyletic lineage that is sister to Mimosa and corresponds closely to Piptadenia section Piptadenia sensu Barneby. Three species (P. obliqua, P. moniliformis, and P. leucoxylon) of section Pityrocarpa are sister to species of Pseudopiptadenia in a lineage with Parapiptadenia, Microlobius and Stryphnodendron. Piptadenia viridiflora is distantly related to sects. Piptadenia and Pityrocarpa. Section Piptadenia is characterized by the presence of prickles (aculei), a potential synapomorphy linking it to Mimosa, and exserted, racemose or paniculiform inflorescences of aggregated spikes. Piptadenia viridiflora has stipular spines and 1–2 axillary, spicate primary inflorescences. Species of sect. Pityrocarpa are unarmed trees (sometimes with hardened, persistent stipules) whose flowers have recurved petals and an ovary on a long gynophore. We recommend that Piptadenia viridiflora be removed to a new genus, and that Piptadenia be restricted to the other species of sect. Piptadenia. We resurrect the generic name Pityrocarpa to encompass the Pityrocarpa clade and make the following new combinations: Pityrocarpa moniliformis, Pityrocarpa obliqua ssp. brasiliensis, and Pityrocarpa leucoxylon.

Two new African species of Acalypha (Euphorbiaceae subfamily Acalyphoideae) are described and illustrated. Acalypha guineensis from Guinea and Sierra Leone is most similar to A. manniana, from which it differs by its smaller size, shorter peduncles on the pistillate inflorescences, smaller pistillate bracts with shorter and fewer teeth that are broadly triangular rather than linear-triangular, and velutinous rather than setose ovaries. Acalypha cupricola, endemic to copper-rich soils in the southern Democratic Republic of the Congo, belongs to the same species group as A. clutioides, A. dikuluwensis, and A. fuscescens, but can be distinguished from all three by its greater stature and more densely pubescent leaves. This name previously was a nomen nudum, and we also review other invalid names published by Robyns with A. cupricola.

A comprehensive taxonomic revision of the genus Adelia (Euphorbiaceae s.s.) is presented. Although fourteen species have previously been recorded in the genus, we recognize only nine species based on observations of herbarium material and living plants. The utility of specific taxonomic characters is also evaluated, with particular emphasis on leaf characters as well as characters from staminate and pistillate flowers. Detailed taxonomic descriptions are given for every species including phenological data and iconography. Adelia tenuifolia is excluded from the genus, because it was concluded that it belongs in Bernardia as initially described.

Mespilus and Crataegus are sister genera in Rosaceae tribe Pyreae. Mespilus has been seen to comprise not only the medlar, Mespilus germanica, of western Eurasia but also the Arkansas, U.S.A. endemic, Mespilus canescens. Crataegus, on the other hand, consists of 140–200 species found throughout the northern hemisphere. Diagnoses of these two genera rely on morphological features of leaves, flowers and fruits. However, character states supposed to be diagnostic of Mespilus occur in species of Crataegus. We used two nuclear (ribosomal ITS and LEAFY intron2) and four intergenic chloroplast DNA regions (trnS-trnG, psbA-trnH, trnH-rpl2, and rpl20-rps12) to estimate the phylogeny of Mespilus and Crataegus. Maximum parsimony, maximum likelihood, and Bayesian analyses all corroborate the sister group relationship between Crataegus and Mespilus, and Crataegus brachyacantha sister to the rest of Crataegus. However, incongruence between chloroplast and nuclear data supports the hypothesis of a hybrid origin for Mespilus canescens, with Crataegus brachyacantha or its ancestor as the maternal parent. Accordingly, we (1) restrict Crataegus section Brevispinae to Crataegus brachyacantha (2) distinguish the Arkansas endemic as a nothospecies; (3) describe a new section and a new nothosection within Crataegus to contain the former species of Mespilus and Crataemespilus; and (4) make two new combinations under Crataegus.

Gelsemiaceae consist of two intercontinental disjunct genera: Gelsemium (3 species) and Mostuea (9 species). Gelsemium is distributed in eastern Asia and eastern North America, while Mostuea is disjunct between South America and Africa. In this study, sequences of three chloroplast genes (ndhF, rbcL, and matK) and the external transcribed spacer (ETS) of the ribosomal DNA region were used to examine phylogenetic relationships of Gelsemiaceae. Our results support the monophyly of Gelsemiaceae, Mostuea, and Gelsemium; however, more data are needed to resolve relationships of Gelsemiaceae with other families of Gentianales. Within Mostuea, M. surinamensis of South America is sister to the clade containing African species, indicating that it is unlikely that M. surinamensis is an introduced species from Africa since the morphology of the species is also different from all of the African species. North American species of Gelsemium form a clade that is sister to G. elegans of eastern Asia, which is consistent with flower and fruit morphology. Both Mostuea and Gelsemium show the most common phylogenetic patterns of intercontinental disjunct genera: reciprocal monophyly of species on separate continents.

Phylogenetic relationships among species of the large genus Ruellia (Acanthaceae) have never been studied. Ruellia, with approximately 300 species, is geographically widespread and morphologically diverse. Molecular data for 196 specimens from the nuclear ribosomal ITS region and the chloroplast trnG-trnR region were used to test monophyly of the genus against closely related genera in Ruellieae, to reconstruct phylogenetic relationships among species of Ruellia on a global scale, to re-evaluate previous morphology-based classifications, and to examine the utility of morphological characters, especially corolla morphology, for future sectional delimitation. Bayesian and parsimony analyses indicate four genera are evolutionarily allied to Ruellia. Acanthopale is sister to Ruellia s. l. with strong support. Blechum, Eusiphon, and Polylychnis are nested within Ruellia s. l., and species in Eusiphon and Polylychnis are here formally transferred to Ruellia resulting in the new combinations Ruellia geayi and Ruellia fulgens. Ruellia s. l., including Blechum, Eusiphon, and Polylychnis, is monophyletic but only weakly supported by parsimony. Within Ruellia, Old World taxa form a basal grade and New World taxa are monophyletic and nested within the Old World grade. Alternative hypotheses involving non-monophyly of New World Ruellia were significantly less parsimonious and less likely. Within New World Ruellia, many clades are informally recognized, several of which reflect previous taxonomic groupings to some extent. Constraining all putatively hummingbird-pollinated taxa to monophyly was strongly rejected. This suggests that corolla morphology has undergone convergent evolution and is therefore likely an inappropriate character for sectional delimitation, contrary to previous use.

Tabebuia is one of the most commonly encountered genera of Bignoniaceae in the neotropics. Previous research has suggested that this genus may be paraphyletic and contain the tribe Crescentieae. Molecular sequence data of the chloroplast trnL-F and ndhF regions were used to reconstruct the phylogeny of Tabebuia, Crescentieae and related genera. A previously unrecognized clade of Neotropical, arboreal Bignoniaceae characterized by palmately compound leaves was identified and is referred to as the Tabebuia alliance. Within this group, Tabebuia is confirmed to be paraphyletic, since it includes Crescentieae, Spirotecoma, and Ekmanianthe. The position of Zeyheria, Godmania, and Cybistax with relation to Tabebuia is equivocal. Sparattosperma is sister to the rest of the Tabebuia alliance. Spirotecoma is inferred to be sister to Crescentieae. The phylogeny of Tabebuia presented here corresponds to the species groups established by Gentry, while at the same time highlighting the need for taxonomic revisions. When considered on a biogeographic scale, the phylogeny indicates a minimum of four dispersal events from the mainland to the Greater Antilles.

Recent molecular studies have shown Tabebuia to be polyphyletic, thus necessitating taxonomic revision. These revisions are made here by resurrecting two genera to contain segregate clades of Tabebuia. Roseodendron Miranda consists of the two species with spathaceous calices of similar texture to the corolla. Handroanthus Mattos comprises the principally yellow flowered species with an indumentum of hairs covering the leaves and calyx. The species of Handroanthus are also characterized by having extremely dense wood containing copious quantities of lapachol. Tabebuia is restricted to those species with white to red or rarely yellow flowers and having an indumentum of stalked or sessile lepidote scales. The following new combinations are published: Handroanthus arianeae (A. H. Gentry) S. Grose, H. billbergii (Bur. & K. Schum). S. Grose subsp. billbergii, H. billbergii subsp. ampla (A. H. Gentry) S. Grose, H. botelhensis (A. H. Gentry) S. Grose, H. bureavii (Sandwith) S. Grose, H. catarinensis (A. H. Gentry) S. Grose, H. chrysanthus (Jacq.) S. Grose subsp. chrysanthus, H. chrysanthus subsp. meridionalis (A. H. Gentry) S. Grose, H. chrysanthus subsp. pluvicolus (A. H. Gentry) S. Grose, H. coralibe (Standl.) S. Grose, H. cristatus (A. H. Gentry) S. Grose, H. guayacan (Seemann) S. Grose, H. incanus (A. H. Gentry) S. Grose, H. lapacho (K. Schum.) S. Grose, H. pulcherrimus (Sandwith) S. Grose, H. pumilus (A. H. Gentry) S. Grose, H. riodocensis (A. H. Gentry) S. Grose, H. selachidentatus (A. H. Gentry) S. Grose, H. serratifolius (Vahl) S. Grose, H. spongiosus (Rizzini) S. Grose, H. subtilis (Sprague & Sandwith) S. Grose and H. uleanus (Kraenzl.) S. Grose.

To test the hypotheses that Oreomyrrhis species form the sister clade of North American Chaerophyllum and thus render the mainly Eurasian Chaerophyllum paraphyletic, two chloroplast intergenic spacers (atpB-rbcL and trnS-trnG) were analyzed. Phylogenetic estimates using maximum parsimony, maximum likelihood, and Bayesian inference of separate and combined matrices strongly support the monophyly of Oreomyrrhis and its sister-group relationship with North American Chaerophyllum. Chaerophyllum temulum, the type species of Chaerophyllum, is the sister taxon to the clade composed of Oreomyrrhis and North American Chaerophyllum. Relationships among other major clades of Chaerophyllum are congruent with previous studies. Based on these phylogenetic estimates, all currently recognized taxa of Oreomyrrhis are synonymised with Chaerophyllum. The unranked names, North American clade and Oreomyrrhis clade, are advocated to designate the two well-supported clades within Chaerophyllum sect. Chaerophyllum. The proposed nomenclatural changes include three new names, Chaerophyllum australianum, Chaerophyllum guatemalense, and Chaerophyllum novae-zelandiae, and 26 new combinations, Chaerophyllum andicola, Chaerophyllum argentum, Chaerophyllum azorellaceum, Chaerophyllum basicola, Chaerophyllum borneense, Chaerophyllum brevipes, Chaerophyllum buwaldianum, Chaerophyllum colensoi, Chaerophyllum colensoi var. delicatulum, Chaerophyllum colensoi var. hispidum, Chaerophyllum colensoi var. multifidum, Chaerophyllum daucoides, Chaerophyllum eriopodum, Chaerophyllum gunnii, Chaerophyllum involucratum, Chaerophyllum lineare, Chaerophyllum nanhuense, Chaerophyllum orizabae, Chaerophyllum papuanum, Chaerophyllum plicatum, Chaerophyllum pulvinificum, Chaerophyllum pumilum, Chaerophyllum ramosum, Chaerophyllum sessiliflorum, Chaerophyllum taiwanianum, and Chaerophyllum tolucanum.

Balsamorhiza and Wyethia together comprise 24 species native to western North America. All species in the two genera are perennial herbs with large taproots and chromosome base numbers of x  =  19. The species of Balsamorhiza have exclusively basal leaves while the species of Wyethia have cauline leaves (in addition to basal leaves in some species). The relationships among the species of Balsamorhiza and Wyethia were examined using sequences from the nuclear internal transcribed spacer and external transcribed spacer regions and the chloroplast 3′ trnK intron. Twenty-three species of Balsamorhiza and Wyethia and eight outgroups were sampled. The analyses support the monophyly of the Balsamorhiza/Wyethia clade. Wyethia ovata, a species from southern California and northern Baja California, is sister to the other members of the Balsamorhiza/Wyethia clade. Balsamorhiza is strongly supported as monophyletic and is the sister to the rest of Wyethia. The mostly Californian Wyethia section Agnorhiza, which lacks basal leaves, is not monophyletic. The remainder of the Wyethia species, traditionally placed in sections Alarconia and Wyethia, form a clade in the molecular trees and share synapomorphic large basal leaves.

Encelia, Enceliopsis, and Geraea are three closely related genera of shrubs and herbs distributed in the arid lands of western North and South America. Resolution of relationships within Encelia has traditionally been difficult because there is some morphological overlap among species, and species hybridize when sympatric. In this study, we used DNA sequence data from two nuclear regions (ITS and ETS) and two chloroplast regions (psbA-trnH and trnS-trnfM) to infer phylogenetic relationships among 19 species, subspecies, and varieties of Encelia. Eight species of Enceliopsis, Geraea, Simsia, and Bahiopsis were also included as outgroups. These data support previous hypotheses suggesting that Encelia is monophyletic and sister to Enceliopsis Geraea. In addition, our data provide evidence for two major subclades within Encelia that are supported by morphological synapomorphies. However, little differentiation was observed among species of Encelia within subclades. This lack of differentiation may be the result of a recent diversification of the genus including recent radiation in the Peninsular Desert.