Resolving phylogenies among closely related species remains a perplexing problem in plant systematics. All too often cpDNA and nrDNA ITS are insufficiently variable to provide desired resolution or support. In the present study, we have adopted a RAPD-based approach to develop sequence-characterized regions, from the nuclear genome, with levels of DNA sequence variation appropriate for resolving relationships within subclades of Leucaena (Fabaceae). RAPDs were used to amplify a set of seven Leucaena accessions. Equal length fragments amplified in two or more species were sequenced and compared. Specific primers were designed for aligned product sets displaying similar or greater levels of variation than have been found in previous ITS studies. Two regions whose DNA sequences provided greater resolution and bootstrap support than ITS or cpDNA RFLP restriction site data sets for the same sample of Leucaena species are discussed in detail.

Collections of plant specimens are the basic infrastructure for all studies of plant diversity, but there is concern that plant collecting is in decline. We acquired collection data from a diverse sample of 71 herbaria to test whether there is a decrease in rates of local collecting in the United States. The recorded data were the decade of collection for all specimens of nine exemplar genera from the local region of the herbarium. All analyses showed evidence of a decline in local collecting. We found that the temporal pattern of collecting varied considerably from herbarium to herbarium, but that more herbaria showed a decreasing trend than an increasing trend. The total accumulation of specimens is in decline and only 21% of the sampled herbaria reached their peaks in local collecting activity in the last 20 years. Furthermore, two thirds of the herbaria acquired fewer locally-collected specimens in the last two decades than in the prior two. These trends were consistent over all size classes of herbaria and over herbaria from all regions, though they were less severe in the Mountain region herbaria. Tests for bias indicated that our sample of herbaria was more active than typical, thus our conclusions should be considered a conservative estimate of decline.

The haplolepideous mosses (Dicranidae) constitute a large group of ecologically and morphologically diverse species recognised primarily by having peristome teeth with a single row of cells on the dorsal surface. The reduction of sporophytes in numerous moss lineages renders circumscription of the Dicranidae problematic. Delimitation of genera and higher taxa within it has also been difficult. We analyse chloroplast-encoded rps4 gene sequences for 129 mosses, including representatives of nearly all the haplolepideous families and subfamilies, using parsimony, likelihood and Bayesian criteria. The data set includes 59 new sequences generated for this study. With the exception of Bryobartramia, which falls within the Encalyptaceae, the Dicranidae are resolved in all analyses as a monophyletic group including the extremely reduced Archidiales and Ephemeraceae. The monotypic Catoscopium, usually assigned to the Bryidae is consistently resolved as sister to Dicranidae, and this lineage has a high posterior probability under the Bayesian criterion. Within the Dicranidae, a core clade is resolved that comprises most of the species sampled, and all analyses identify a proto-haplolepideous grade of taxa previously placed in various haplolepideous families. The data provide considerable resolution of relationships within the core Dicranidae, yielding a number of well-supported clades. These correspond only roughly to taxa that are currently recognised, and most families and orders of Dicranidae apparently are non-monophyletic under their current circumscriptions.

A new genus and species, Craibella phuyensis (Annonaceae), is described from Kanchanaburi Province, western Thailand. Craibella is a genus of small trees with pendent, unisexual flowers; the petals are in two whorls, with the larger inner whorl forming a mitriform dome over the reproductive organs. It is suggested that the genus is most closely related to Pseuduvaria and Orophea, but is distinguished from both by the combination of leaf-opposed inflorescences, elongated-conical torus in staminate flowers, and unusual staminal connectives that are apically expanded but do not extend distally over the thecae. Other significant differences include unisexual flowers, distinguishing Craibella from Orophea, and solitary pollen grains (monads), distinguishing it from Pseuduvaria.

Phylogenetic relationships within the orchid genus Pleione were reconstructed using maximum parsimony analyses of plastid and nuclear DNA and morphology for 20 taxa to evaluate infrageneric groups, controversial species delimitations, and parentage of several putative wild hybrids. Separate analyses of each data set produced mainly congruent clades when P. × confusa and the Chinese accession of P. hookeriana were excluded. Analysis of the combined data indicated that traditional divisions of the genus into various subgenera and sections are supported when they are based on apomorphic characters. Sections found to be paraphyletic appear to be based on homoplasious and plesiomorphic characters. For an infrageneric classification of Pleione based on phylogenetic relationships three groups are suggested. Taxa within the P. bulbocodioides complex do not show much molecular divergence. Pleione maculata and P. praecox are proposed to be the paternal and maternal parent of P. × lagenaria, respectively, as their nuclear and plastid genomes were almost identical to their natural hybrid. Furthermore, DNA sequences confirm the paternal and maternal parent origin of P. × confusa from P. forrestii and P. albiflora as already suggested by morphological and karyotype data. Molecular data are not conclusive about parentages of P. × taliensis.

Two new species, one new variety, and a new combination of Froelichia are described from North America. Froelichia xantusii from Baja California Sur is being recognized as a species endemic to southern Baja California and separate from F. interrupta in which it had been previously included. Within F. interrupta two varieties are here recognized, the newly described Froelichia interrupta var. colimensis from southern Nayarit to Oaxaca and the new combination Froelichia interrupta var. alata from the Sonoran Desert. Froelichia latifolia is described from eastern Texas and has been segregated from the widespread F. floridana. A key to the genus in North America is also included.

Gooseberries are often distinguished from currants as a distinct genus (Grossularia) or subgenus (Ribes subg. Grossularia), but recent molecular phylogenetic analyses of chloroplast and nuclear data disagree as to the monophyly of this group. We report new sequence data from the 18–26S nuclear rDNA ITS and ETS regions and from the chloroplast psbA-trnH intergenic spacer that, in combination with previously reported data, suggest subg. Grossularia is monophyletic and nested within Ribes. Two main lineages are evident within subg. Grossularia, corresponding to the true gooseberries (subg. Grossularia sect. Grossularia) and a clade of glabrous-styled western North American gooseberries (subg. Grossularia sect. Robsonia, subg. Hesperia, Lobbia). Biogeographic analyses based on DIVA optimizations suggest a western North American origin for subg. Grossularia, with subsequent dispersal to east Asia giving rise to a well-supported clade of Asian gooseberry species in sect. Grossularia. This example contrasts with the well-documented pattern of dispersal from Asia to North America, and highlights the need to investigate additional groups distributed widely through the Northern Hemisphere.

The Krameriaceae is a monotypic family of 18 species distributed in the warm arid and semiarid regions of North and South America. We have used sequence data from the internal transcribed spacer region of the nuclear ribosomal DNA repeat (ITS 1, 5.8S, and ITS 2) and morphology to infer relationships within Krameria. Using Kallstroemia parviflora, Guaiacum angustifolium, and Tribulus terrestris, three North American members of the Zygophyllaceae, as outgroups, our data provide evidence for two major clades in the genus, each containing a North and a South American subclade. Both the major clades and subclades are supported by morphological synapomorphies. The phylogeny does not provide an unequivocal resolution as to the hemisphere in which Krameria arose, but it does indicate an initial split leading to the ancestors of the two clades, each of which subsequently produced radiations in North and South America. Therefore, there must have been two independent dispersals to, or two vicariant episodes involving, North and South America.

Two new monotypic genera of Podostemaceae are illustrated and described: Cipoia (C. inserta) and Diamantina (D. lombardii). Both are known only from the state of Minas Gerais, Brazil, where they occur attached to rocks in the swift currents of river-rapids and waterfalls. Diamantina is the only genus of Podostemaceae that produces pollen in tetrads. Diamantina lombardii is distinguished from all other New World members of the family by its digitate leaves and prominent gynophore. Cipoia inserta is distinguished from other New World species with dyad pollen by a single stamen per flower and by the ovary and mature capsule remaining enclosed within the ruptured spathella during and after anthesis; only the stigmas and stamens project from the spathella.

Resumo. Dois novos gêneros monoespecíficos de Podostemaceae são ilustrados e descritos: Cipoia (C. inserta) e Diamantina (D. lombardii). Ambas espécies são conhecidas somente para o Estado de Minas Gerais, Brasil, onde ocorrem fixas às rochas em corredeiras ou quedas d'água. Quatro gêneros de Podostemaceae do Novo Mundo produzem pólen em diades: Ceratolacis, Cipoia, Crenias e Podostemum. Diamantina é o único gênero de Podostemaceae que produz pólen em tétrades. Diamantina lombardii também se distingue de todos os outros membros da família no Novo Mundo pelas suas folhas digitadas e pelo ginóforo proeminente. Cipoia inserta se distingue das outras espécies com pólen em diades do Novo Mundo por possuir um único estame por flor e pelo ovário incluído junto com a espatela rompida durante a ântese, somente os estígmas e os estames se projetam da espatela. A cápsula se desenvolve através da espatela rompida.

The non-succulent, leafy species of Euphorbia from Madagascar have received considerably less attention from taxonomists than the succulent Euphorbia species. The lack of a recent synthetic taxonomic treatment for this group makes it almost impossible to accurately name these species. As part of an ongoing revision of the genus in Madagascar, Euphorbia randrianjohanyi and Euphorbia rauhii, two new species closely allied to the Malagasy endemic E. pervilleana are described, and a key to these three species is provided. This group is distinguished by echinate 1–2-locular capsules. It is closely related to other Malagasy species such as E. tetraptera, which possesses 2-locular capsules with four wings. The three species are dioecious and their deciduous leaves can make some specimens difficult to distinguish; however they can be separated by their allopatric distribution, the length of interglandular appendages, the shape and size of the leaves, as well as by fruit features. They all occur in the central and southern part of the island.

Micrandra inundata is a distinctive new species adapted to seasonally flooded black-water river banks in southern Venezuela. Trees rarely exceed 10 m in height but have thick basal trunks composed of very lightweight wood. It has the smallest leaves and fruits of any known Micrandra species and appears to be most closely related to M. minor Benth. The botanical description is accompanied by habit photographs, line illustrations of morphological features, and photomicrographs and detailed descriptions of the wood anatomy.

Cardamine amara, an Eurasian species comprising several subspecies, was examined through morphometric and amplified fragment length polymorphism (AFLP) analyses to re-evaluate subspecific status of tetraploid C. amara subsp. olotensis from Catalonia (NE Spain) and to resolve the taxonomic position of Central Italian populations usually placed within C. amara and/or C. raphanifolia s. l. A presumptive close relative from the Caucasus, diploid C. wiedemanniana, was also analyzed for AFLPs. Morphometric results show Catalonian and Italian populations to be similar to each other, but distinct from other C. amara. With both principal coordinate analysis and the neighbour-joining tree based on AFLP data, three main groups are delimited: (1) tetraploid Catalonian C. amara subsp. olotensis and Italian populations, (2) all other diploid and tetraploid subspecies of C. amara, and (3) diploid C. wiedemanniana. As a result of this study, Italian and Catalonian populations are herein treated as a single species, C. amporitana, distinct from C. amara. Catalonian populations appear genetically depauperate, perhaps having experienced bottlenecks during Pleistocene glaciation, or originating via long-distance dispersal from the Apennine Peninsula.

Onagraceae are a family of 17 genera in seven tribes, with the majority of species in tribes Onagreae and Epilobieae. Despite the species-richness of these two tribes, to date no phylogenetic study has been done with sufficient taxon sampling to examine relationships between and within these tribes. In this study, we used DNA sequence data from one nuclear region (ITS) and two chloroplast regions (trnL-trnF and rps16) to infer phylogenetic relationships among 93 taxa across the family, with concentrated sampling in the large tribe Onagreae. Results strongly suggest that tribe Gongylocarpeae is sister to tribes Epilobieae Onagreae, both of which are monophyletic. Within Onagreae, Camissonia seems to be broadly paraphyletic, and Oenothera is also paraphyletic. In Oenothera there appear to be two lineages, one of which has Gaura Stenosiphon nested within it. At the base of the Onagraceae phylogeny, we have clarified previous confusion regarding conflicting placements of Hauya and Lopezia based on nuclear versus chloroplast data. Results of these analyses are supported by morphology and suggest the need for new taxonomic delimitations, which are forthcoming.

Penstemon subgenus Dasanthera is a group of nine species distributed at high elevations in western North America. Hybridization is common in the subgenus when two or more species occur in sympatry. We examined evolutionary trends and the importance of hybridization to the evolution in the subgenus. Phylogenetic and biogeographic patterns among members of Penstemon subgenus Dasanthera were assessed using nuclear ribosomal ITS and chloroplast matK sequence data, and inter-simple sequence repeat (ISSR) markers. These data support previous hypotheses suggesting that the Cascade-Sierra Nevada lineage is derived from the northern Rocky Mountain lineage. Furthermore, there is a shift in growth form from suffructescent perennials to evergreen subshrubs concurrent with migration to the Cascade-Sierra Nevada mountains. Within the Cascade-Sierra lineage, P. newberryi and P. rupicola exhibit floral characters that may represent adaptations for hummingbird pollination. The ISSR data demonstrate the utility of dominant markers for reconstructing phylogenetic relationships at the interspecific level.

Solanum section Lasiocarpa includes about a dozen species with a center of diversity in the New World tropics. Solanum lasiocarpum and S. repandum (sometimes considered to be conspecific as S. ferox) have an Old World distribution in Asia and the Pacific Islands. Several species in this section produce edible fruits, and two, the lulo or naranjilla (S. quitoense) and the cocona (S. sessiliflorum) are cultivated commercially. Phylogenetic relationships in Solanum section Lasiocarpa were investigated using sequence data from the chloroplast trnT-trnL spacer, the trnL-trnF spacer, and the trnL gene, including the trnL intron. Sampling included 24 accessions from section Lasiocarpa and 14 accesssions of other Solanum species as outgroups. All species considered to belong to section Lasiocarpa by previous authors were examined with the exception of the recently described S. atheniae. Solanum robustum and S. stagnale, sometimes considered to belong to section Lasiocarpa, are excluded from the group on the basis of the trn data. The remaining species in the section form a monophyletic group, with three well-supported clades within it: S. hirtum, S. pectinatum-sessiliflorum-stramonifolium, and the remainder of the species in the section. Sequences of S. lasiocarpum and S. repandum are extremely similar, and these two Asian taxa cluster with the New World S. candidum and S. pseudolulo on the trn trees.

Phylogenetic analyses of chloroplast trnK intron and nuclear ribosomal ITS DNA sequences yield significant improvements in our understanding of relationships, character evolution, and biogeography in Viburnum (Adoxaceae). We confirm that most of the ten traditionally recognized sections are monophyletic. The most striking exception is Odontotinus, which is divided into: (i) a purple-fruited New World clade within which the Latin American section Oreinotinus is nested, and (ii) an Old World, mostly red-fruited clade that is closely related to V. cylindricum (section Megalotinus) and the New World, purple-fruited V. acerifolium. We identify three major supra-sectional groupings: (i) a clade consisting of the Odontotinus-Oreinotinus-Megalotinus complex, the circum-boreal section Opulus, and the Eurasian section Tinus, (ii) a clade containing the Old World section Viburnum, the New World section Lentago, and, with less support, section Pseudotinus, and (iii) a clade containing the Asian sections Tomentosa and Solenotinus. Two species are not clearly allied to any of these supra-sectional clades: V. urceolatum, a Taiwanese/Japanese species traditionally placed in section Viburnum, and V. clemensiae, a Bornean species previously assigned to section Solenotinus. The placement of the root also remains uncertain, but probably does not fall within any of the three major supra-sectional clades. Knowledge of relationships within sections is useful in clarifying historical biogeography and the evolution of sterile flowers and fruit color. The one case of conflict between datasets highlights a possible instance of homoploid hybrid speciation.

Established concepts of Chrysothamnus have been primarily based on morphological similarity or on molecular studies employing only exemplar taxa. Those investigations and treatments conceptualized Chrysothamnus as a single evolutionary unit with affinity for Ericameria, Petradoria, and Stenotus among other taxa. The hypotheses of relationship presented here are based on nuclear ribosomal 3′ ETS and ITS data that were analyzed using several optimality criteria. The results indicate that Chrysothamnus as traditionally perceived is polyphyletic, with species placed in four well-supported lineages. Three of the four clades also contain taxa from other genera. Seven species of Chrysothamnus along with Acamptopappus, Amphipappus, Hesperodoria scopulorum, Tonestus lyallii, and Vanclevea constitute one clade, while four species aggregate in another clade that includes Hesperodoria salicina, Tonestus microcephalus, and T. peirsonii. A third lineage consists of Chrysothamnus gramineus and appears distantly related to any other Chrysothamnus. Finally, four species of Chrysothamnus recently transferred to Ericameria are strongly supported within the Ericameria lineage. Stenotus and Tonestus as traditionally circumscribed are not supported by the molecular data. Instead, the generitype of each is aligned with taxa other than species presently included within the same genus. The results of this investigation indicate that some of the morphological features used to delimit these genera may be the product of convergence, thus diminishing their value for phylogenetic reconstruction.