A new species of Sphagnum section Subsecunda, S. beringiense , is described from arctic Alaska from the vicinity of Barrow along the northern coast. The species is distinguished morphologically by the light, yellow-green color of the gametophytes, multistratose stem cortex with 2–4 layers of enlarged thin-walled cells, round, medium-size (ca. 5 μm diameter) outer branch leaf pores, scattered inner branch leaf pores, typically few outer stem leaf pores, and abundant, round to elliptic inner stem leaf pores. Two unique plastid DNA haplotypes occur among Barrow area plants of S. beringiense , and these differ by a minimum of three nucleotide substitutions from those of other Alaskan Sphagnum species in the section Subsecunda. Microsatellite markers show that S. beringiense is genetically variable despite the fact that all plants were sampled from within an area of a few km² and neither gametangia nor sporophytes have been observed. A key to the six Alaskan species of Sphagnum section Subsecunda is provided.

Hemlock, Tsuga (Pinaceae), has a disjunct distribution in North America and Asia. To examine the biogeographic history of Tsuga, phylogenetic relationships among multiple accessions of all nine species were inferred using chloroplast DNA sequences and multiple cloned sequences of the nuclear ribosomal ITS region. Analysis of chloroplast and ITS sequences resolve a clade that includes the two western North American species, T. heterophylla and T. mertensiana, and a clade of Asian species within which one of the eastern North American species, T. caroliniana, is nested. The other eastern North American species, T. canadensis, is sister to the Asian clade. Tsuga chinensis from Taiwan did not group with T. chinensis from mainland China, and T. sieboldii from Ullung Island did not group with T. sieboldii from Japan suggesting that the taxonomic status of these distinct populations should be reevaluated. The Himalayan species, T. dumosa, was in conflicting positions in the chloroplast and ITS trees, suggesting that it may be of hybrid origin. Likelihood-based biogeographic inference with divergence time estimates infers an Eocene basal crown group diversification and an initial widespread circumpolar distribution with subsequent vicariance and extinction events leading to the current disjunct distribution.

Recently published molecular phylogenies of the Annonaceae have confirmed the long-held hypothesis that the large paleotropical genus Polyalthia is polyphyletic. Species previously assigned to Polyalthia are now known to belong to up to six distinct, generally well-supported clades. Three members of a group of six species previously referred to as the Polyalthia hypoleuca complex form a monophyletic group (with 99% bootstrap support) that is only distantly related to the other species of Polyalthia sampled. Putative morphological synapomorphies are assessed, and justification provided for validating a new generic name, Maasia . Six species names in the Polyalthia hypoleuca complex are accordingly transferred to Maasia: M. discolor, M. glauca, M. hypoleuca, M. multinervis, M. ovalifolia, and M. sumatrana .

The current infrafamilial taxonomy of the Iridaceae recognizes four subfamilies; Isophysidoideae (1: 1); Nivenioideae (6: ca. 92), Iridoideae (29: 890), and Crocoideae (29: 1032). Phylogenetic analyses of sequences of five plastid DNA regions, rbcL, rps4, trnL–F, matK, and rps16, confirm most aspects of this classification and the evolutionary patterns that they imply, importantly the sisiter relationship of Isophysidoideae to the remainder of the family and the monophyly of Iridoideae. Subfamily Nivenioideae is, however, paraphyletic; Crocoideae is consistently found nested within it, sister to the core Nivenioideae, the woody Klattia, Nivenia, and Witsenia. This clade is sister to Aristea, which in turn is sister to the Madagascan Geosiris, and then to the Australasian Patersonia. We treat Aristea, Geosiris, and Patersonia as separate subfamilies, Aristeoideae and the new Geosiridaceae and Patersonioideae, rendering Nivenioideae and Crocoideae monophyletic. The alternative, uniting a widely circumscribed Nivenioideae and Crocoideae, seems undesirable because Nivenioideae have none of the numerous synapomorphies of Crocoideae, and that subfamily includes more than half the total species of Iridaceae. Main synapomorphies of Crocoideae are: pollen operculate; exine perforate; ovule campylotropous; root xylem vessels with simple perforations; rootstock a corm; inflorescence usually a spike; plants deciduous. Four more derived features of Crocoideae are shared only with core Nivenioideae: flowers long-lived; perianth tube well developed; flowers sessile; and septal nectaries present. The genera of the latter subfamily are evergreen shrubs, have monocot-type secondary growth, tangentially flattened seeds, and the inflorescence unit is a binate rhipidium. The latter feature unites core Nivenioideae with Aristea, Geosiris, and Patersonia, which have fugaceous flowers and, with few exceptions, a blue perianth. Molecular-based phylogenetic trees using sequences from five plastid DNA regions now show discrete generic clusters within Crocoideae and Iridoideae, the foundation for the tribal classification. The five tribe classification of Iridoideae, initially based on morphological characters and subsequently supported by a four plastid DNA region sequence analysis, continues to receive support using additional DNA sequences. Application of molecular clock techniques to our phylogeny indicates that the Iridaceae differentiated in the late Cretaceous and diverged from the next most closely related family, Doryanthaceae circa 82 mya, thus during the Campanian. The Tasmanian Isophysis is the only extant member of the clade sister to the remainder of the Iridaceae, from which it may have diverged 66 mya, in the Maastrichtian. The generic phylogeny shows the proximal clades of the family are all Australasian, which corroborates past hypotheses that the Iridaceae originated in Antarctica-Australasia, although its subsequent radiation occurred elsewhere, notably in southern Africa and temperate and highland South America at the end of the Eocene or later.

The monotypic genus Tamia was described by Ravenna in 2001 based on specimens of Calydorea pallens from Bolivia and West-Central Argentina (excluding Córdoba and San Luis). At the same time, Ravenna described Calydorea undulata as a new species to accommodate the excluded specimens. He used floral morphology to segregate Tamia from Calydorea. He described Calydorea as having the anthers twisted/circinate after dehiscence, whereas in Tamia, the anthers are straight. Similarly, in Tamia the upper third of the anther is adnate to the style arms while in Calydorea the anthers are free from the style branches. We here evaluate the validity of Tamia and C. undulata based on morphological and cytological approaches. An examination of living plants of both taxa showed the anthers to be straight during dehiscence and twisted when the pollen was exposed, likewise the stamens were completely free from style branches in both taxa. Both have a base chromosome number of x = 7 (C. undulata diploid, 2n = 14; T. pallens tetraploid, 2n = 28). The karyotype formula for C. undulata was 5 m 2 sm and 7 m 7 sm for T. pallens. The karyotype is bimodal in C. undulata and moderately asymmetrical in T. pallens. These chromosomal differences and differences in petal shape (the outer are flat for both taxa while the inner are geniculate in T. pallens but flat with undulate margins in C. undulata) and flower color (pale lilac with dark violet dots in T. pallens and violet-blue with violet stripes in C. undulata) suggest that these taxa are distinct species of Calydorea, where a polyploid series based on x = 7 is known. The divergence of their karyotypes is within the observed chromosomal variability of genera in Iridaceae. Thus, we conclude that Tamia should be regarded as a synonym of Calydorea, with the return of its species to Calydorea pallens, because the floral differences between them are not enough to merit generic segregation. Calydorea undulata is nonetheless a valid species.

Nuclear ribosomal DNA (nrDNA) has been used for more than a decade in species level phylogenetic analyses. While nrDNA can often be a powerful phylogenetic marker, intraindividual polymorphisms of the internal and external transcribed spacers (ITS, ETS) can lead to problems in their use for phylogeny reconstruction. Incomplete concerted evolution coupled with hybridization and incomplete lineage sorting can further exacerbate these problems. Previous phylogenetic analyses using nrDNA of Carex subgenus Vignea suggest that the current sectional classifications may be highly artificial. We endeavored to identify what influence incomplete concerted evolution, lineage sorting, and hybridization have played in the complex patterns of relationships previously inferred from ITS and ETS sequences for subgenus Vignea. Through comprehensive cloning we identified high levels of intraindividual polymorphisms and in many cases this led to the polyphyly of individuals. Furthermore, individuals identified with novel mutations in the 5.8S ribosomal subunit did not show a significant deviation in G-C percentage and free energy. Based on these results we suggest that nrDNA contains multiple paralogs in many species and clades within Carex subgenus Vignea which greatly complicates its use for phylogenetic inference of relationships and future studies in Carex need to take this into account.

We used a combination of amplified fragment length polymorphisms (AFLP) and morphological data from 272 individuals from 59 populations to investigate the species-level taxonomy of Carex roanensis and allied species. There were two taxonomic problems in this group: identifying the appropriate taxonomic status for Carex roanensis, and clarifying the distinctions (if any) between C. virescens and C. swanii. Principal coordinate analysis of the morphological data suggested four entities corresponding to C. aestivalis, C. roanensis, C. swanii, and C. virescens, but clear discrimination was not possible. In contrast, the AFLP data showed marked discontinuities among these four species, placing even morphological intermediates into one of four groups. Analysis of molecular variance revealed significant population differentiation within each species, but only C. virescens had any detectable differentiation between geographic regions. This study confirms the species-level distinction between the common and widespread taxa C. swanii and C. virescens, as well as that of the globally rare Appalachian endemic C. roanensis.

The Distichlis clade comprises Distichlis (7 species), Monanthochloë (2), and Reederochloa (1). All species except D. distichophylla (endemic to Australia) and D. spicata (widespread in the New World) are restricted either to North or South America. We investigated phylogenetic relationships within the clade using chloroplast (trnL–F and ndhF) and nuclear ribosomal (internal transcribed spacers and 5.8S) DNA sequences. We also studied lemma micromorphology, leaf blade anatomy, macromorphology, and biogeography in a phylogenetic context. The Distichlis clade is strongly supported in the molecular analyses. A morphological synapomorphy for the clade is the presence of a single papilla on the center of each subsidiary cell of lemma stomata. Other diagnostic features include dioecy, rhizomes or stolons, conspicuously distichous leaves, 5–13 lemma nerves, dumbbell- or flask-shaped bicellular microhairs with sunken basal cells, and growth in alkaline or saline soils. The nuclear and chloroplast phylogenies indicate that Monanthochloë and Reederochloa are nested within a paraphyletic Distichlis, and a number of structural characters, including leaf blade length, number of spikelets per inflorescence, and number of florets per spikelet, also fall within the range of variation in Distichlis. Therefore, we propose expanding the circumscription of Distichlis to include Monanthochloë and Reederochloa, and make the following new combinations: Distichlis acerosa, D. eludens , and D. littoralis . Biogeographical analysis revealed that the group likely originated in North America followed by a number of long-distance dispersal events, including back dispersals.

A new morning glory from the northern-most reaches of tropical forests in North America, Merremia cielensis , is described and illustrated. This narrow endemic from Tamaulipas, Mexico, shares close relationships with a complex of yellow-flowered merremias that produce indehiscent capsules with translucent pericarps. Merremia cielensis can be readily distinguished from all other Mexican merremias on the basis of cordate leaves, a ruddy, accrescent calyx during fruition, and a four-seeded capsule.

During a revision of Solanum section Erythrotrichum, four species, two from Brazil and two from Peru, were recognized as new and are described here. Solanum absconditum, from northeastern and northern Brazil, is similar to S. paludosum. It differs in its cordate to cordate-lanceolate, acuminate, and weakly bicolorous leaf blades that are yellowish to ferruginous above, the corolla tube 4–6 mm long, and the epicarp with stipitate-stellate trichomes. Solanum eitenii, from the “cerrado” of Maranhão, Brazil, resembles both S. decompositiflorum and S. rhytidoandrum, from which it can be distinguished by its long and pendent inflorescence and its calyx with a very short tube and oblanceolate lobes. Solanum megaspermum, from Peru, has similarities with S. mesopliarthrum, from which it differs by the triangular and very short calyx lobes (1.5–2 mm) and the scabrous and deciduous indumentum with somewhat stiff porrect-stellate trichomes. Solanum urubambaense from Cuzco, Peru, is similar to the Bolivian S. abutilifolium, but differs by its oblong-lanceolate anthers, strigose ovary, and trichomes with a reduced central ray. The species are described, illustrated and compared with similar species; commentaries on their affinities and distribution are also included. A key to the species of the section Erythrotrichum is provided.

There are about 190 wild potato (Solanum L. section Petota Dumort.) species distributed from the southwestern United States to central Argentina and adjacent Chile and Uruguay. The morphological similarity of many of its constituent species has led to widely conflicting taxonomic treatments. Solanum series Piurana Hawkes is one of 21 series recognized in section Petota in the latest comprehensive taxonomic treatment by Hawkes in 1990. They are distributed from southern Colombia, south through Ecuador to central Peru. The limits of the series and validity of its constituent species are unresolved. We provide the first comprehensive morphological phenetic study of the series, to include putatively related species in ser. Conicibaccata, Cuneoalata, Ingifolia, Megistacroloba, Simplicissima, Tuberosa, and Yungasensa, through an examination 188 living germplasm accessions of 33 species, planted in replicated plots in a field station in Andean Peru. Only four morphologically well-defined groups were supported. Continuing work is exploring molecular support for these species in these eight series.

solanum medians is a widely distributed species of wild potato (solanum sect. petota), growing along the coastal lomas and up the western slopes of the Andes Mountains from central Peru and northern Chile, from 200–3800 m elevation. Fertile diploid and sterile triploid cytotypes are common, are believed to be associated with morphological variants, and are formally named as subspecies. A morphometric study based on principal components and canonical discriminate analyses of characters obtained from herbarium specimens tests the circumscription of these subspecies and other currently recognized species that are very similar to S. medians. The results show so much overlap of these taxa that it is impractical to use morphology to define species or to provide reliable keys or identifications. We synonymize ten names under S. medians: S. medians var. angustifoliolum, S. medians var. majorifrons subvar. majorifrons, S. medians var. majorifrons subvar. protohypoleucum, S. medians var. autumnale, S. sandemannii, S. tacnaense, S. weberbaueri var. decurrentialatum, S. tacnaense f. decurrentialatum, S. weberbaueri, S. weberbaueri var. poscoanum. We also treat S. neoweberbaueri as a closely related species to S. medians. We consider the synonymy in S. medians to be part of a much larger need for reduction of names in sect. petota.

Incongruence among different estimates of species relationships in plants, from different molecules, cytogenetic data, biogeographic data, morphological/anatomical data or other sources, has been used frequently as an indication of introgression, hybrid species origin, or chloroplast (cp) capture. In plants, these incongruences are most often seen between data derived from the nuclear vs. the cp genomes and the nuclear markers used for comparison usually have been from the nuclear ribosomal (nr) internal transcribed spacer region (ITS). The amount of genomic material shared between introgressing species can be highly variable. In some of these cases, other nuclear genomic regions have moved between species without leaving a signature on the nrITS. An example of well-supported phylogenetic incongruence is the placement of Dubautia scabra (DC.) D. D. Keck in the Hawaiian silversword alliance (HSA); evolutionary hypotheses for D. scabra based on molecular as opposed to cytogenetic data are strongly discordant. In this paper, we test these two conflicting phylogenetic hypotheses regarding the evolutionary relationships of Dubautia scabra using evidence from six low-copy nuclear genes, as well as multiple chloroplast noncoding regions and nrITS. The nrITS region is also examined for the presence of multiple copy types. Incongruence between inferred relationships based on nuclear chromosomal arrangements and molecular phylogenetic data from chloroplast DNA and nrITS is resolved in favor of a hypothesis of ancient hybridization rather than cytogenetic homoplasy involving dysploidy. Most single-copy nuclear genes track histories of D. scabra compatible with cytogenetic data whereas chloroplast and nrITS data track a common, different history that appears to reflect hybridization with a chromosomally distinct lineage that also occurs on Maui Nui and Hawai‘i (the Big Island).

Menyanthaceae consist of five genera of aquatic and wetland plants distributed worldwide. The three monotypic genera (Liparophyllum, Menyanthes, and Nephrophyllidium) are clearly differentiated morphologically, but the two larger genera (Nymphoides and Villarsia) contain several taxa of uncertain affinity. We undertook a phylogenetic analysis, using a combination of morphological and molecular data, to resolve relationships among species and to evaluate the current circumscription of genera. DNA sequence data for nuclear (ITS) and chloroplast (rbcL and trnK/matK) gene regions were largely congruent (by partition-homogeneity test), and a combined data phylogeny revealed several strongly supported relationships. Analyses using asterid outgroup taxa supported the monophyly of Menyanthaceae. Menyanthes trifoliata and Nephrophyllidium crista-galli comprised a clade sister to the remainder of the family. Species of Nymphoides, except N. exigua, resolved to a single, deeply-nested clade, indicating that the floating-leaved habit is derived evolutionarily within the family. The genus Villarsia comprised a paraphyletic grade toward Nymphoides, wherein the species resolved to three assemblages: (1) a shallowly nested clade containing V. albiflora, V. calthifolia, V. marchantii, V. parnassifolia, V. reniformis, and V. umbricola; (2) an isolated South African clade including V. manningiana and the type species, V. capensis; and (3) a heterogeneous clade of taxa from three genera, including V. exaltata, V. lasiosperma, and V. latifolia, plus the anomalous species V. capitata, V. congestiflora, Liparophyllum gunnii, and Nymphoides exigua. Our results indicate that the genera Menyanthes, Nephrophyllidium, and Nymphoides should be retained as circumscribed, with the exception that Nymphoides exigua should be restored to Villarsia. The genus Villarsia, however, eventually should be subdivided among monophyletic lineages, whereby in the strict sense Villarsia would contain only South African taxa.