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Medusagyne oppositifolia Baker is the sole member of Medusagynaceae Engl. & Gilg and its phylogenetic position has been unclear. Analysis of rbcL sequence data indicates a close and strongly supported relationship to Ochnaceae and Quiinaceae, but does not resolve the relationships between these taxa. Together the three families form a monophyletic group with a somewhat more distant relationship to other linalean groups including Malpighiaceae, Linaceae and phyllanthoid Euphorbiaceae.

Rhabdodendron is the sole genus in Rhabdodendraceae and affinities have been suggested with Chrysobalanaceae, Rutaceae and Phytolaccaceae. Analysis of rbcL sequence data indicates a placement within Caryophyllidae sensu Chase, Soltis, Olmstead et al. 1993, but without a particularly close relationship to any of the other families. On this basis we support the familial rank Rhabdodendraceae and place it in Caryophyllidae, without reference to a particular order. The molecular results are discussed in the light of the morphological, anatomical and biochemical characters of Rhabdodendron.

Morphogenic responses within the genus Trifolium were investigated by culturing various explants from seedlings of 72 species. Seedlings from 32 species produced callus alone, 40 produced adventitious shoots and/or roots, of which 25 species produced only shoots and 7 species formed only roots. Seedlings within each species also varied in their response to culture. The section of these seedlings most likely to produce adventitious shoots was the original shoot with the remnants of the surrounding hypocotyl and cotyledons, followed by the excised cotyledons themselves.

We are pleased to present you with the first issue of Phytotaxa , a new international journal for botanical taxonomy. Descriptive taxonomy—the discovery and description of taxa—is fundamental to biology and documentation of biological diversity (Wheeler 2007). With the current need to document and monitor biological diversity enshrined in international conventions (e.g. Convention on Biological Diversity, Convention on Migratory Species, 2010 Millennium Development Goals ) it is unfortunate that descriptive taxonomy finds itself marginalised within the scientific community and even in traditional centres of excellence such as natural history museums and universities (Zhang 2006). There is widespread perception among non-taxonomists that description of our flora and fauna was already completed years ago. This contributes to the bias against publications of new taxa.

One of the most perplexing problems in Western European terrestrial orchid taxonomy has been how to deal with the large numbers of taxa that have been described for the allopolyploid taxa, which are the products of hybridization between taxa in the Dactylorhiza maculata (L.) Soó group and the D. incarnata (L.) Soó group. One of the most perplexing problems in Western European terrestrial orchid taxonomy has been how to deal with the large numbers of taxa that have been described for the allopolyploid taxa, which are the products of hybridization between taxa in the Dactylorhiza maculata (L.) Soó group and the D. incarnata (L.) Soó group.

In a series of review articles on polyploid formation, Buggs & al. (2009, 2011) and Soltis & al. (2010) have repeatedly addressed the question of whether hybridization between divergent progenitors drives whole-genome duplication and criticized the conclusions of our paper, Paun & al. (2009: “Hybrid speciation in angiosperms […]”). As the third paper in less than two years has been published in the April issue of Taxon, we take the opportunity to respond and clarify further our conclusions on hybrid speciation. The consistent points of contention in the papers by Buggs, D.E. Soltis and P. S. Soltis referred to two main points: 1) oversimplification of the subject by excluding autopolyploids from our analyses, and 2) misinterpretation of results due to our incomplete analysis of data presented in Paun & al. (2009). We discuss these and other debated topics in the following paragraphs.

Circumscription of Plumbaginaceae is evaluated using sequence data from three plastid regions (rbcL, the intron of trnL and the intergenic spacer of trnL-trnF) and a morphological dataset of 51 characters. Thirteen species representing the major genera of Staticoideae and Plumbaginoideae, as well as one species of Aegialitis, have been analysed using three species of Polygonaceae as an outgroup. Analyses of the molecular, morphological and combined datasets yield similar results. Plumbaginaceae are divided in two well-supported groups corresponding to subfamilies Staticoideae and Plumbaginoideae. Aegialitis is sister to the rest of Staticoideae. In the light of these data, we can conclude that the classification of Plumbaginaceae in two subfamilies is well supported. Moreover, Aegialitis should be regarded as a tribe in Staticoideae.

Here we show with both extensive real and simulated data that rigorous and time-intensive approaches, including parsimony, maximum likelihood and Bayesian methods, to reconstructing large phylogenetic trees are unwarranted with small amounts of data (i.e., single or small numbers, 2-3 genes) because they actually produce trees with scores that are shorter or otherwise less optimal than the model tree or trees produced with larger amounts of data. Furthermore they also fail to obtain consistently more correct groups than simple parsimony methods, leaving the latter to be preferred. When numbers of variable sites are limited relative to numbers of taxa sampled, simpler swapping strategies perform as well as much more rigorous methods. We caution against confidence in any results based on small data sets, even if (or especially if) there have been thorough analyses. Analyses of such data sets for exploratory purposes should rely on simple search strategies and not use excessive branch swapping or time.

Scalesia divisa and S. incisa (Asteraceae), both endemic to the Galapagos Islands, are found only on San Cristobal, where S. divisa grows in the north-west of the island while S. incisa occurs in the north-east. At localities in between, populations with deviating individuals occur. Here we analyse the population structure of S. divisa, S. incisa and two deviating populations based on morphology, AFLP markers and two plastid microsatellite loci. The deviating populations were collected from either side of the island. In a principal components analysis based on morphological characters they appeared to be intermediate between the presumed pure species. When using a discriminant analysis, the two populations that were geographically furthest apart were best discriminated. A Mantel test showed that there was a significant correlation between morphological differentiation and geographical distance, which was also indicated in a distance tree. A second distance tree based on AFLP characters revealed the same topology, but the branches were longer. This was explained by high within-population variation, as demonstrated by AMOVA. Although only a small proportion of the total variance was explained by the between-population component, the populations were distinct enough to be separated by a discriminant analysis. A high level of misclassification was only found between one of the S. incisa populations and one of the deviating populations. The plastid markers supported the results obtained from AFLP. We hypothesize that the pattern of variation is the result of hybridization between two formerly isolated species. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143, 243−254.

Sagina boydii F. B. White (Caryophyllaceae), Boyd's pearlwort, is an enigmatic taxon of unknown geographical origin which is only known in cultivation and is of uncertain taxonomic status. Morphological, cytological and geographical evidence suggests that it is most similar to S. procumbens L. and S. saginoides (L.) H. Karst., but it differs in its compact growth form. Genetically, AFLP analysis shows that it can be included as part of the variation in S. procumbens. In cultivation, it will grow true from seed. Other compact growth forms occur in S. procumbens but do not grow true from seed. As S. boydii is part of the variation in S. procumbens, is of uncertain geographical origin, is known only in cultivation, and grows true from seed, it is best treated as a new cultivar, Sagina procumbens‘Boydii’. A neotype and standard specimen is designated. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147, 203–211.

A phylogenetic analysis of plastid rbcL DNA sequences for 20 species of Vitaceae s.l. (including Leeaceae) and eight outgroups from Dilleniaceae and Santalales is presented. Patterns of floral and vegetative morphology and ontogeny within the family are compared to the phylogenetic trees produced. Despite the limited sampling of large and variable genera, there is a good correspondence with hypothesized floral and vegetative ontogenetic trends, with Leea and Ampelopsis ancestral, Cissus and Ampelocissus intermediate and Vitis most derived. A clade containing Parthenocissus, Tetrastigma, Cyphostemma and Vitis is found in all shortest trees. Cyphostemma and Parthenocissus are shown to be closely related to Vitis, to which clade Tetrastigma and Cayratia comprise the sister clade. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 138, 421–432.

In vitro techniques have a clear role within ex situ conservation strategies for trees and crop genetic resources, particularly where it is important to conserve specific genotypes or where normal propagules such as recalcitrant seed may not be suitable for long-term storage. These involve the use of conventional micropropagation, restricted growth techniques and cryopreservation. Although these techniques have been used primarily with herbaceous species, increasing attention is being given to woody species. Cryopreservation techniques for both woody and herbaceous species and new approaches which do not require freeze-induced cell dehydration, referred to as the ‘encapsulation-dehydration’ and the ‘vitrification’ techniques are described. Illustrative data are presented for the cryopreservation of willow using the encapsulation-dehydration technique.

botanik

Relationships between the closely related island species of Phylica (Rhamnaceae) and a mainland species, P. paniculata, were elucidated using amplified fragment length polymorphisms (AFLPs). Parsimony, neighbor joining, and principal coordinate (PCO) analyses indicated that each of the species studied is distinct. AFLPs were also useful in elucidating the genetic relationships and possible infraspecific origins of different island populations in the Atlantic and Indian Oceans. Phylica nitida on Réunion is likely to have been derived from P. nitida on Mauritius. Although the sampling on New Amsterdam is not extensive, the data are also consistent with the hypothesis that P. arborea on New Amsterdam was derived from a single colonization of P. arborea from Gough Island. Similarly, the Gough Island population appears to have been derived from a single colonization event, but it is so distinct from those on Tristan da Cunha, that there may have been two separate dispersals to Gough and Tristan/Nightingale from different lines of the mainland progenitor. There is also evidence of a recolonization from Gough to Tristan da Cunha. Thus, Phylica arborea is capable of repeated long distance dispersal, up to 8000 km, even though the fruits and seeds are not of a type normally associated with this phenomenon.

The fern genus Tectaria has generally been placed in the family Tectariaceae or in subfamily Tectarioideae (placed in Dennstaedtiaceae, Dryopteridaceae or Polypodiaceae), both of which have been variously circumscribed in the past. Here we study for the first time the phylogenetic relationships of the associated genera Hypoderris (endemic to the Caribbean), Cionidium (endemic to New Caledonia) and Pseudotectaria (endemic to Madagascar and Comoros) using DNA sequence data. Based on a broad sampling of 72 species of eupolypods I (= Polypodiaceae sensu lato ) and three plastid DNA regions ( atpA , rbcL and the trnL-F intergenic spacer) we were able to place the three previously unsampled genera. Our results show that Cionidium , like Ctenitopsis , Fadyenia , Hemigramma and Quercifilix , is embedded in Tectaria , and the monophyly of Tectaria is therefore corroborated only if these segregate genera are included. Hypoderris is sister to Tectaria brauniana and together they are sister to Triplophyllum , which was found to be monophyletic. Despite their morphological similarity with Tectaria , the genera Pleocnemia and Pseudotectaria were placed in Dryopteridoideae. Polypodiaceae subfamily Tectarioideae (former family Tectariaceae) is hereby defined to include Arthropteris , Hypoderris , Pteridrys , Tectaria and Triplophyllum . Aenigmopteris may also belong here, but this genus remains unsampled.

Populations of 64 taxa of Trifolium were assessed for nitrogen fixation and dry matter production with and without added mineral nitrogen. The number of rhizobia per gram of compost capable of inducing nodulation was tested in 7 species and ranged from 3 to 114, showing interspecific variation for nodulation with indigenous rhizobia. In a sample of 8 species, nitrogen fixation was assessed by acetylene reduction and nodule scoring. There was a good correlation (84 %, P ≤ 0.01) between the two methods, and therefore nodule score was used as a measure of nitrogen fixation in the main assessment. There were large differences between populations in terms of shoot and root dry weight, the shoot: root ratio and nodule score. Added nitrate had a significant effect on all characters, increasing shoot dry weight and the shoot: root ratio and decreasing root dry weight and the nodule score. Results showed the importance of assessing legume germplasm with and without added nitrate in locations where suitable rhizobia for the nodulation of exotic species might not be present.

Background Hybridization and polyploidy are potent forces that have regularly stimulated plant evolution and adaptation. Dactylorhiza majalis s.s., D. traunsteineri s.l. and D. ebudensis are three allopolyploid species of a polyploid complex formed through unidirectional (and, in the first two cases, recurrent) hybridization between the widespread diploids D. fuchsii and D. incarnata. Differing considerably in geographical extent and ecological tolerance, the three allopolyploids together provide a useful system to explore genomic responses to allopolyploidization and reveal their role in adaptation to contrasting environments. Results Analyses of cDNA-AFLPs show a significant increase in the range of gene expression of these allopolyploid lineages, demonstrating higher potential for phenotypic plasticity than is shown by either parent. Moreover, allopolyploid individuals express significantly more gene variants (including novel alleles) than their parents, providing clear evidence of increased biological complexity following allopolyploidization. More genetic mutations seem to have accumulated in the older D. majalis compared with the younger D. traunsteineri since their respective formation. Conclusions Multiple origins of the polyploids contribute to differential patterns of gene expression with a distinct geographic structure. However, several transcripts conserved within each allopolyploid taxon differ between taxa, indicating that habitat preferences shape similar expression patterns in these independently formed tetraploids. Statistical signals separate several transcripts - some of them novel in allopolyploids - that appear correlated with adaptive traits and seem to play a role favouring the persistence of individuals in their native environments. In addition to stabilizing the allopolyploid genome, genetic and epigenetic alterations are key determinants of adaptive success of the new polyploid species after recurrent allopolyploidization events, potentially triggering reproductive isolation between the resulting lineages.

Phylogenetic relationships of Limoniastrum and other genera of subfamily Staticoideae (Plumbaginaceae) were studied using parsimony analysis of the plastid gene rbc L, the intron of trn L and the intergene spacer of trnL - trn F. Our analysis showed that Limoniastrum was polyphyletic. Limoniastrum ifniense , in both rbc L and combined data analyses, is sister to Armeria and Psylliostachys , whereas in the trn L-F (intron and spacer combined) analysis it is sister to a clade composed of Acantholimon , Dictyolimon and the remaining species of Limoniastrum. In all analyses, the five remaining species of Limoniastrum (excluding Limoniastrum ifniense ) formed a clade with two groups of species L. monopetalum+L. guyonianum and those sometimes considered as the segregate genus Bubania ( L. feei, L. weygandiorum and L. rechingeri ). Levels of sequence divergence among these three groups of Limoniastrum were greater than for other well supported genera in the family and, in combination with morphological differences and paucity of synapomorphies, led us to conclude that separate generic status for each of the three clades is warranted.

Phylogenetic relationships of the African and Australian Thymelaeaceae were investigated by parsimony analysis of 41 rbcL nucleotide sequences, including 27 genera and several outgroup taxa. In a second analysis, plastid trnL intron and trnL-F intergenic spacer sequences for the same taxa were included as well. The results from the separate analyses produced highly congruent, although not identical, results. Lastly we combined both sequence regions in one analysis to improve resolution and support. Thymelaeaceae are monophyletic with Thymelaeoideae, Aquilarioideae, Gonystyloideae and Gilgiodaphnoideae clearly recognised. Gonystylus and Lethedon are grouped together, contrary to previous studies that placed Lethedon in Aquilarioideae. The molecular evidence does not support monophyly of the largely African genus Gnidia; at least four major lineages could be identified. Pimelea (Australian) is embedded within one of these lineages, and the others are more closely related to Drapetes (New Zealand and South America), Struthiola, Passerina and Lachnaea (all African).

Phylogenetic relationships in subtribe Vellinae (Brassiceae, Brassicaceae) were studied using combined parsimony analysis of nucleotide sequences of nuclear ribosomal internal transcribed spacers (ITS) and morphology. Analyses of 17 taxa of Vellinae, Zillinae and Savignyinae, plus two outgroups from Brassicinae, reveal a main clade consisting of Vella plus Boleum. This group is sister to Euzomodendron, to which Carrichtera and Succowia are successive sisters. Although Euzomodendron, a morphologically distinctive genus, is embedded in Vella in the ITS analysis, it is placed as sister to Vella in the combined analysis. Boleum, however, is included in the Vella clade in all cases, and its segregation at the genus rank is inappropriate. Psychine, a genus thought by some authors to be related to Vellinae, is sister to Savignya (Savignyinae). Zillinae and Savignyinae are sister groups in the combined analysis, and the pair is sister to Vellinae. Biogeographical features can be inferred from the combined analysis. The annual representatives of Vellinae (Succowia and Carrichtera) are widespread in the Mediterranean and Irano‐Turanian territories. Conversely, the woody taxa are narrow endemics growing in either high-elevation environments or dry, steppe habitats of central and southern Spain, northern Morocco and Algeria. A combination of molecular data, morphology, cytology and biogeographical patterns are used for estimating the general evolutionary patterns of the subtribe. # 2000 Annals of Botany Company

Made available in DSpace on 2014-12-03T13:11:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-03-15Bitstream added on 2014-12-03T13:22:48Z : No. of bitstreams: 1 WOS000334462200001.pdf: 3215990 bytes, checksum: dd46986f26d6c543e8b6bb079eb0f676 (MD5) Prance Fellowship in Neotropical Botany under the Kew Latin American Research Fellowship Programme (KLARF) Systematics Research Fund (the Linnean Society) Systematics Research Fund (Systematics Association-UK) International Association for Plant Taxonomy Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) CPS FP Background: Because of their fragmented nature, inselberg species are interesting biological models for studying the genetic consequences of disjoint populations. Inselbergs are commonly compared with oceanic islands, as most of them display a marked ecological isolation from the surrounding area. The isolation of these rock outcrops is reflected in the high number of recorded endemic species and the strong floristic differences between individual inselbergs and adjacent habitats. We examined the genetic connectivity of orchids Epidendrum cinnabarinum and E. secundum adapted to Neotropical inselbergs of northeastern Brazil. Our goals were to identify major genetic divergences or disjunctions across the range of the species and to investigate potential demographic and evolutionary mechanisms leading to lineage divergence in Neotropical mountain ecosystems.Results: Based on plastid markers, high genetic differentiation was found for E. cinnabarinum (F-ST = 0.644) and E. secundum (F-ST = 0.636). Haplotypes were not geographically structured in either taxon, suggesting that restricted gene flow and genetic drift may be significant factors influencing the diversification of these inselberg populations. Moreover, strong differentiation was found between populations over short spatial scales, indicating substantial periods of isolation among populations. For E. secundum, nuclear markers indicated higher gene flow by pollen than by seeds.Conclusions: The comparative approach adopted in this study contributed to the elucidation of patterns in both species. Our results confirm the ancient and highly isolated nature of inselberg populations. Both species showed similar patterns of genetic diversity and structure, highlighting the importance of seed-restricted gene flow and genetic drift as drivers of plant diversification in terrestrial islands such as inselbergs. Inst Bot Nucl Pesquisa Orquidario Estado, BR-04301012 Sao Paulo, Brazil Univ Naples Federico II, Dipartimento Biol, I-80100 Naples, Italy Inst Plant Protect, Consiglio Nazl Ric, I-50019 Fiorentino, FI, Italy Univ Tecn Particular Loja, Dept Ciencias Nat, Loja 1101608, Ecuador Univ Fed Paraiba, Dept Fitotecn, Lab Citogenet Vegetal, Areia, PB, Brazil Royal Bot Gardens, Jodrell Lab, Richmond TW9 3DS, Surrey, England Univ Estadual Paulista, Dept Ecol, Lab Ecol Mol, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Dept Ecol, Lab Ecol Mol, BR-13506900 Rio Claro, SP, Brazil CNPq: 471929/2006-9 CNPq: 4905102013-2 FAPESP: 06/54189-3 FAPESP: 09/52725-3 CPS2009/17411-8 FAPESP: 09/15052-0

The majority of convincingly documented cases of hybridization in angiosperms has involved genetic introgression between the parental species or formation of a hybrid species with increased ploidy; however, homoploid (diploid) hybridization may be just as common. Recent studies, including one in BMC Evolutionary Biology, show that pollinator shifts can play a role in both mechanisms of hybrid speciation. See research article http://www.biomedcentral.com/1471-2148/10/103