The origin of the H, St, W, and Y genomes in allotetraploid species of Elymus L. and Stenostachys Turcz. (Poaceae: Triticeae)

Based on sequences from two single-copy nuclear genes (DMC1 and EF-G), four plastid genes (rbcL, rpoA, matK, and ndhF), and one mitochondrial gene (coxII), we investigate the origin of the H, St, W, and Y genomes in four allotetraploid species of Elymus and two allotetraploid species of Stenostachys. Despite significant incongruence between the two nuclear genes and between the nuclear and organelle data partitions, individual and combined analyses of the data partitions unequivocally show that the St and H genomes of the tetraploid American species of Elymus are derived from Pseudoroegneria and Hordeum, respectively, with Pseudoroegneria serving as the female parent, and that the H and W genomes of Stenostachys are derived from Hordeum and Australopyrum, respectively, with Hordeum serving as the female parent. The analyses equally clearly demonstrate that the St genome of the tetraploid Asiatic Elymus species is derived from Pseudoroegneria, with the latter serving as the female parent, but the relationship of the Y genome is less clear. Individual analyses of the nuclear genes provide conflicting results, but combined analysis of all data suggests a sister group relationship to Heteranthelium, albeit without any jackknife support.     

A revision of the West Indian species of Lepanthes (Orchidaceae). III. Cuba

A study of herbarium material ofLepanthes indicates that there are at least 18 species on Cuba. The history of the collections and publications on the genus from the island is summarized, and a detailed key to the species is given. One new combination is proposed (L. blepharophylla) and the following species are described as new:L. acunae,L. dressleri,L. cubensis,L. grisebachiana,L. obliquiloba, andL. occidentalis, of which three are from western provinces and two have been associated with inappropriate names.L. mandibularis Reichb. f. is tentatively considered a synonym ofL. chrysostigma Lindl. although the type ofL. mandibularis could not be found. The range of variation included under the nameL. fulva Lindl. suggests that more than one species is involved.     

New taxa and combinations in Malvastrum A. Gray (Malvaceae: Malveae)

The genusMalvastrum A. Gray is interpreted to include 22 taxa in 14 species. Seven taxa are here described as new, namely:M. americanum var.stellatum,M. tomentosum subsp.pautense,M. bicuspidatum subsp.campanulatum,M. bicuspidatum subsp.oaxacanum, M. bicuspidatum subsp.tumidum var.tumidum, M. bicuspidatum subsp.tumidum var.glabrum, andM. coromandelianum subsp.fryxellii. In addition, two new combinations are proposed, namely:M. tomentosum andM. coromandelianum subsp.capitato-spicatum.     

New genera and species of ericaceae (Vaccinieae) from Costa Rica and Panama

Two new monotypic genera,Didonica andUtleya, are described, withD. pendula from Panama andU. costaricensis from Costa Rica.Disterigma trimera (Panama),D. utleyorum (Costa Rica, Panama, Colombia, and Ecuador),Lateropora santafeensis (Panama),Lysiclesia panamensis (Panama),Macleania talamancensis (Costa Rica),Themistoclesia costaricensis (Costa Rica) andT. horquetensis (Panama),Vaccinium costaricense andV. orosiense (both from Costa Rica) and V.jefense (Panama) are all described as new. New combinations are provided for the PanamanianVaccinium floccosum (=Symphysia floccosa) and the West IndianVaccinium racemosum (=Symphysia racemosa). Keys are provided for the Central American species ofDisterigma andThemistoclesia, the species ofLateropora andLysiclesia, and the Costa Rican and Panamanian species ofVaccinium. Six new species are illustrated.     

Mycopteris,a new neotropical genus of grammitid ferns (Polypodiaceae)

Mycopteris, a new genus of grammitid ferns, is described and combinations are made for the species that belong to it. Mycopteris is diagnosed by castaneous rhizome scales with turgid cells, usually pectinate laminae, blackish petioles and rachises, blackish pinna costae and veins, reddish setae, cretaceous hydathodes, glabrous sporangia, and the presence of Acrospermum ascomes. It is entirely neotropical, ranging from Mexico east into the West Indies and south to Bolivia. Mycopteris is one of two genera of grammitid ferns that are consistently associated with Acrospermum, an epibiotic ascomycete that produces black clavate fruiting bodies. Seventeen species of Mycopteris are recognized here, including one new species (M. longipilosa) and one elevated from the rank of variety to species (M. costaricensis). The following additional combinations are made here: M. alsopteris, M. amphidasyon, M. attenuatissima, M. cretata, M. grata, M. leucolepis, M. leucostica, M. longicaulis, M. pirrensis, M. praeceps, M. semihirsuta, M. steyermarkii, M. subtilis, M. taxifolia, and M. zeledoniana. Lectotypes are chosen for Ctenopteris leucosticta, Polypodium amphidasyon, and Polypodium pectinatum var. hispidum. For each accepted species, full synonymy and geographical range are provided. Taxonomic discussion is provided for species not widely recognized in previous treatments.     

Phylogeny and genetic diversity of D-genome species of Aegilops and Triticum (Triticeae, Poaceae) from Iran based on microsatellites, ITS, and trnL-F

Cereal species of the grass tribe Triticeae are economically important and provide staple food for large parts of the human population. The Fertile Crescent of Southwest Asia harbors high genetic and morphological diversity of these species. In this study, we analyzed genetic diversity and phylogenetic relationships among D genome-bearing species of the wheat relatives of the genus Aegilops from Iran and adjacent areas using allelic diversity at 25 nuclear microsatellite loci, nuclear rDNA ITS, and chloroplast trnL-F sequences. Our analyses revealed high microsatellite diversity in Aegilops tauschii and the D genomes of Triticum aestivum and Ae. ventricosa, low genetic diversity in Ae. cylindrica, two different Ae. tauschii gene pools, and a close relationship among Ae. crassa, Ae. juvenalis, and Ae. vavilovii. In the latter species group, cloned sequences revealed high diversity at the ITS region, while in most other polyploids, homogenization of the ITS region towards one parental type seems to have taken place. The chloroplast genealogy of the trnL-F haplotypes showed close relationships within the D genome Aegilops species and T. aestivum, the presence of shared haplotypes in up to three species, and up to three different haplotypes within single species, and indicates chloroplast capture from an unidentified species in Ae. markgrafii. The ITS phylogeny revealed Triticum as monophyletic and Aegilops as monophyletic when Amblyopyrum muticum is included.     

Revision of Plerandra (Araliaceae). I. A synopsis of the genus with an expanded circumscription and a new infrageneric classification

Phylogenetic studies have demonstrated that Schefflera, the largest genus of Araliaceae, is grossly polyphyletic, comprising five distinct clades within the family. In an effort to establish monophyletic genera among the elements that currently comprise Schefflera, the genus Plerandra is expanded to encompass all of the members of one of these clades. In this synoptical revision, a new infrageneric classification is presented (along with a key) in which six subgenera are recognized. Four of these subgenera are newly described (Plerandra subgenera Canacoschefflera, Costatae, Gabriellarum, and Veilloniorum) and a fifth represents a new combination (Plerandra subg. Dizygotheca). A total of 33 species (one with two subspecies) are accepted, one of which is newly described (P. veilloniorum), and 22 new combinations are made (P. actinostigma, P. baillonii, P. cabalionii, P. costata, P. crassipes, P. elegantissima, P. elongata, P. emiliana, P. gabriellae, P. leptophylla, P. nono, P. osyana, P. osyana subsp. toto, P. pachyphylla, P. pancheri, P. plerandroides, P. polydactylis, P. reginae, P. seemanniana, P. tannae, P. vanuatua, P. veitchii). Neotypes are provided for six accepted names and one heterotypic synonym, and lectotypes are designated for 13 accepted names and 16 heterotypic synonyms. For each accepted species, full synonymy is provided along with geographic range and notes.     

Sphaeromeria,a genus closer to Artemisia than to Tanacetum (Asteraceae: Anthemideae)

A new species,Sphaeromeria ruthiae, from Zion National Park, and three new combinations,S. martirensis,S. compacta, andS. potentilloides var.nitrophila, are presented. Morphological and anatomical evidence is used to support the recognition ofSphaeromeria as distinct fromTanacetum.     

Evidence for several genomes in Helianthus

Forty taxa belonging to 36 species and four unclassified accessions of Helianthus were studied using RAPD technology. Single ten-mer primers were screened for those amplifying fragments common to several species. We found that when several species shared a common fragment, they belong to the same section of the genus. Moreover, we also found that some fragments are common to all species of the Helianthus. Most of the fragments were found to be of the same size in these species and to share the homology indicated by molecular hybridization. Out of 118 retained fragments, 33 were common to all Helianthus species, 56 were unique to perennial species of sects. Atrorubentes and Ciliares, 24 were unique to sect. Atrorubentes, 29 were unique to sect. Helianthus, whereas 0 were unique to sect. Ciliares. Each set of common or specific fragments was assumed to belong to a genome: (1)?the C genome carrying the fragments common to all species of the three sections, (2)?the H genome unique to sect. Helianthus, (3)?the P genome common to perennial species (sects. Atrorubentes and Ciliares), and (4)?the A genome unique to sect. Atrorubentes. The genomic structure was therefore HC for sect. Helianthus, CPA for sect. Atrorubentes, and CP? for sect. Ciliares. Molecular hybridizations with amplification products revealed homologies between Helianthus genomes and several other genera in the Helianthinae sub-tribe. The simple method used to characterize these fragments led to powerful tools for recognizing genomes which reconcile the section organization of the genus and the degree of difficulty in crossing perennial and annual forms.     

The Tvv1 retrotransposon family is conserved between plant genomes separated by over 100 million years

Key message

Combining several different approaches, we have examined the structure, variability, and distribution of Tvv1 retrotransposons. Tvv1 is an unusual example of a low-copy retrotransposon metapopulation dispersed unevenly among very distant species and is promising for the development of molecular markers.

Abstract

Retrotransposons are ubiquitous throughout the genomes of the vascular plants, but individual retrotransposon families tend to be confined to the level of plant genus or at most family. This restricts the general applicability of a family as molecular markers. Here, we characterize a new plant retrotransposon named Tvv1_Sdem, a member of the Copia superfamily of LTR retrotransposons, from the genome of the wild potato Solanum demissum. Comparative analyses based on structure and sequence showed a high level of similarity of Tvv1_Sdem with Tvv1-VB, a retrotransposon previously described in the grapevine genome Vitis vinifera. Extending the analysis to other species by in silico and in vitro approaches revealed the presence of Tvv1 family members in potato, tomato, and poplar genomes, and led to the identification of full-length copies of Tvv1 in these species. We were also able to identify polymorphism in UTL sequences between Tvv1_Sdem copies from wild and cultivated potatoes that are useful as molecular markers. Combining different approaches, our results suggest that the Tvv1 family of retrotransposons has a monophyletic origin and has been maintained in both the rosids and the asterids, the major clades of dicotyledonous plants, since their divergence about 100 MYA. To our knowledge, Tvv1 represents an unusual plant retrotransposon metapopulation comprising highly similar members disjointedly dispersed among very distant species. The twin features of Tvv1 presence in evolutionarily distant genomes and the diversity of its UTL region in each species make it useful as a source of robust molecular markers for diversity studies and breeding.     

Three New Species of Vernonia (Compositae: Vernonieae) from Mexico

Three new Mexican species ofVernonia,V. macphersonii,V. pugana andV. tequilana, are described.     

New species of grasses in Arberella,Cryptochloa, and Raddia (Poaceae: Bambusoideae: Olyreae)

Two new species are described inArberella, one from Panama (Arberella lancifolia) and one from Bahia, Brazil (a. bahiensis), the latter representing a considerable extension of the known range of the genus.Cryptochloa decumbens, described from Panama, brings to ten the species recognized in this genus andRaddia angustifolia, from Bahia, increases to five the number of species in that genus. Each new species is fully illustrated and keyed.     

Four new species of genus Cordia (Cordiaceae, Boraginales) from Brazil

We describe four new species of Cordia (Cordiaceae) from Brazil: Cordia fusca, C. glabrifolia, C. restingae, and C. tarodae. These are illustrated, and data on habitat, phenology, and distribution are provided.     

A taximetric study of infraspecific variation in autogamous Limnanthes floccosa (Limnanthaceae)

Limnanthes floccosa Howell is a variable autogamous species of recent origin. The phenetic relationships of a large number of populations ofL. floccosa were studied using taximetric techniques. Five subspecies are recognized inL. floccosa on the basis of the taximetric results.Limnanthes floccosa ssp.californica andL. floccosa ssp.grandiflora are described as new, andL. floccosa ssp.pumila andL. floccosa ssp.bellingeriana are proposed as new combinations. Aspects of autogamy responsible for the highly discrete pattern of variation inL. floccosa are discussed.     

New taxa and nomenclatural changes in arceuthobium (viscaceae)

The following new taxa are recognized inArceuthobium: subgeneraArceuthobium andVaginata; sectionsVaginata, Campylopoda, andMinuta; seriesCampylopoda,Rubra, andStricta; speciesA. apachecum,A. californicum,A. guatemalense,A. hondurense, andA. pini; new formae spécialesA. abietinum f. sp.concoloris,A. abietinum f. sp.magnificae. New combinations:A. abietinum (Engelm.) Hawksworth & Wiens, andA. microcarpum (Engelm.) Hawksworth & Wiens.     

Rubiacearum Americanarum Magna Hama Pars XXXII. New Species and a New Combination in Coussarea (Coussareeae) from Western South America

The Neotropical genus Coussarea is species-rich and widely distributed but not well known. Seven new species are described here, documented mainly by recent botanical exploration: C. acrensis is found in western Brazil, C. boliviensis and C. mexiae in the mountains of northwestern Bolivia, and C. camposiana, C. maranonensis, C. pseudopilosula, and C. vasqueziana in Peru. The new combination C. insolita is based on Rudgea insolita from Colombia.     

Generic delimitations of Central American Bignoniaceae

Generic delimitations in the Bignoniaceae are discussed, a number of Central American genera are reduced to synonymy, and a new genusPseudocatalpa is proposed. Generic mergers includeLevya withCydista, Saldanhaea withCuspidaria, Doxantha withMacfadyena, Pseudocalymma withPachyptera, andPhaedranthus withDistictis. New combinations necessitated by these mergers include the following:Arrabidaea costaricensis (Kränzl.) Gentry,A. pubescens (L.) Gentry,Cuspidaria floribunda (DC.) Gentry,C. weberbaueri (Spr.) Gentry,Cydista aequinoctialis var.hirtella (Benth.) Gentry,Distictis buccinatoria (DC.) Gentry,Macfadyena unguiscati (L.) Gentry,Melloa quadrivalvis (Jacq.) Gentry,Pachyptera alliacea (Lam.) Gentry,P. hymenaea (DC.) Gentry,P. kerere var.incarnata (Aubl.) Gentry,P. standleyi (Steyerm.) Gentry, andPseudocatalpa caudiculata (Standl.) Gentry. In addition, the fruits of several species are described for the first time, and their taxonomic significance is discussed.     

New species and combinations in Odontonema (Acanthaceae)

Six new species ofOdontonema are described:Odontonema album, O. amicorum, O. breedlovei, O. laxum, O. mortonii andO. speciosum. In addition two new combinations are proposed forOdontonema,O. glaberrimum andO. nitidum var.album, and nine species are transferred fromOdontonema to other acanthaceous genera, namelyAnisacanthus ramosissimus, Buceragenia foliaceo-bracteata, Pseuderanthemum cuspidatum, P. hookerianum, P. interruptum, P. paniculatum, P. stenostachyum, Stenostephanus longistaminus andStreblacanthus dubiosus.