Biggest Genus Research Articles

A model for determining ex situ conservation priorities in big genera is provided by analysis of the subgenera of Rhododendron (Ericaceae)

The large size and complex taxonomy of big genera complicates decision making for conservation. We propose that Rhododendron, comprising some 1215 taxa, divided into nine subgenera and many sections, can be used as a model for other big genera. Although Red List assessments placed 715 taxa in a threat category, or listed them as Data Deficient, and moreover Target 8 of the Global Strategy for Plant Conservation requires 75 % of Red List taxa to be held in ex situ collections by 2020, to date there have been few studies of Rhododendron ex situ collections or conservation priorities. Utilising the subgenus structure of Rhododendron as a framework for examining conservation priorities, we analysed the Red List and determined that subgenera Vireya and Hymenanthes have the most acute conservation issues. Examination of taxa in cultivation shows that 844 of 1215 taxa (70 %) are in cultivation, with subgenera varying from 45 to 100 %. Of the 715 Red List taxa, 400 (56 %) are in cultivation, with subgenera varying from 28 to 72 %. Subgenera Vireya and Azaleastrum have the poorest representation in cultivation and should have precedence for ex situ conservation. As no subgenus reaches the requirement for Target 8, further planning is needed for ex situ conservation of Rhododendron. After combining the two analyses, we propose the priorities for ex situ conservation should be ordered (i) Vireya, (ii) Azaleastrum and (iii) Hymenanthes. Finally, we propose five conservation actions for Rhododendron, and summarise our approach as a model for conservation of other big genera.

LAS ESPECIES DE SALVIA (LAMIACEAE) PARA ARGENTINA

Salvia is the biggest genus from Lamiceae, with almost 900 species. In Argentina it is represented by 23 taxa (20 species, one subspecies, and two varieties), four of these are adventive taxa, the rest are native, and one of these is endemic. Species are distributed predominantly in the north region of the territory, reaching the provinces of La Pampa and Mendoza as the southern limit of its distribution. Each of the 23 Salvia taxa present in Argentina is described and illustrated, and a key for their identification is presented. Three new synonyms are proposed, Salvia borjensis new synonym of Salvia nervosa, Salvia durifolia new synonym of Salvia ovalifolia var. ovalifolia and Salvia alba new synonym of Salvia personata, and ten lectotypes are designated for: Salvia approximata, S. arenaria, S. ovalifolia var. villosa, S. pallida, S. procurrens, S. reflexa, S. serrata, S. stachydifolia, S. uliginosa, and Salvia sect. Pycnosphace.

Study on diversity of woody plants in northwest China

The flora of northwest china belongs to the Holarctic Kingdom in Chinese flora, the flora of the south of northwest China belongs to a Subregion in the Central China Region in the Japan China Forest Subkingdom, and the central east belongs to a Subregion in the North China Region in the Japan China Forest Subkingdom, and the southwest belongs to a Subregion the Tibetan Pleteau and the Himalaya China Forest Subkingdom, and the North belongs to a Subregion the Asia Desolate and Boundless Forest Subkingdom. There are 1 729 species (including infraspecific taxon) of woody plants belonging to 103 families and 338 genera (exclude cultivated plants) in northwest China. Among them, there are 57 species belonging to 17 genera and 6 families are of gymnosperm and 1 672 species belonging to 321 genera and 97 families are of angiosperm. In addition, there are 26 Chinese endemic genera and 173 northwest China endemic species. In those plants, the big families and the big genera play important roles. The flora of northwest China can be divided into 15 distribution types and 17 subtypes. Among them, North temperate, Pantropic, E. Asia N. Amer. Disjuncted, E. Asia are important types. Based on the analysis of compositions and the geographical elements and characteristics of the flora, the paper has discussed the major characteristics of the flora as follows: Species are comparatively rich; species and floristic elements are striking difference; the geographical elements of the flora are comparatively complex, and the genera of temperate are the dominant areal types, among them, north temperate play the part of an important role in the flora; the flora is ancient origin; endemic woody plants are comparatively rich; the flora has widely relate to other area, and the flora is the crisscrossing and assembling, mixing and transition of diversified floristic elements.

ChemInform Abstract: The Genus Neolitsea of Lauraceae: A Phytochemical and Biological Progress

AbstractReview: 73 refs.

Phylogeny, identification and nomenclature of the genus Aspergillus

Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, β-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker.

Numerical Taxonomy of Species in the Genus Mallomonas (Chrysophyta) from China

Mallomonas is one of the biggest genera of Chrysophyta. In total, 37 species and 2 varieties have been recorded in China. Because of their narrow ecological optimum, species of this genus are considered as valuable bioindicators. However, taxonomy of Mallomonas remains unclear. We studied the numerical taxonomy of all the species and varieties recorded in China using Ward’s method and the furthest neighbor method based on 52 morphological characters. Shown in the phylogenetic trees, those species could be divided into two major clusters. One cluster includes 5 small clusters and another includes 2. The results of numerical taxonomy are partially consistent with the traditional ones with some divergences. Furthermore, the diversity of silicified scales including shapes and structures was confirmed as the most important character for identification of Mallomonas species.

Erythroxylaceae, Erythroxylum subsessile (Mart.) O.E. Schulz in Espírito Santo: Distribution extension

Erythroxylaceae have tropical and subtropical distribution with four genera and about 250 species. Erythroxylum is the biggest genus of the family with approximately 100 species cited for Brazil. Erythroxylum subsessile (Mart.) O.E. Schulz is a species cited just for Rio de Janeiro state and now first recorded for the state of Espírito Santo, increasing its area of distribution.

Polarizations of isotypical components of Jacobians with group action

We outline a method to compute the type of the induced polarization of an abelian subvariety of a canonically polarized Jacobian of a smooth projective curve. The method works for curves of not too big genus admitting a “large” group of automorphisms. Several examples are given.

A new species of the genus Clubiona Latreille (Araneae, Clubionidae) from Hainan Island, China

The genus Clubiona Latreille, 1804 is the biggest genus of Clubionidae and the only genus reported from China till now. According to Platnick (2011), a total of 578 species have been described from all over the world, of which 100 species were reported from China (Song et al. 1999). Various field collections in Hainan Island, China were carried out by the colleagues of Hubei University in 2010. During these we have found a Clubiona species, which has a wing-shaped femoral apophysis and is described here as new to the science.

Revalidation of the genusTournefortiopsisRusby, (Guettardeae, Rubiaceae) and a newGuettardafrom Costa Rica

Molecular studies carried out by Achille et al. (2006), revealed the polyphyly within the big genus Guettarda and in its relationships. According to the nrDNS ITS sequence analyses the New World Guettardas belong to two different clades. Most of the species forms a well defined large clade, but two species ( G. crispiflora and G. hirsuta ) belong to the different Bobea -clade as a clearly distinct subclade, characterised by a set of important morphological characters. Based on these evidences the segregation of this second group of the New World Guettardas seems to be well argumented under the name of the revalidated and amplified genus of Tournefortiopsis Rusby, effectuating also the necessary new combinations.

Resinanthus, género nuevo de Rubiaceae (Guettardeae)

Molecular studies carried out by Achille et al. (2006), revealed the polyphyly within the big genus Guettarda and in its relationships, among others the polyphyletic character of the genus Stenostomum C. F. Gaertn. studied earlier by Borhidi and Fernandez (1995 a , b ) based on morphological characters. This fact stimulated a re-examination of the traditional Stenostomum genus, which concluded in the separation of the section Resinanthus Borhidi at generic level and its new generic circumscription. The genus is divided into two sections. Sectio Resinanthus contains 15 species of the West Indies, mainly of Cuba and Hispaniola, and the sectio Macresinanthus sect. nov. has one Mexican species.

Revêtements hyperelliptiques d-osculateurs et solitons elliptiques de la hiérarchie KdV

Let d be a positive integer, K an algebraically closed field of characteristic 0 and X an elliptic curve defined over K . We study the hyperelliptic curves equipped with a projection over X, such that the natural image of X in the Jacobian of the curve osculates to order d to the embedding of the curve, at a Weierstrass point. We construct ( d − 1 )-dimensional families of such curves, of arbitrary big genus g, obtaining, in particular, ( g + d − 1 ) -dimensional families of solutions of the KdV hierarchy, doubly periodic with respect to the d-th variable. To cite this article: A. Treibich, C. R. Acad. Sci. Paris, Ser. I 345 (2007).

Book Review

Book Review

Asia, the continent with the highest Umbelliferae biodiversity

A total of 281 genera of the Umbelliferae have been recorded for the Asian continent (out of 469 known genera in the world). The number of species is 2 115. These figures were obtained as a result of critical taxonomic evaluation of taxa in all countries rich in species and genera of the Umbelliferae; the data are stored in the original computer database ASIUM of Moscow University. One of the essential problems was a coordination of the taxonomy of related taxa of adjacent countries, described independently. ASIUM contains information on protologues, typification, citations in regional Floras, monographs and critical publications, synonymy, and geographical distribution (three-level registration — of the country, region and province). The countries with maximal species richness in the Umbelliferae are China (672 spp.), Turkey (Asiatic, 453 spp.), Iran (362 spp.), Russia (Asiatic, 276 spp.), Kazakhstan (234 spp.), India (227 spp.), Afghanistan (198 spp.), Kyrgyzstan (193 spp.), etc. The biggest genera among Asiatic Umbelliferae are Ferula (177 spp.), Bupleurum (156 spp.), Pimpinella (129 spp.), Heracleum (108 spp.), Seseli (104 spp.) and Angelica (87 spp.).

New combinations in Ruschioideae, based on studies inRuschia(Aizoaceae)

Summary: Recent studies in Ruschia and Lampranthus show that a number of species in both big genera do not conform with the critical features of the genera. These deviating species are placed in the genera Amphibolia, Cerochlamys, Eberlanzia, Erepsia, Esterhuysenia, Octopoma, Oscularia, Rhombophyllum, and Zeuktophyllum, and the appropriate new combinations are made; one new species is described. Most genera are treated more extensively; for Ruschia and Lampranthus only the new combinations are given.

The name of the pea: a quantitative history of legume classification

SUMMARYDuring the period from 1753 to 1964, the balance between splitting and lumping (the median genus size) has remained unchanged in five classifications of the Leguminosae (Linnaeus, Persoon, Bentham, Taubert and Hutchinson), which span the period at approximately 50‐year intervals. This is in contrast with the situation in the Gramineae where increased splitting in recent classifications has resulted in smaller median genus size. However, generic sizes in the Leguminosae do not cluster around the median but are uneven: the frequency distribution of genus size in all the classifications is very skew, with many monotypic genera and some exceptionally large genera. This parameter, equality, changes considerably over time with a trend to more inequality of generic size. This is interpreted as a psychohistorical artefact of the classification process with newly discovered species tending to accrete to existing genera which act as‘nuclei’for‘chaining’. The few species which are too anomalous to fit into the large and diverse genera may be placed in monotypic genera, thus producing a pattern of many very small genera and few very big genera. The one exception to this trend is the classification of Bentham which is considerably more even than expected.The three subfamilies of the Leguminosae show similar overall trends to the family as a whole but exhibit consistent differences between each other in median genus size and equality of genus size. The Caesalpinoideae has even genus sizes and a low median genus size whereas the Mimosoideae shows the opposite, effects too marked to be explained entirely as psychohistorical artefact. These differences may be explained partly as artefact and partly in terms of differing evolutionary history if (1) the Caesalpinoideae is an ancient group primarily of relict species which have undergone little recent speciation, (2) the Mimosoideae are an ancient group which has undergone a massive bloom of recent speciation and (3) the Papilionoideae are a comparatively recently evolved group.

MEASUREMENT OF BIOLOGICAL AND HISTORICAL INFLUENCES ON PLANT CLASSIFICATIONS

SummaryPlant classifications have a frequency distribution of taxon sizes which is very skewed (the celebrated “hollow curve” of Willis). In the first part of this paper I suggest that the best general measure of the hollow curve is the variance of the fitted lognormal distribution. By this means we can compare classifications, such as Linnaean classifications with modern ones; the Linnaean classification of the Gramineae is more “lumped” but more “even” than the modern one.In the second part I use phenetic automatic classifications as a model for the classification process to show that (as Walters (1961) has predicted) classifications are heavily influenced by the method used (amount of chaining), but that the biological patterns of character state distribution among organisms also contribute to the hollowness of the curve. Although classifications are influenced by historical factors, underlying biological patterns are still evident in the relative sizes of genera. The model indicates that artificial and “real” components are present in classifications in roughly equal proportions. It seems that Clayton's (1983) phylogenetic “optimism” and Walters' (1986) psycho‐historical “realism” both need modification.Monotypic taxa, in particular, may have a biological meaning. Willis interpreted monotypic genera as nascent and big genera as old. Walters interpreted monotypic genera as young historically and big genera as old historically. I suggest, from relict theory, that monotypic taxa tend to be ancient relicts and large genera tend to represent blooms of recent evolution, and that extinction, not evolution, tends to delimit taxa.