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Genus

About: Genus is a research topic. Over the lifetime, 68921 publications have been published within this topic receiving 590966 citations. The topic is also known as: monospecies genus & genus (zoology).


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Journal ArticleDOI
14 May 2010-Zootaxa
TL;DR: The phylogenetic hypothesis indicates that the genus Chrysaora forms a monophyletic group, with C. achlyos having a basal position in the phylogeny.
Abstract: Revision of the scyphozoan genus Chrysaora Peron & Lesueur, 1810 was undertaken from observations on museum material (Brazil, Europe, and USA), on living specimens in nature, and on life-cycles of some species cultured under laboratory conditions. A total of 168 museum lots, some of them having many medusae, were inspected. Included amongst these were nine type specimens. The genus comprises 13 valid species (Chrysaora achlyos, C. chinensis, C. colorata, C. fulgida, C. fuscescens, C. hysoscella, C. lactea, C. melanaster, C. pacifica, C. pentastoma, C. plocamia, and C. quinquecirrha), one species inquirenda (Chrysaora caliparea), and two doubtful species (C. kynthia and C. wurlerra). Differentiation of species is based mostly on tentacle number, shape of radial septa, order of tentacle development, colouration, and measurements of nematocysts. We resurrect C. chinensis for specimens from southeast Asia. Chrysaora pacifica is considered valid and distinct from C. melanaster based on tentacle number and nematocyst complement. Mediterranean specimens assigned to C. hysoscella are hermaphroditic and thereby considered distinct from those of C. fulgida from west Africa. Chrysaora achlyos (northeast Pacific) and C. plocamia (southeast Pacific and southwest Atlantic) are geographically isolated but morphologically identical, being distinguished only by colour pattern. The recently described C. southcotti is considered a junior synonym of C. pentastoma. The Australian C. kynthia and C. wurlerra, here considered nomina dubia, merit further study. Our phylogenetic hypothesis indicates that the genus Chrysaora forms a monophyletic group, with C. colorata, C. plocamia, and C. achlyos having a basal position in the phylogeny. Species with more than 24 tentacles (formerly assigned to the genus Dactylometra) form a clade with a derived position.

87 citations

Journal ArticleDOI
01 Jan 1987
TL;DR: P Parmelia is an extremely conservative genus, most common in temperate-boreal and austral regions, with a low level of vegetative morph formation and speciation.
Abstract: Hale, Mason E., Jr. A Monograph of the Lichen Genus Parmelia Acharius sensu stricto (Ascomycotina: Parmeliaceae). Smithsonian Contributions to Botany, number 66, 55 pages, 25 figures, 1987.--The 38 species of Parmelia Acharius sensu stricto are revised at the world level. The genus is characterized by punctate or effigurate pseudocyphellae, a black lower surface with simple, furcate or squarrose rhizines, simple hyaline spores, and cylindrical to weakly bifusiform conidia. The most frequent secondary metabolites are salazinic acid and protocetraric acid. Parmelia is an extremely conservative genus, most common in temperate-boreal and austral regions, with a low level of vegetative morph formation and speciation. The greatest concentrations of species are found in Japan and New Zealand. Seven new species are described: P. neodiscordans Hale, P. norcrambidiocarpa Hale, P. novae-zelandiae Hale, P. queemlanderuis Hale, l? salcrambidiocarpa Hale, P. skultii Hale, and P. subtestacea Hale. O ~ C I A L PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution’s annual report, Smithsonian Year. SERIES COVER DESIGN: Leaf clearing from the katsura tree Cercidiphyllum japonicum Siebold and Zuccarini. Library of Congress Cataloging in Publication Data Hale, Mason E., Jr. A monograph of the lichen genus Pannelia Acharius sensu stricto (Ascomycotha: Parmeliaceae) (Smithsonian contributions to botany ; no. 66) Bibliography: p. Includes index. Supt of Docs. no. SI1.29:66. 1 . Parmelia-Classification. 2. Lichens-Classification. I. Title. 11. Series. QKl.SZ747 no. 66 581 s 86607945 [QK585.P2] [589.1]

87 citations

Journal ArticleDOI
TL;DR: Fresh material, type studies and molecular phylogeny were used to clarify phylogenetic relationships of the nine genera Acrocordiella, Blogiascospora, Clypeosphaeria, Hymenopleella, Lepteutypa, Pseudapiospora, Requienella, Seiridium and Strickeria, and all were found to belong to the Xylariales.
Abstract: Fresh material, type studies and molecular phylogeny were used to clarify phylogenetic relationships of the nine genera Acrocordiella, Blogiascospora, Clypeosphaeria, Hymenopleella, Lepteutypa, Pseudapiospora, Requienella, Seiridium and Strickeria. At first sight, some of these genera do not seem to have much in common, but all were found to belong to the Xylariales, based on their generic types. Thus, the most peculiar finding is the phylogenetic affinity of the genera Acrocordiella, Requienella and Strickeria, which had been classified in the Dothideomycetes or Eurotiomycetes, to the Xylariales. Acrocordiella and Requienella are closely related but distinct genera of the Requienellaceae. Although their ascospores are similar to those of Lepteutypa, phylogenetic analyses do not reveal a particularly close relationship. The generic type of Lepteutypa, L. fuckelii, belongs to the Amphisphaeriaceae. Lepteutypa sambuci is newly described. Hymenopleella is recognised as phylogenetically distinct from Lepteutypa, and Hymenopleella hippophaeicola is proposed as new name for its generic type, Sphaeria (= Lepteutypa) hippophaes. Clypeosphaeria uniseptata is combined in Lepteutypa. No asexual morphs have been detected in species of Lepteutypa. Pseudomassaria fallax, unrelated to the generic type, P. chondrospora, is transferred to the new genus Basiseptospora, the genus Pseudapiospora is revived for P. corni, and Pseudomassaria carolinensis is combined in Beltraniella (Beltraniaceae). The family Clypeosphaeriaceae is discontinued, because the generic type of Clypeosphaeria, C. mamillana, is a member of the Xylariaceae. The genus Seiridium, of which the sexual morph Blogiascospora is confirmed, is unrelated to Lepteutypa, as is Lepteutypa cupressi. The taxonomy of the cypress canker agents is discussed. The family Sporocadaceae is revived for a large clade of the Xylariales that contains Hymenopleella, Seiridium and Strickeria among a number of other genera. Neotypes are proposed for Massaria fuckelii and Sphaeria hippophaes. Didymella vexata, Seiridium marginatum, Sphaeria corni, Sphaeria hippophaes, Sphaeria seminuda are epitypified, Apiosporina fallax, Massaria occulta, Sphaeria mamillana and Strickeria kochii are lecto- and epitypified. We also provide DNA data for Broomella vitalbae, Cainia desmazieri and Creosphaeria sassafras.

87 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20232,790
20226,199
20212,431
20202,299
20192,015
20182,000