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1.
Taxonomic complexity has hindered partitioning the genusCentaurea into natural subdivisions, even though it has long been recognized as an unwieldy, artificial assemblage. Most of the remaining difficulties center in theCentaurea jacea group, whose taxa share a common advanced type of pollen. Because it comprises half the species of the genusCentaurea, as well as five other disputed genera previously segregated fromCentaurea (Chartolepis, Cheirolepis, Cnicus, Grossheimia andTomanthea), theCentaurea jacea group is a significant taxonomic challenge. Newer molecular approaches are useful for resolving complex relationships because they provide more precise inferences of evolutionary relationships than traditional morphological characters. Sequences of the Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA were analyzed for a comprehensive sample of this group. Results indicated that theCentaurea jacea group is monophyletic and includes the segregated genera, but not two other genera (Oligochaeta andZoegea), whose inclusion in theCentaurea jacea group was doubtful. In addition to pollen morphology, the ITS phylogeny is also supported by karyological evidence and by good correlation with biogeographic distribution of the species. The monophyly of theCentaurea jacea group suggests that a natural delimitation ofCentaurea that minimizes nomenclatural changes is possible, but only if a new type of the genus is designated.  相似文献   

2.
Detailed studies of various aspects of the morphology and reproduction ofAntithamnion subcorticatum Itono andAntithamnion crouanioides Itono show that these species are incorrectly referred to as the genusAntithamnion. To include these species, a new genus,Balliella, is proposed. In addition, some other algae possibly referable to this genus are briefly discussed. The genusBalliella is here recognized as a member of the new tribeDelesseriopsieae which is most nearly related to the tribe Antithamnieae in the Ceramiaceae. The tribe Delesseriopsieae is now recognized to include the two genera, i.e.,Delesseriopsis andBalliella.  相似文献   

3.
Gloeoheppiais re-established as a separate taxon; the genus differs fromHeppiain apothecial development and thallus structure.Gloeoheppiaand the related generaGudeliaHenssen andPseudopeltulaHenssen described here are placed in the new familyGloeoheppiaceaein theLichinales. In habit, the genera ofGloeoheppiaceaeresemble species ofHeppiaandPeltula, whereas in apothecial development they correspond to some extent to theLichinaceae. The speciesGloeoheppia polysporaHenssen,Gloeoheppia rugosaHenssen,Pseudopeltula dicyanophoraHenssen,Pseudopeltula heppioidesHenssen,Pseudopeltula myriocarpaHenssen andGudelia mexicanaHenssen, are described for the first time. InGloeoheppiaceaethe thalli are ecorticate and the hyphae reticulately branched. The prototunicate asci contain eight, or up to 16, colourless and simple, occasionally two-celled spores. In species ofPseudopeltula, the apothecia are of a complex structure. The cyanobionts are small and single-celled; inP. dicyanophora‘internal cephalodia’ with an additional, filamentous cyanobiont are formed. Lectotypes are designated forEndocarpon turgidumAch. andHeppia furvaHue in Patouill.  相似文献   

4.
The genusLepidauchen is discussed and defined. It is removed from the family Lepocreadiidae and placed in the family Acanthocolpidae based mainly on its possession of a uterine seminal receptacle. The type, and only valid species,L. stenostoma, is redescribed using material fromLabrus merula from Corsica. Material fromCoris julis andSymphodus tinca from the western Mediterranean off Marseille,L. merula from the western Mediterranean off Valencia,Diplodus annularis andLithognathus mormyrus from the Adriatic Sea off Montenegro, andArchosargus unimaculatus from Venezuela was also examined. Other nominal species are discussed, but none are considered valid within this genus.  相似文献   

5.
Peter Goldblatt 《Brittonia》1975,27(4):373-385
The native bulbous Iridaceae of North America excluding Mexico comprise seven species in four genera. The type species ofAlophia Herb. (1836) is shown to belong toEustylis Engelm. & Gray (1836), hence the latter genus is reduced to synonymy. The well known genusAlophia (sensu auct. non Herb.) (Herbertia Sweet) now takes the nameTrifurcia. As a result of the new interpretation ofAlophia, new combinations are made for the North American and Latin American species ofTrifurcia andAlophia. New chromosome counts are given forNemastylis floridana (2n = 56) andTrifurcia lahue (2n = 56).  相似文献   

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8.
A study of the branching of the inflorescence and the vegetative shoot of the genusKummerowia, consisting ofK. stipulacea (Maxim.) Makino andK. striata (Thunb.) Schindler, has led to the following conclusions: (1) the inflorescences of both species are reduced compound cymes, (2) the branching system of the inflorescence ofKummerowia is not clearly different from that of the vegetative shoot and there are some transitional forms between both systems, and (3) the inflorescence ofKummerowia is different from the racemose inflorescences ofLespedeza andCampylotropis. Based on the differences found in the branching system of the inflorescence,Kummerowia is distinctly separated fromLespedeza andCampylotropis and is more correctly treated as a distinct genus from the latter two.  相似文献   

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The genusCancelloceras (family Gastrioceratidae) comprises three subgeneraCancelloceras, Crencelloceras n. subgen. andMonitoceras differing in conch ornamentation.Cancelloceras is cosmopolitan and regarded as the index genus for the Upper Namurian G1 Zone, the Yeadonian. The lower boundary of the G1 Zone is defined by the entry ofCancelloceras (Crencelloceras) branneroides, whereas the first representatives of the genus appeared earlier, in the Middle Namurian R2 Zone. The upper boundary of the G1 Zone is marked by the extinction ofCancelloceras and the entry of its descendant genusGastrioceras. Cancelloceras comprises 27 species.  相似文献   

11.
As a result of a review of the Costaceae for theManual de las Plantas de Costa Rica, two new species ofCostus (C. ricus andC. osae) are here described and illustrated. The assignment of the new species ofCostus subgen.Costus is discussed.  相似文献   

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13.
The flies of genusGlossina (Diptera: Glossinidae) are an important vector of African trypanosomiases which cause diseases in humans and animals. The ribosomal DNA Internal Transcribed Spacer-2 (ITS-2) region sequences from differentGlossina species were PCR-amplified and analyzed in order to construct a molecular phylogeny for genusGlossina. Trees generated by parsimony confirmed the monophyletic taxonomic placement of genusGlossina wherefusca group species formed the deepest branch followed bymorsitans andpalpalis groups, respectively. The placement ofGlossina austeni by both the traditional morphological and biochemical criteria has been controversial. Results presented here, based on ITS-2 locus sequence analysis, suggest thatGlossina austeni can be placed into a separate subgenerus which forms a sister-group relationship with themorsitans group species.  相似文献   

14.
Two new speciesGuzmania herrerae andG. scandens, that have been mistakenly identified asG. dissitiflora are described and illustrated. All three taxa belong to a natural complex of species that corresponds to the formerly recognized segregate genusMassangea E. Morren. However, without additional morphological and molecular evidence we believe it is premature to recognize this species complex as a genus separate fromGuzmania.  相似文献   

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A new caprellid species, Caprellinoides singularis, is described and illustrated based on the material collected on the Polarstern Cruise ANT XVII/3 from the Branfield Strait. The most striking characteristic of this species is the presence of bilobed gills on pereonites 3 and 4. The genus Caprellinoides is revised. Caprellinoides antarctica Schellengerg, 1926 and Caprellinoides spinosus Barnard, 1930 are considered junior synonyms of Caprellinoides tristanensis Stebbing, 1888 and Caprellinoides mayeri (Pfeffer, 1888), respectively. The new species, C. singularis, is compared with the remaining species in the genus Caprellinoides: C. tristanensis and C. mayeri, which are illustrated in detail. Received in revised form: 4 June 2001 Electronic Publication  相似文献   

17.
A. Spencer Tomb 《Brittonia》1972,24(2):223-228
Prenanthella is re-established as a genus distinct fromLygodesmia on the basis of morphological, palynological, and chromosomal data. Possible relationships ofPrenanthella to other Stephanomerinae and to the genusCrepis are suggested.  相似文献   

18.
Two new species are added toCryptochloa,C. unispiculata from Peru andC. capillata from Brazil, the latter transferred from the genusOlyra. The genusPiresia is also augmented by two new species,P. macrophylla from Peru andP. leptophylla from Bahia, Brazil. These species represent, respectively, the westernmost and easternmost limits of distribution of the genus.  相似文献   

19.
A new genus,Siemensichthys, from the Upper Jurassic of southern Germany is described. The new genus includes two species,S. macrocephalus (Agassiz) which was formerly in the genusPholidophorus, andS. siemensi n. sp. The two species share synapomorphies such as only one supramaxillary bone covering the dorsal margin of the maxilla. Both species are described, and their phylogenetic position is analyzed. The phylogenetic analyses, based on 27 taxa and 141 characters, show thatAnkylophorus from the Kimmeridgian of Cerin,Siemensichthys andEurycormus from the Solnhofen Lithographic Limestone of Bavaria, form a monophyletic group. The new extinct clade (preliminarily identified as theSiemensichthys- group) is proposed as the sister-group ofPholidophorus s. str. plus more advanced teleosts. This sister-group relationship is supported by eight characters (e.g., supraoccipital bone extending forward in the roof of the otic region; articular bone fused with both the angular and retroarticular; presence of an elongated posteroventral process of quadrate; presence of dorsal processes at the base of the innermost caudal rays of upper lobe; mobile premaxillary bone). Comparisons with species ofPholidophorus s. str. provide a new understanding of the genusPholidophorus. At least four synapomorphies are proposed to support the monophyly ofPholidophorus. As a consequence of this new interpretation, the European Late Jurassic species previously assigned to the Pholidophoridae and to the genusPholidophorus (e.g., ‘Ph.’armatus, ‘Ph.’ falcifer, ‘Ph.’ micronyx, ‘Ph.’ microps) should be reexamined because they do not belong to the family nor to the genus. The order PholidophoriformesBerg is not a monophyletic group as currently constructed. Therefore, all so-called pholidophoriforms are in need of revision.  相似文献   

20.
The genusBalduina, endemic to the southeastern United States as interpreted here, includes a complex of three species:B. atropurpurea Harper,B. angustifolia (Pursh) Robinson, andB. uniflora Nutt. The first two species have a chromosome number ofn = 18 andB. uniflora hasn = 36. Hybridization experiments demonstrated strong internal reproductive isolating mechanisms. Flavonoid and sesquiterpene lactone data suggest a possible relationship to the tribe Helenieae.  相似文献   

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