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1.
The Cainotheriidae are small artiodactyls that suddenly appeared in the late Eocene of western Europe. A revision of early Oligocene cainotheriid lineages is proposed on the basis of newly dated material from the Quercy Phosphorites (south-western France). A significant diversification of the group occurred at the end of the Eocene. Few species seem to have persisted through the Eocene/Oligocene boundary, but the Cainotheriidae subsequently diversified rapidly during the early Oligocene.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 145−166.  相似文献   

2.
Based on multivariate analyses, a new dioecious species of Poa from the Puneña and Altoandina phytogeographical provinces of Argentina is described. This species is most similar to Poa calchaquiensis of Poa section Dioicopoa . The ligule length, plant size, and glabrous pistillate anthoecia distinguish Poa nubensis . A key for identification and illustrations are also included.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 239–248.  相似文献   

3.
Elaphoglossum praetrepidans M. Kessler, characterized by long-creeping rhizomes with entire rhizome scales, ill-defined phyllopodia, linear-elliptic, firmly chartaceous blades lacking hydathodes, and ovate to lanceolate, basifixed to peltate, denticulate blade scales, is described based on a single specimen from lowland Bolivia. This combination of characters suggests affinity to Elaphoglossum section Lepidoglossa , but precludes placement in any of the established subsections within that section.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 165–167.  相似文献   

4.
A new species, Linum vuralianum Yılmaz & Kaynak, is described and illustrated from west Anatolia, Turkey. It is closest to L. flavum L., but differs by its annual or biennial life form, the presence of rosette leaves at anthesis, and the absence of staminodes. The World Conservation Union (IUCN) threat category and observations on the population are noted. The geographical distribution of the new species and its related taxon is given.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 459–462.  相似文献   

5.
Macropora is a distinctive genus of anascan cheilostomes. All species have large zooids with an extensive cryptocystal frontal shield perforated by numerous pores through which parietal muscle strands pass. Also characteristic of Macropora are the calcified opercula closing the d -shaped orifice, avicularia resembling autozooids but having slightly enlarged, typically crenulated opercula/mandibles, and large ovicells that are often costate. This mostly Australasian genus has a documented fossil record stretching back to the Eocene. Here we revise the generic diagnosis of Macropora and describe eight new species from New Zealand (three Recent: M. nodulosa sp. nov. , M. filifera sp. nov. and M. carlosi sp. nov. ; five fossil: M. septispinosa sp. nov. , M. similis sp. nov. , M. pittensis sp. nov. , M. leeae sp. nov. and M. bullata sp. nov. ) and one new species from Japan ( M. mawatariorum sp. nov. ), the only species known with certainty to occur in the northern hemisphere. New observations are given for some previously described species, several of which are illustrated using SEM for the first time. The northern hemisphere Upper Cretaceous species Monoporella exsculpta (Marsson), showing features allowing it to be placed tentatively in the stem-group of Macropora , is redescribed. Attempts to resolve the phylogenetic relationships of species within Macropora were hampered by the relatively few morphological characters compared with the number of species, and it proved impossible to obtain a phylogeny robust to slight changes in taxon and/or character inclusion. The favoured cladogram has poor bootstrap and Bremer support, and its stratigraphical and biogeographical congruences are low.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 115–146.  相似文献   

6.
7.
Among the basal fern families, the Hymenophyllaceae, with more than 600 species, display a high diversity in terms of their morphology and the habitats that they occupy. We have chosen to focus on Trichomanes L., a clearly defined genus for which a phylogeny is presently being developed, to investigate the appearance of the climbing and epiphytic habits, as well as the related supposed adaptive characters. In this study we present the first review of the different ecological types within the genus: terrestrial, climbing (divided into hemi-epiphytic forms and true lianas), and epiphytic types. The study of several features concerning stem morphology and leaf size allows a proposal on relationships between ecology and plant morphology. Terrestrial species display a thick monocaulous rhizome with robust roots and short internodes. Climbing species are characterized by a branched, thick, creeping rhizome with long internodes. Epiphytic species also exhibit long, creeping and branching stems with long internodes but the rhizome is fine to filiform. Under these circumstances, there is a reduction of root system and frond size leading to dwarfism in numerous instances. This may be related to an extreme hygrophilous epiphytic strategy. Finally, hypotheses on the evolution of these habits and hence on the evolutionary relationships between ecology and characters are presented and discussed.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 142 , 41–63.  相似文献   

8.
Shell outlines of 202 extant cytheroidean ostracods were analysed in dorsal, lateral, and posterior views by elliptic Fourier analysis. The results obtained confirm that the exterior morphology is related to ecological factors as well as phylogenetic constraints. Phytal species living on tall seagrass and benthic species burrowing in sediments are characterized and differentiated from the species crawling on sediments by the presence of slender shells with tapered venters. With reference to reconstruction of ancestral state of outline traits on the molecular phylogeny, the hypothetical ancestor of cytheroidean ostracods is presumed to have had an average-shaped shell. Morphological plasticity of the shell outline was observed in many families. The phytal species living on tall seagrass appear to have evolved convergently with species from other habitats, acquiring slim shell outlines during the Cenozoic period. The present analysis also reveals the phylogenetic constraints on the morphological evolution of the Trachyleberididae in their adaptation to a burrowing habit.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 810–821.  相似文献   

9.
Although a wide variety of arthropods specialize on a specific host plant, little is known about the evolution of host–plant specialization in spiders. In several regions of South America, the Neotropical jumping spider Psecas chapoda associates with Bromelia balansae , a rosette-shaped plant that does not accumulate rain water in phytotelmata. We conducted experiments using bromeliad species with distinct architectures that were uncommon in the geographic range of P. chapoda to investigate the level of spider specialization in microhabitat structure. We also tested the influence of phytotelmata and foliar spines on host plant selection. B. balansae , Ananas comosus and Aechmea distichantha (tank-bromeliad), which share similar traits (e.g. long and narrow leaves), were colonized in similar frequencies. Aechmea fasciata , a tank-bromeliad that has short and broad leaves, was never colonized by these spiders, and Aechmea blanchetiana , tank-bromeliad with long and broad leaves, was only colonized infrequently. The removal of foliar spines did not affect the number of P. chapoda on B. balansae . Our findings suggest that microhabitat specialization by P. chapoda is based on rosette and leaf architectures. This unusual specialization likely evolved because the bromeliads with such architecture (i.e. B. balansae ) typically dominate the biogeographic area of P. chapoda , and because this microhabitat provides specific benefits to spiders, as shelter, and as foraging and reproductive sites.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 653–662.  相似文献   

10.
The species formerly recognized as Teucrium scorodonia in Madeira is here described as new: Teucrium francoi M. Seq., Capelo, J.C. Costa & R. Jardim. Morphologically close to species of Teucrium gr. scorodonia [ T. scorodonia L., T. pseudoscorodonia Desf., T. siculum (Raf.) Guss. and T. kotschyanum Poech], it exhibits, nonetheless, some distinct diagnostic characters. The indumentum density and type of hairs of T. francoi are clearly distinct from those of related species, as are the shape and dimensions of the leaves and bracts, calyx, and corolla, which are all taken as taxonomically significant diagnostic features. A diagnosis and a distribution map are presented for this new species. Morphology, ecology, biogeography, and conservation issues are discussed. Teucrium francoi , which is an endemic from Madeira (Portugal), is to be found mostly in the scope of the association Teucrio francoi–Origanetum virentis J.C. Costa, Capelo, Jardim, Sequeira, Lousã & Rivas-Martínez, but also occurs in somewhat humid habitats, such as open stands of Rosa mandonii Déségl. associated with small streams.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 639–647.  相似文献   

11.
The genus Killickia is described to accommodate the South African endemic species formerly placed in Micromeria sect. Hesperothymus . Morphological data, as well as results from unpublished phylogenetic studies support its separation from the genera Micromeria and Clinopodium . A new species Killickia lutea Bräuchler is described and three new combinations are made. Killickia is characterised as comprising solitary- or few-flowered cymes, a campanulate to subcampanulate (obconical) calyx with similar teeth, a corolla tube with two pubescent ridges and nutlets with scattered minute hairs. A thickened marginal vein in the leaves as typical for Micromeria is absent. As currently understood all species are restricted to the Drakensberg mountains and KwaZulu-Natal Midlands in eastern South Africa. A key to the species, brief notes on anatomy and ecology are provided.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 575–586.  相似文献   

12.
The optimal time for germination of a seed depends on environmental conditions of its habitat, the life cycle of the germinating plant, and the conditions for successful establishment, growing and reproduction. We studied the germination behaviour of the alpine annual Euphrasia minima and an alpine ecotype of E. salisburgensis in a lowland garden experiment. Seeds of both species and their hybrids germinated at constant (5 °C) and at varying temperatures (3–10 °C), and never before spring after seed ripening. Germination was spread over 3 years, which suggests that the seeds formed a persistent seed bank. The two species together with E. minima and E. minima hybrids differed significantly in the germination rate in the first and second spring.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 649–656.  相似文献   

13.
Tahina J.Dransf. & Rakotoarinivo, gen. nov. (Arecaceae) is described as a new genus from north-western Madagascar, with a single species T. spectabilis J.Dransf. & Rakotoarinivo, sp. nov. Tahina is included within tribe Chuniophoeniceae of subfamily Coryphoideae, based on the strictly tubular imbricate rachilla bracts, the flowers grouped in cincinni with tubular bracteoles, and the stalk-like base to the corolla. This position is corroborated by evidence from plastid DNA. Lamina anatomy is discussed in detail, and similarities with and differences from the other members of Chuniophoeniceae are discussed. Based on the ecological characteristics of the single locality, predictions are made on where else it may occur in Madagascar.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 79–91.  相似文献   

14.
The demographic dynamics of three populations of Dioon edule Lindl. (Zamiaceae) were studied in a fragmented landscape using projection matrix modelling. Compared with other plant species, D. edule behaves like a tree life-form species. Density and spatial distribution patterns varied among populations according to models for animal-dispersed tree species. In all scenarios, λ was most sensitive to changes in abundance of adult plants. The elasticity reproductive component (F) for the three populations was zero and stasis values (L) were higher, this being a function of the permanence of non-reproductive individuals. It was detected that disturbance influences the population dynamics of D. edule as a function of adult plant persistence. This observation suggests that the conservation of adult plants is critical for D. edule and perhaps for all cycads species. Adult plant decapitation should be halted at the 'Monte Oscuro' population, subjected to sustainable management since 1990, if higher seed production is needed in rural nurseries.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 381–391.  相似文献   

15.
This study highlights the morphological differences between two groups of plants; those that are recorded as hosts of the thrips Heliothrips haemorrhoidalis (Bouché) and those that remain free from infestation. Scanning electron microscope techniques were used to describe the morphology of the leaf surface of 19 species in order to help identify which morphological features could play a role in the selection of plant species by thrips from among a diverse botanical collection. H. haemorrhoidalis had a preference for species with leaves that were coriaceous, with one or both surfaces being smooth. Plants evading these thrips commonly possessed glandular trichomes. Thus morphology may have a role in deterring thrips from the leaf surface, as well as influencing the behaviour of predators that control thrips. Further detailed studies into the chemistry of leaves of hosts and nonhost species may help to further our understanding of selection mechanisms.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 109–130.  相似文献   

16.
17.
A new species of Veronica vadiniense in section Veronica is described from material from the Cantabrian Range, in the north-east of the province of León (north-west Spain). Several morphological characters related to stems, leaves, racemes, flowers and capsules are given, and also those related to the indumentum of different parts of the plant, especially calyx lobes and capsule. Indications about distribution and habitat with reference to bioclimatic, biogeographical and phytosociological aspects are provided. Diagnostic features are also given to enable comparison with the most similar species, Veronica officinalis and V. allionii , particularly in the indumentum and consistency of leaves, and in the indumentum and shape of the capsule.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 119–124.  相似文献   

18.
The resupinate leaves of 16 species of Alstroemeriaceae were examined using light- and scanning electron microscopy. The leaf anatomy is described for all of the species, that of the petiole and stem for selected species. The mesophyll consists of chlorenchyma and includes idioblasts that contain raphides. Dorsiventral, isolateral or isobilateral leaf types were observed. Petioles are always isolateral. Two epidermal types are commonly observed: type I contains jigsaw puzzle-like intercostal cells and longitudinally elongated cells above the veins; type II contains only longitudinally elongated cells, usually longer, above the veins. Some species have an epidermis which differs from the main types. All species show adaptation to resupination by having an inverted anatomy. Due to the twist of the leaves, adaxial indicates the lower surface and abaxial the upper. Stomata are found on both surfaces. Palisade cells, when they occur, are always on the abaxial surface. Most species are mesomorphic in spite of the dry environments in which they grow; a few show xeromorphic features. The leaves are compared and discussed with relation to ecological conditions.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 261−272.  相似文献   

19.
Aethionema rhodopaeum D. Pavlova is described as a new species from the eastern Rhodope Mountains. The plant was found growing only on serpentines, in two localities, at an altitude of approximately 400 m. The localities are typical open habitats with sparsely colonized debris. The plant communities, composed mainly of xerophytes with a mosaic distribution, contain a large number of rare and endemic species for the Bulgarian flora. The new species belongs to the Aethionema saxatile group and is quite close to the species A. saxatile (L.) R. Br., in particular to ssp. creticum and ssp. graecum . The following diagnostic features are given for the new species: inner filament length always greater than half the petal length, lack of teeth of the filaments, longer [2–3(3.5) mm] style than that of A. saxatile subspecies, and dark purple petals. All leaves are broadly elliptical to suborbicular, obtuse, and fleshy. The chromosome number of the new species is 2 n  = 24. The differences between the new species and related taxa are also discussed.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 533–540.  相似文献   

20.
Astragalus bahcesarayensis H. Akan, M. Fırat & M. Ekici (Leguminosae-Papilionoideae) from Turkey is described and illustrated. It is compared with A. dipsaceus Bunge and A. panduratus Bunge. The geographical distributions of the new species and related species are mapped.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 439–444.  相似文献   

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