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1.
The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.  相似文献   

2.
Recently, results of a 3-year study showed the importance of abiotic factors such as water temperature, stream discharge and the hyporheic zone on the behaviour, performance and loss of the residual dosages (amount of the injected dosage left at each station) of two commercial liquid formulations of Bacillus thuringiensis subsp. israelensis ( Bti ), Teknar HP-D and Vectobac 1200L. Experiments were performed in the same stream and under environmental conditions that allowed comparisons of results between formulations. To improve our understanding of the influence of abiotic factors on the behaviour and the performance of these formulations, a 2-year experiment using the same products was conducted in another river characterized by a much different profile, higher discharges and colder temperatures. A field procedure based on a system of gutters located on the bank of the river already used in the previous 3-year experiment was utilized. Black fly larval mortalities were recorded along the river at different distances (stations) to evaluate the behaviour and the performance of the products while water samples taken at the stations were tested in the laboratory against mosquito neonate larvae to evaluate the residual dosages of Bti at each station. Results showed that higher residual dosages of the Vectobac 1200L were recovered compared to Teknar HP-D along the river. Although higher dosages were recovered, higher mortality was observed only for the Vectobac 1200 L in high discharge conditions. As seen before, the hyporheic zone (interstitial water between the streambed and groundwater) produced a major loss of the dosages in the first meters of the river. But because of the river profile, the hyporheic zone had a lesser effect on the loss of the dosages further in the river resulting in very long carries for both Teknar HP-D and Vectobac 1200L.  相似文献   

3.
(1) In this paper, differences among the five genera constituting the tribe Cimi cifugeae of the family Ranunculaceae are discussed. Beesia, the first genus, with compound cymes and flowers bearing neither petals nor staminodes, is different from the other four genera with simple or compound racemes and flowers bearing either petals or staminodes, and may occupy a primitive position within the tribe. As to the other four genera, Souliea is characterized by the stem without basal leaf but with 2~5 sheath-like cataphylls, the sepals being deciduous but not caducous, moderate in size and petaloid, the petals being much smaller than sepals, but pink in color and more or less petaloid, the pollen grains being pan tocolpate or pantoporate, the carpels being 1~3 per flower, when mature forming dry linear follicles conspicuously reticulate on the surface and dehiscent along the ventral suture, and the seeds being reticulate-foveolate on the surface. These diagnostic characters indicate clear ly that Souliea might have deviated from the lineage formed by the next three genera, i. e. Anemopsis, Cimicifuga, and Actaea, which have their own well-recognizable diagnostic characters. Anemopsis is characterized by the normally developed basal leaf, the racemose inflorescence with sparse and few long pedicellate flowers, the sepals 7~10 in number, mod erate in size, and petaloid, the petals slightly smaller than sepals, the tricolpate pollen grains, the carpels 2~4 per flower, stalked, when mature forming dry oblong follicles with transverse veins on the surface, and the seeds with scaly membranous wings. Cimicifuga is distinguished by the normally developed basal leaf, the caducous, small, often sepaloid sepa ls, the organs of the second floral whorl sometimes with empty sterile anthers being stamin odes not petals, the tricolpate pollen grains, the carpels 1~8 per flower, when mature form ing dry oblong or ovoid follicles with transverse veins on the surface, and the seeds usually with scaly membranous wings. The last genus Actaea is different by the basal leaf trans formed into a small scale, the caducous, small, often sepaloid sepals, the organs of the sec ond floral whorl being clawed petals, the pollen grains with 3(4~6) colpi, carpel 1 per flow er, when mature forming a fleshy indehiscent berry smooth on the surface and without any veins, the seeds roughish or slightly rugose, neither foveolate nor winged on the surface, and the advanced most asymmetric karyotype. According to the diagnostic characters given above, we believe that Beesia, Souliea, Anemopsis, Cimicifuga, and Actaea do represent five independent genera, and the treatment of the tribe Cimicifugeae including these five genera in it by Hutchinson (1923), Janchen (1949) and some other authors, has precisely shown the taxonomic diversity within the tribe. We are therefore unable to accept the treatment published by Compton et al. (1998) to lump the two genera, Souliea and Cimicifuga, into the genus Actaea. (2) Compton et al. (1998, 1997) found out that the Chinese plants previously identified by various authors as Cimicifuga foetida L., in which the terminal and lateral racemes of the compound raceme flower more or less simultaneously, differ from the true C. foetida L. in northern Asia, in which the terminal raceme of the compound raceme flowers before the lateral ones, and thus restored the species name Cimicifuga mairei Lévl. , which was formerly reduced to the synonymy of C. foetida L. , for the Chinese plants. After examining the specimens collected from Siberia and from Southwest China we failed to find out any other differences in both vegetative and reproductive organs between the plants of the two regions, and we consider that it is better to treat the populations in Southwest and Central China as a geographical variety of Cimicifuga foetida L. A new combination, Cimicifuga foetida L. var. mairei (Lévl.) W. T. Wang & Zh. Wang, is thus made. (3) 3 species of Delphinium, 1 species and 1 variety of Clematis are described as new.  相似文献   

4.
The present study describes the fetal regions ethmoidalis and orbitotemporalis of the cranium of Galea musteloides and Kerodon rupestris and compares them with Galea spixii and Cavia porcellus . The fetal crania of these representatives of the Caviinae were serially sectioned and 3D plate reconstructions were built. For a broader scope, serially sectioned heads of the caviomorph taxa Hydrochaeris hydrochaeris and Dasyprocta leporina were also examined. The ethmoidal and orbitotemporal regions of the cranium provides characters that are pertinent to the discussion of systematics of the Caviinae. Nine cranial characters were identified as being significant and discussed phylogenetically. Taking the monophyly of the Cavioidea as given, two characters are autapomorphic for the genus Galea: the reduction of the crista semicircularis and the lacrimale forming the 'arco antorbitario' (Kraglievich 1930). Cavia is the sister group of Galea; synapomorphic characters are the extent of the processus palatinus medialis of the praemaxillare and the presence lamina pterygoidea of the alisphenoid. There were no apomorphic characters of the structural complexes examined that could support the Caviinae. The reduced and nonperforated alisphenoid is an autapomorphic feature of the Caviidae. The division of the nasoturbinale is evidence for a sistergroup relationship of the Hydrochaeridae and the Caviidae. Autapomorphic characters for the Cavioidea include the ventrolateral opening of the organon vomeronasale and the lateral prolongation of the lacrimale.  相似文献   

5.
The meadows of the floodplains of the Saône and the Meuse contain similar ecosystems subject to regular winter and spring flooding. The floristic and faunistic biodiversity decreases with the intensification of agricultural practices. The plant communities show the same zonation along a topographic gradient and have similar floristic progression. Thus, the climatic, biogeographic, human and soil factors have determined the floristic particularities of each valley. The floristic affinities of the two floodplains permitted the comparison of the phenological development of fourteen plant species. Many gaps in the development of species have been observed. These could be explained by the climatic differences betwen the two valleys (sub-Mediterranean influences in the Saône and sub-Atlantic in the Meuse), the existence of different types of soils in each valley (sand part more important in the Saône) and the occurrence of specific ecotypes in each valley.  相似文献   

6.
The foraging behaviour of Encarsia formosa was analyzed using a stochastic simulation model of the parasitoid's behaviour. Parasitoids were allowed to search during a day on a tomato plant infested with immatures of the greenhouse whitefly, Trialeurodes vaporariorum. The model simulates searching, host selection, host handling and patch leaving behaviour, and the physiological state of the parasitoid. The outputs of the model are the number of visited leaflets and the number of hosts encountered, parasitized or killed by host feeding. The simulation results agreed well with observations of parasitoids foraging on tomato plants. The number of encounters and ovipositions on the plant increased with host density according to a type II functional response. At a clustered host distribution over leaflets and low host densities, the most important parameters affecting the number of ovipositions were the leaf area, the parasitoid's walking speed and walking activity, the probability of oviposition after encountering a host, the initial egg load and the ratio of search times on both leaf sides. At high densities, the maximum egg load and the giving-up time on a leaflet since latest host encounter were the most essential parameters.  相似文献   

7.
A narrow relation has been hold between the beginnings of the metallurgy and social hierarchical structuring, in the sense of breaking with previous social organizations, has been discussed in this paper from the data obtained by the anthropomorphous drawings. From the ancient megaliths, the human figures were described with instruments that provide power and individuality. This fact, joined to the evidence of grave goods with prestige elements, propose the beginning of the hierarchy in the own social evolution of the production society, constituting the megalithic culture and his drawings the trustworthy expression of this hypothesis.  相似文献   

8.
A stratigraphical chart of marine ostracoda from Lower Miocene to Recent is established. Selected species (approximatively 220) are those morphologicaly well characterized and known from different parts of the Mediterranean area. It appears that: • lower Miocene ostracodes are still poorly known; • specific diversity is high during the Tortonian and the Lower Messinian before the complete disappearance of marine Mediterranean species during the Upper Messinian évaporitic episodes; • during the early Pliocene, about half of the Upper Miocene marine species are reintroduced with the Atlantic waters; other species migrate for the first time in the Mediterranean Sea by the same way; • at the end of the Pliocene or at the beginning of the Pleistocene several species known in Mediterranean since the Middle Miocene or before, such as Cytherella sp. gr. transversa and Ruggieria tetraptera, as well some “nordic guests” such as Hemicythere villosa and Cythere lutea, appear. This work is an opportunity to confirme a Late Miocene age for the Neogene of Skyros (Aegean Sea), to assign the “Upper Pliocene” of Terquem to the Lower Pleistocene and to refute the existence of a pliocene psychrosphere.  相似文献   

9.
The studies and the researches carried out in the last years on the Palaeolithic site of Isernia La Pineta have brought to consider in new way the activities realized by the human group that lived the basin of Isernia during the Middle Pleistocene offering an important key of interpretation of the behavioural strategies of the prehistoric man. The analysis of the exploitation of the raw material has confirmed the presence on the site of two different lithotypes: flint and limestone; the lithological dichotomy is related to the functional dichotomy of the raw material that seems to have conditioned the activities of the human group in different areas of the site. The necessity to deepen the study on the limestone has derived from the evidence brought to light in the last excavation campaigns of a remarkable concentration of the flaked limestone pebbles and the flake scars in some areas of the explored archeosurfaces, particularly on the 3a and on the overlooking layers. The present study has the purpose to explain the characteristics of the limestone finds both in reference to the raw material and to its state of preservation both to the technotypological evidences and its spatial distribution with the purpose to better understand the modalities of the exploitation of the raw material. The information collected until today have permitted to obtain a precise knowledge of the environmental context and the territorial resources exploited by the human group showing an opportunistic capability to find the most advantageous behavioural solution for the necessities of subsistence.  相似文献   

10.
The social impact of the mahogany trade on the indigenous peoples of Brazil is described. Emphasis is placed on the violence directed against Indians and the consequences of the destruction of their environment which results from the trade. Also mentioned are the judicial issues regarding the illegal extraction of mahogany from protected areas and several of the court cases against logging companies. A moratorium on mahogany logging in Brazil is advocated as is the right of indigenous peoples to control their lands and resources as the way to conserve their environment.  相似文献   

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