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1.
The wood anatomy ofPhragmotheca (Bombacaceae) is described based on three species and three specimens. The wood features ofPhragmotheca, Matisia, andQuararibea are very similar and differ only in the size of the intervascular pits and vessel diameters. Based on wood anatomical characteristics, these three genera form a distinct and homogeneous group within both the tribe Quararibeae and the family Bombacaceae.  相似文献   

2.
A wood anatomical study of the Mexican species ofTapirira was undertaken to uncover evidence to help clarify the systematics of the genus. Three to five individuals of each of 10 populations from throughout the range of the genus in Mexico were studied. For comparative purposes, three Central and South American species were also examined. Cluster analysis showed that the genus in Mexico can be separated into two phenetic units, represented byT. mexicana, a species widely distributed in Mexico, andT. chimalapana, a species endemic to the Isthmus of Tehuantepec. Canonical discriminant and factor analyses indicate that the quantitative wood characters most useful in distinguishing these species are wall thickness of fibers and vessels, diameter of fiber lumen, and diameter and frequency of radial canals. These species also differ in presence/absence of tannins in the fibers and color and specific gravity of the wood. The South American species,Tapirira bethanniana, T. guianensis, andT. obtusa, have wood anatomy similar to that ofT. chimalapana. The differences in the wood anatomical characters betweenT. mexicana and the other taxa suggest that the infrageneric classification ofTapirira should be reevaluated. The results of this study support the utility of sampling of populations in comparative wood anatomy.  相似文献   

3.
David A. Young 《Brittonia》1978,30(4):411-415
Species ofRhus subgen.Lobadium have in the past been grouped into five sections:Pseudosumac, Stypkonia,Pseudoschmaltzia, Rhoeidium andLobadium. Reexamination of the morphological criteria used to delimit the sections, as well as consideration of data from flavonoid chemistry and wood anatomy, suggest that the affinities of this group of taxa are best reflected by recognizing three sections and three subsections. The namesPseudosumac andPseudoschmaltzia are rejected as beingnomina nuda.  相似文献   

4.
A fungus known asCytosphaera mangiferae Died, was isolated for the first time from the diseased tissues of standing trees ofAquilaria agallocha Roxb. Irregular patches of diseased wood, a result of natural infection, are found in the trunks of standingA. agallocha trees, which are of great economic importance. A fragrant perfume locally known as ‘attar’ is obtained from the diseased wood by steam distillation. Incomplete or partially diseased wood is employed in the preparation of a joss-stick locally known as ‘agarbatee,’ which gives out fragrant fumes on burning. The fungus colonised wood blocks of A agallocha when these were inoculated artificially. There is a possibility of commercial exploitation for the production of diseased wood by artificial infection.  相似文献   

5.
6.
It has been found thatTrichogramma semblidis (Aurv.) parasitizes the eggs ofleperisinus fraxini (Panz.),L. orni (Fuchs) andHylesinus crenatus (Fabr.) in typical variant ofCircaeo-Alnetum Oberdorfer 1953 in the Laski Experimental Forestry near Kepno. Thorough studies were conducted on exposed European ash logs and split wood in 3 methodical variants. The analysis of the galleries ofLeperisinus fraxini has showed that the average egg infestation amounted to 14.1%, 13.0% and 11.1% respectively. The egg infestation of individual gallery systems in the exposed control logs and split wood ranged between 2.7–51.2%, 1.2–44.1% and 1.7–69.2%, respectively, in different variants and the average effectiveness of the parasite amounted to 12.7% of the host egg mortality in 1970. Earlier observations and analyses of the gallery systems made on the ash trunks and branches in 1967 and 1968 showed 80.0% and 98.0% infestation of the eggs ofL. fraxini and 10.0% and 1.5% infestation of the eggs ofL. orni. Separate developmental stages of the parasite, the behaviour of the latter and penetration of the gallery systems were observed too. The most important data on the host species ofT. semblidis have been compared.  相似文献   

7.
A combined taxonomic revision and wood anatomical study ofDicorynia, a South American genus of legumes that is unusual in both its floral and wood anatomy, is presented. Two possible evolutionary pathways leading to the unique 8-to 10-thecate anthers are discussed, and it is concluded that apical proliferation of the thecal primordia is the more likely. Gross and microscopic features of this silica-accumulating wood are given in detail and contrasted with other legume woods especially those containing silica. Economic uses of the trees, especially the wood ofD. guianensis, are discussed particularly in regard to marine construction. It is suggested that the high resistance of this wood to marine borers lies not so much in its silica content as to the presence of some other chemical. Based on the similarity of floral and fruit structures, the number of species is reduced from 7 to 2:D. guianensis in the Guianas andD. paraensis in the Amazonian region. Vegetative variations in the Amazonian population, previously given species rank, are reduced to 5 new varieties ofD. paraensis.  相似文献   

8.
Asteropeia andPhysena are both enigmatic woody dicotyledons from Madagascar. Various taxonomic affinities have been suggested for both genera, but no consensus has been reached. An analysis of rbcL sequence data strongly supports recognition of the sister-group relationship ofAsteropeia andPhysena and their placement as the sister group to Caryophyllales. Many similarities were noted betweenAsteropeia andPhysena for stem, wood, leaf, flower, pollen, and fruit characters. The most notable differences are found in the morphology of the flowers and the anatomy of the wood rays.  相似文献   

9.
A new genusBactrodesmiastrum Hol.-Jech. is established for a fungus of dematiaceous hyphomycetes collected on decaying wood ofFagus sylvatica in Czechoslovakia. The only species,B. obscurum Hol.-Jech. is described and illustrated.  相似文献   

10.
The width of the increment zones in the xylem of Swietenia macrophylla King and Cedrela odorata L. was investigated by dendroecological methods in a primary forest near Aripuanã, Mato Grosso, Brazil (10°09′S, 59°26′W). The annual period of cambial cell division and its intra-annual variation were determined by dendrometer measurements of 30 trees of each species. Tree-ring width chronologies for Swietenia and Cedrela were developed from cross-dated increment curves of 33 out of 47 Swietenia and 51 out of 64 Cedrela trees. Simple correlations were computed between the radial growth increment and monthly precipitation for the period 1890–2000. In Swietenia, cambium activity occurred throughout almost the whole year, but in Cedrela it was restricted to the rainy period from September of the previous year to June of the current year. Tree-rings were formed annually in the juvenile and adult wood of Cedrela, while in Swietenia the annual formation of tree-rings was restricted to the adult wood. Consequently the age of the Swietenia trees could be dated by the tree-rings in good approximation, while age dating of the Cedrela trees was exact. Correlation analyses revealed a significant relationship between the precipitation at the beginning and at the end of the growth season and the width of the increment zones in the adult xylem of Swietenia. In contrast, the width of the growth increment in the xylem of Cedrela was significantly correlated with the precipitation in March and May of the previous growth period.  相似文献   

11.
12.
Comparison of the ontogenies of bivalves of different habitats and systematic position provide two main conclusions. The first is that bivalves stick to a certain basic program of ontogeny which can be divided into six phases. The first three phases are parallel to those of some other invertebrates, the 4th phase is parallel to that of conchiferan molluscs, with, the 5th phase, bivalve characters are acquired, and in the 6th phase, genus-specific adult organization is reached. The second is that within this basic developmental programm specific differences occur. The ontogeny ofTeredora is similar to that of many marine bivalves and is characterized by a strong plasticity. The adult, in contrast, is highly specialized for living within wood. InAnodonta, the opposite is true and embryonic development even includes a parasitic stage, while the adult is of a more general organization. Due to brood-protection and embryonic nursing, the whole organogenesis ofSphaerium becomes directed towards adult organization. Ontogenetic development of a general body plan of the Bivalvia provides a model for the evolution of the first bivalves (protobranchs excluded) from univalves by a one-step alteration connected with shell mineralization and loss of the buccal mass affecting the embryo near end of embryogenesis.  相似文献   

13.
Four collections of three species ofTrimenia and one collection ofPiptocalyx were studied; early-formed and later-formed wood was analyzed for oneTrimenia. Liquid-preserved material permitted analysis of mucilage and starch storage in wood ofT. neocaledonica andP. moorei. BecausePiptocalyx is scandent whereasTrimenia is arborescent, wood differences relative to evolution of a climbing habit could be examined.Piptocalyx contrasts withTrimenia in having wider vessels, more numerous per mm2, resulting in a conductive area five times greater per unit area than that of theTrimenia woods averaged.Piptocalyx has appreciably fewer bars per perforation plate and thus much greater conductive area per perforation plate than have the species ofTrimenia. Rays inPiptocalyx are much taller and wider than those ofTrimenia. Wood ofTrimeniaceae is highly primitive in its scalariform perforation plates, scalariform lateral wall pitting on vessels, relatively long vessels elements, and heterocellular rays. Imperforate tracheary elements are septate nucleate fibertracheids (or even libriform fibers) rather than tracheids, but loss of borders on pits (and thus lowered conductive function of the imperforate tracheary elements) can be explained by the development of these elements into starchstoring cells. Some fiber-tracheids inT. neocaledonica are enlarged mucilagecontaining cells. Details of vessel structure inTrimeniaceae are similar to those ofMonimiaceae (s. s.), but similarity to some other lauralean (annonalean) families may be found: in mucilage presence,Trimeniaceae resembleLauraceae rather thanMonimiaceae. Wood ofTrimeniaceae may be regarded as highly mesomorphic, corresponding to the moist habitats in which all of the species occur.  相似文献   

14.
An examination of the external morphology of a recent collection from Araracuara, Colombia, has suggested that the plant belongs to the primarily Old World family Dipterocarpaceae. A study of the wood, bark, and pith anatomy of this new taxon,Pseudomonotes tropenbosii Londoño, Alvarez & Forero, was undertaken to help confirm its systematic affinities. Comparisons ofPseudomonotes with data from the literature and reference wood slides, coupled with the use of computer-aided identification keys, support the view that its closest relationships probably are within the family Dipterocarpaceae. Detailed anatomical comparisons have revealed thatPseudomonotes' relationships are most likely to be with the subfamily Monotoideae, comprised of the African generaMonotes A. DC. andMarquesia Gilg.  相似文献   

15.
Growth responses ofCasuarina cunninghamiana to inoculation withFrankia are described in unsterilized field soils at three sites. At Mt Crawford, South Australia, seedlings of three provenances ofC. cunninghamiana were inoculated with a singleFrankia source just prior to planting out. Forty-four months after planting, inoculation had more than doubled wood production by twoC. cunninghamiana provenances, whilst a third provenance grew poorly and did not respond to inoculation. In Zimbabwe, seedlings of one provenance ofC. cunninghamiana were inoculated in the nursery with one of four differentFrankia strains. In an N deficient soil at Kadoma, three of theseFrankia increased tree height 14 months after planting by between 50% and 70% in comparison to the uninoculated seedlings. The fourthFrankia strain resulted in increased tree height to three times that of the uninoculated controls and up to double that of the other threeFrankia strains. At Gympie, Queensland, Australia, seedlings ofC. cunninghamiana raised open-rooted in a nursery bed were inoculated withFrankia seventeen weeks before planting out. During the 22 months following planting in the field, tree growth was limited by soil P status and there was no response in tree height or stem diameter to inoculation withFrankia or to N fertilizer unless P was applied. In the presence of added P there was a significant response both toFrankia inoculation and to N fertilizer. This positive interaction between P application and N treatment was reflected in wood volumes-inoculated trees and those trees supplied N fertilizer produced 34% and 95% more wood volume than did the uninoculated trees. These results demonstrate the potential to increase the productivity of Casuarina plantings by inoculation withFrankia and by alleviation of P deficiency.  相似文献   

16.
The wood and bark anatomy of all three species of Hypocalyptus from the monotypic South African endemic tribe Hypocalypteae were studied. Despite large morphological differences (especially in habit) the species were found to be similar in wood and bark structure. Discontinuities are quantitative only, relating mainly to differences in growth form between H. oxalidifolius, a short-lived shrublet, and the two other species, H. coluteoides and H. sophoroides, both of which are erect shrubs or small trees of up to 6 m tall. Hypocalyptus wood has a mesomorphic structure with vessels solitary or in small groups, reflecting relatively moist habitats in fynbos vegetation. In contrast to many genera of Leguminosae for which data are available, crystals are absent from the wood. This is the first report of tanniniferous tubes in the wood of Leguminosae (previously reported only in Myristicaceae and a genus from Ulmaceae). The presence of tanniniferous tubes and the absence of crystals in all three species of Hypocalyptus underline the isolated position of the genus and support its tribal status.  相似文献   

17.
A new species ofAnuretes collected from the gills ofDiagramma crassispinum Day at Cape Comorin, India, is described in detail. The carapace of the three females obtained was folded ventrally likeHermilius on the gill filaments.  相似文献   

18.
Decay resistance of Rubber wood (Hevea brasiliensis) esterified with three fatty acid chlorides (hexanoyl chloride (C6), decanoyl chloride (C10) and tetra-decanoyl chloride (C14)) was evaluated. Unmodified and modified wood samples were exposed to a brown rot (Polyporus meliae) and a white rot (Coriolus versicolor) fungus for 12 weeks. Unmodified rubber wood was severely decayed by P. meliae and C. versicolor, which was indicated by significant weight loss. The rate of decay by brown rot was higher than white rot. Modified wood samples exhibited very good resistant to brown and white-rot fungi. The degree of protection increased with increase in degree of modification. P. meliae, a brown rot fungus, removed structural carbohydrate component in unmodified wood selectively whereas, C. vesicolor showed preference to lignin. The FTIR spectra of modified wood exposed to fungi show no significant changes in relative peak intensities of lignin/carbohydrates indicating effectiveness of chemically modified wood in restricting chemical degradation. Chemical modification occurred more efficiently at carbohydrate portion of the wood. Therefore, it is more effective in retarding decay due to P. meliae.  相似文献   

19.
The course of resin canals in stem cortex and the continuity between resin canals in leaves and those in stem cortex were investigated. The present paper is the first of three parts of the investigation. In this paper, fundamental features of resin canals and actual resin canal patterns in the Taxaceae, Cephalotaxaceae and Podocarpaceae are reported. From the observation of serial transections of shoots, composite diagrams and three-dimensional models of resin canal patterns are drawn. Central canals, if present, run vertically in stem cortex and sometimes divide, end blindly or unite each other. The distance between two adjacent central canals fluctuates rhythmically in connection with the vascular supply from the stem to leaves. The resin canal patterns of the families are classified into four types. Those ofTaxus, Nothotaxus and three species ofDacrydium belong to the Taxus type, those ofTorreya andCephalotaxus to the Torreya type, those ofDacrydium elatum, Podocarpus alpinus, P. elatus, P. elongatus andP. neriifolius to the Dacrydium type, those ofP. macrophyllus, P. nagi andP. koordersii to the Podocarpus type.  相似文献   

20.
It is suggested that communities of cultivated forests can be incorporated into the system of “natural” wood communities either as facies, variants or subassociations, if they differ below the association level; if they differ on the association level, a new association is suggested, with the prefix “culti-” before the planted dominant tree species. Most of our planted forest communities differ on the level of association or less; the communities ofRobinia are the exception. The authors agree withJurko (1963) in classifying them as individual associations, alliances, order and class.  相似文献   

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