摘要:

The pollen grain exine ofCentrolepis aristata(R.Br.) Boem. & Schultz. is like a quilt with top and bottom layers tied together at intervals with ring shaped fasteners, each having an open center (“scrobiculii”, Potonié 1934). Thus the top (tectum) extends down at intervals in the form of ring-shaped extensions providing continuity with the footlayer. In effect there are no columellae (bacules). The ectexine system is alveolate and much like the cap region of pollen ofPinus.

ISSN:0017-3134    

DOI:10.1080/00173139609430495

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Pollen characters of Canary Resedaceae with special reference to endemic taxa

ISSN:0017-3134    

DOI:10.1080/00173139609430496

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The pollen morphology of the 16 recognized species of the genusAsphodelusL. (Asphodelaceae) has been investigated by light and scanning electron microscopy. Four pollen types can be distinguished on the basis of variation in size of the polar, equatorial longitudinal and transverse axes, as well as in exine structure and sculpturing, which correlate with the subdivision of the genus into sections. Correlations between pollen size and some biological characters are made. Phylogenetic implications are suggested, and trends of pollen evolution in the genus are indicated.

ISSN:0017-3134    

DOI:10.1080/00173139609430497

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A detailed investigation of Holocene sediments of various facies has revealed some regularities in the distribution of redeposited pollen for various periods of the Holocene. The greatest amount of redeposited pollen is observed in the boreal and sub-boreal sediments of the Black Sea shelf. Smaller quantities of redeposited pollen are found in the abyssal parts of the sea and in alluvial formations. Single taxa are noticeable in Holocene peat bogs and lakes of the Colchis lowland, in the lowlands of East Georgia. Redeposition is scarcely noticeable in lagoons, buried soils, raised bogs and zoogenic formations. It is necessary to distinguish between primary and redeposited pollen in order to avoid mistakes when reconstructing vegetation of the past epochs in mountainous regions.

ISSN:0017-3134    

DOI:10.1080/00173139609430498

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A study was made of the total pollen production per individual tree in ten anemophilous arboreal species (including wild, cultivated and ornamental species) of considerable aerobiological importance:Pinus pinaster, Ulmus minor, Juglans regia, Platanus hispanica, Quercus rotundifolia, Salix atrocinerea, Populus nigra, Acer negundo, Olea europaea and Fraxinus angustifolia.

ISSN:0017-3134    

DOI:10.1080/00173139609430499

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An improved procedure for preparing a pollen concentrate from clayey sediments is presented. Two new steps have been added compared with earlier procedures. Firstly an initial dispersion which enhances the pollen yield from a sample so that a smaller amount of material is required for the separation, and secondly, the use of CsCl for sequential density separation which results in high purity pollen concentrates. Our separation technique was tested through radiocarbon dating a sediment sequence from Old Uppsala, central Sweden.

ISSN:0017-3134    

DOI:10.1080/00173139609430500

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Maurice Reille. Pollen et Spores d'Europe et d'Afrique du Nord. 1992. 522 pp. ISBN 2–9507175–0–0. Price: 1600 FF. Supplement 1.332 pp. 1995. ISBN 2–9507175–1–9. Price: 800 FF. Reviewed by Siwert Nilsson.

ISSN:0017-3134    

DOI:10.1080/00173139609430501

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial board page(s) for this issue

ISSN:0017-3134    

DOI:10.1080/00173139609430494

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor