| Abstract: |
SUMMARYIn the present work, the pollen morphology of fifty-three of caryophyllaceous taxa which represent twenty genera, forty-five species, seven subspecies and one variety were examined using both the Light Microscope (LM) and the Scanning Electron Microscope Cumulative tables and plates were considered to various discussion and conclusions to facilitate the description of most taxonomic and phylogenetic significance. And thus an artificial key has been constructed based on pollen morphology to differentiate bThe general conclusions are summarized in the following points:1- The variation in the aperture numbers, pollen diameters and pollen shapes represents useful criteria in taxonomic treatment among the studied taxa.2- The investigation using LM revealed variation in the length of columellae, which are either uniform in length or longer towards the mesoporium and shorter towards the pori.3- The tectum variations are of taxonomic significance which ranging between imperforate, microperforate, perforate, foveolate and foveolate-reticulate.4- The sculpturing patterns as seen by SEM are considered to be of major significance as diagnostic attributes between the studied taxa.5- In the present work, the operculum and their granules in addition to the annulus provide additional clue for the separation of some taxa.6- The numerical analysis and evolutionary trends of pollen grains characters indicate highly similarity and highly significance in identification and classification of the studied taxa.7- The evolutionary trends of the studied taxa obtained from pollen morphology depending on four lines: apertures shape, apertures number, tectum porforation and sculpture patterns. Comparison of evolutionary trends of the different types of selected four8- The data obtained refers to a degree of advancement in the pollen criteria;a) The members of the tricolpate which includes Minuartia geniculata, Sphaerocoma hookeri, the three genera of tribe Polycarpeae, and Telephium imperati ssp. imperati have lowest graded and occupied the primitive position.b) Silene succulenta and S. gallica var. quenquevulnera occupied the advanced position among the studied taxa.9- The studied taxa are divided into two main groups. The first 11 taxa are isopoler and tricolpate, the other includes 42 taxa with apolar and polypantoporate, this result refers to a marked heterogeneity.10- Except for Minuartia geniculata with isopolar and tricolpate pollen grains, the other studied taxa of Minuartia: M. hybrida and M. verna are with their pollen grains apolar and polypantoporate. In the present work may strongly support the use of the s11- According to the similarity in pollen attributes of Telephium with other genera of tribe Polycarpeae might be reinforced the position of Telephium in Caryophyllaceae.12- In the present work, the diagnostic characters to tribe Paronycheae support the suggestion of placement of this group in a special subfamily intermediate between the tricolpate and polypantoporate types.
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