Taxonomic Studies of North African Caryophyllaceae with Special Reference to the Flora of Libya

Botany

Abuhadra, Mohamed Nuri

University:University of Glasgow

关键词: Botany;   

Others  :  http://theses.gla.ac.uk/74899/1/11007819.pdf

来源: University of Glasgow

【 摘 要 】

The thesis deals with the Caryophyllaceae, a family well represented in the countries of North Africa including Libya which has about 22 genera and 80 species within the three subfamilies as currently recognised. The principal part of the thesis concerns the description of the seeds of the Libyan species primarily with the use of scanning electron microscope (SEM). SEM produces very revealing images of the testa cells and their often striking ornamentaion. These seed characters as well as seed colour, shape and size, hilum position and radicle shape have been applied to particular problems at several taxonomic levels up to that of the subfamilies, the limits of which have long been controversial. Within the Caryophyllaceae, whatever its scope, seed characters have always been given importance but that importance is often under-rated. A survey of the calcium oxalate crystals in the genera Arenaria, Minuartia and Moehringia has been undertaken to an extent and in a detail not previously carried out within any large genus of the family. The size, type and distribution of the foliar crystals has taxonomic significance particularly at the sectional and series. There are especially large crystals in Minuartia subgenus Minuartia which appear to be of taxonomic importance. The micromorphology of the capsular walls of Silene and a few other genera has been investigated and has taxonomic importance but the results are not discussed in detail. Presented as appendices, there are keys for the identification of the seeds of Libyan Caryophyllaceae, for fruiting material of Libyan Silene as well as for the infrageneric taxa of Arenaria, Minuartia and Moehringia based on crystals.