Hedberg, Prof. Olovkelbessa, Ensermu2021-12-132023-11-082021-12-132023-11-081982-06http://etd.aau.edu.et/handle/123456789/29260The pollen morphology of ni neteen s pec i es of Acanthaceae : nine of A5ystneia and ten of five other genera ha ve been inves tigated usinG l i ght and/or electron mic roscope s . The five gener a Gr a p tophyllurn , Jacobini a, Jus t i c i a , Mackays and ~~~ cun be sepa r ated fr om each other by the number and characte r of a pertur es , exine st r at ifi cat i on and/or by the natur e of the " trem" a r ea". The study has r evealed tha t the pollen gr ains of the ge nus H6yst ns i a a r e th r ee - pora te and the surfa ces a r e provi ded with nine colpoid streaks . The sexine i s smooth. The spec i es can be separ ated from each other by the di ffe rence i n the pr omine nce of the colpoi d s treaks and by the nature of t he sexi nUQue region a r ound the por e . A detailed study of the pa n- t r opi c al spec i es ~ . gangetica (L . ) T. hnders . has r esulted in its s ubdivis i on into two geogr aphic a l s ubspec i es on the basi s of corolla and s tyle and s t i gma l engths . It i s also s uppor ted by poll en s i ze and seed morphol ogy . The subspec i es with long coroll a a nd s tyle and s tigma i s desi gna t ed as subs p . gpnget ica and the one with shor t corol la and style and sti gma 6ubsp . mic r antha . The distribution of both taxa i s i llustr ated .enA Palynological- TaXon0mic Study Of the Ge:nusThesis