Inventory And Diversity Of Vascular Plants In Mt.Kenya,East Africa

Mt.Kenya is the highest mountain of Kenya and the second one in Africa,it has rich plant diversity.At present,we get The Checklist of Vascular Plants from Mt Kenya,East Africa which contains most of the plant species in this area up to now,through literature reviewing,specimens checking,specimens collection and identification,and we get the following conclusions:1)Totally,there are 1496 indigenous vascular plants(697 genera,156 families)in Mt.Kenya,in which,there are 9 lycophytes(5 genera,2 families),131 ferns(55 genera,20 families),3 gymnosperms(3 genera,2 families)and 1353 angiosperms(634 genera,132 families).Aspleniaceae(27 speices),Dryopteridaceae(23 species)and Pteridaceae(21 species)are the three biggest families and Asplenum(27 species),Dryopteris(9 species),Elaphoglossum(8 species)and Pteris(7 species)are the four biggest genera in lower vascular plants(lycophytes and ferns).There are six families which coutains more than 50 species in seed plants,they are Asteraceae(155 species),Poaceae(123 species),Fabaceae(96 species),Cyperaceae(75 species),Lamiaceae(60 species),Orchidaceae(59 species)and Rubiaceae(58 species).The three biggest genera in seed plants are Cyperus(26 species),Helychrisum(22 species)and Crotalaria(20 species).2)Mt.Kenya plays an important role for the flora of Kenya.There are over 60%ferns and only 22.48%angiosperms of Kenya are found in Mt.Kenya.Some big families and genra have high proportion of Kenyan flora,such as Dryopteridaceae(71.88%),Asteraceae(38.46%),Lamiaceae(29.13%),Cyperzus(100%),Helychrisum(91.67%),Galium(90.91%),Dryopteris(81.82%),Elaphoglossum(80.00%)and Alchemilla(76.92%).It can be said that,some families and genera of plants from Mt.Kenya are also important parts of the world flora,such as Aspleniaceae(3.70%),Conyza(16.67%),Plectranthus(4.67%),Asplenium(3.67%),Helychrisum(3.67%)and Pteris(2.80%).3)There are almost 70%indigenous plants in Mt.Kenya are herbs,almost 13%are shrubs,9.80%are trees,3.83%are lianas and 4.05%are climbers.The two kinds of forest vegetations(Fa and Fb)have the highest species number and density,then Bamboo zone(B)and Heath zone(E),and Afroalpine vegetation(A).Nival zone(Ad)and Transitional Forest(Fe)have the most poor species number and density.Plants y-diversity is a skewness distribution pattern along with the altitudinal gradients,and herbs have the most important contribution to this distribution pattern,while woody plants and lower vascular plants did not show a significant upward trend at first,there are gradually decreased along with altitudinal gradients.Totally,the ratio values of woody plants and herbaceous plants are radually decreased along with altitudinal gradients,i.e.,there descent rate of herbaceous plants is smaller than that of woody plants.4)More than 60%vascular plants of Mt.Kenya are in pan-Atrican distribution partern,almost 21%plants are distributed globally,9.55%are endemic in tropical East Africa,3.61%are endemic in Kenya,and 1.35%are endemic in Mt.Kenya.Wide-spreading plants(Wordwide and pan-African)occupied 82%of total plants in Mt.Kenya,in which Asteraceae(125 species),Poaceae(111 species)and Fabaceae(83 species),Asplenium(25 species)and Cyperus(25 species)are biggest families or genera.Narrowly distributed plants(endemic in tropical East Africa and Kenya)occupied 13.16%of total plants,in which Asteraceae(25 species)and Senecio(8 species)are the biggest family and genus,respectively.There are 21 endemic species in Mt.Kenya,which belong to 17 genera and 13 families,in which Asteraceae(5 species)have most species.Dendrosenecio keniensis is the representative plant of these 21 endemic plants,which contributes to the well-known Afroalpine Vegetation with other Asteraceae and Campanulaceae species.There are 54 exotic plants in Mt.Kenya,which belong to 46 genera and 24 families,in which,Asteraceae(10 species),Fabaceae(8 species)and Solanaceae(5 species)are the three biggest families,and 57.41%of exotic plants are oringinated from America,25.93%from Eurasia,9.26%from Africa and 7.41%from Australia.5)From our research,there are 75 new recorded plants in Mt.Kenya,which belong to 61 genera and 35 families,in which 54 species(46 genera,29 families)are from the identification of our own specimens(SAJIT),21 species(19 genera,13 families)are from specimens of other herbaria.In addition,three new speices,Sedum keniense(Crassulaceae),Zehneria subcoriacea(Cucurbitaceae)and Cissampelos keniensis(Menispermaceae),are described from Mt.Kenya.