THE PLANT ECOLOGY OV THE COAST lU-JI/L' OF NATAL. '383 



the strand plants. The growth-forms of the component 

 species, the extraordinary abnnd.ince of climbing phmts, the 

 characters of the foliage and many other features which will 

 be described in detail later, all reflect the tropical nature of 

 the vegetation. 



More detailed investigation discloses the fact that the 

 majority of the component species either actually extend 

 northwards through the tropics or have close tropical 

 affinities. About 84 per cent, of the genera and 36 per cent. 

 of the species are recorded in the "^ Flora of 'JVopical Africa'; 

 but if that publication were brought up to date, according to 

 present information, the percentage of tropical species would 

 certainly be found to be even greater. An analysis of the 

 flora of the coast belt from this standpoint is given in the 

 following table : 



Table I.— Natal Coast Belt. 



Genera and species. 



Coast lielt genera . 

 Tropical coast belt genera 

 Pei-rentage of tropical genera 

 Coast belt species . 

 Tropical coast belt species 

 Percenta.ge of ti'opical species 



Total. 



620 

 520 

 83-9 

 1500 

 545 

 36-3 



Doubtful records have been neglected and the total number 

 of species is almost certainly more than 1500. It would 

 appear at the outset, both from the purely ecological and 

 from the floristic standpoints, that there are good reasons 

 why the coast belt of Natal should be considered as part of 

 a distinct subtropical region which would include this portion 

 of Bolus' south-eastern region and also much of his Kalahari 

 region— the subtropical parts of the Transvaal. To test this 

 possibility more fully a further detailed analysis of the 

 separate families has been made on the lines adopted by 

 Bolus. It is set forth in Table II. The percentage of 

 tropical species in each family is also given. 



VOL. 4, PART 2. 26 



