Floivering Plants and Ferns oj the Cape Peninsula. 223 



ascertain, peculiar to Southern Africa, and the great majority to its 

 South-western Eegion. 



Besides the above there are twenty genera each containing 15 

 or more species, viz., GUffortia, 23 ; Heliophila, 22 ; Satyr kmi, 

 Scirpus, each 21 ; Muraltia, Lobelia, and Thesinm, each 18 ; Tetraria, 

 17 ; Hermannia, Pliylica, Indigofcra, MorcBa, and Tliamnochortus, eack 

 16 ; Agathosvia, Serruria, Gnidia, Pterygodiwn, Anthericum, Jwicus, 

 and Elegia, each 15. The average is reduced by the very large 

 number of 204 genera, which are represented by only one species 

 each ; of these, 42 are monotypic genera. 



It would be interesting to adduce data of other similar Floras for 



the sake of comparison with that of the Cape Peninsula. Strictly 



^speaking these should be of peninsulas, or islands near a continent, 



of nearly equal area, and in the same latitude. Unfortunately no 



observations bearing any near approach to these conditions are here 



.available. I can only subjoin a few w^hich may be suggestive to the 



reader : — 



Square miles. Genera. Species, 



about 



Tasmania 22,633 394 1,063 



Natal 21,150 756 2,360 



Sicily 9,860 619 2,549 



Madeira 300 366 710 



Cape Peninsula ... 197 485 2,117 



Isle of Wight 155 376 867 



Hong Kong 29 566 1,056 



Ischia 18 389 792, 



Eemarkable Absence of Certain Orders. 



It is not, however, merely by the vegetation actually present 

 that the character of any particular Flora, as compared with others, 

 is to be judged, but also by what is absent. In this respect that of 

 the Cape Peninsula presents certain marked peculiarities. 



In the first place it is a notable and somewhat unexpected 

 circumstance that the large Orders Myrtace^, Apocynace^, and 

 Acanthace^ are wholly absent — not a single species having been 

 hitherto detected within our limits. Yet of the first there are 9 or 

 10, of the second probably over 30, and of the last 195 enumerated 

 species, dispersed throughout extra-tropical South Africa. It is true 

 that these are chiefly eastern in their distribution (only a few 

 occurring in the south-western districts), and belong to what I have 

 elsewhere termed the Sub-tropical Eegion ; nevertheless it is remark- 



]5 



