236 



MISSOURI BOTANICAL GARDEN* 



South America, while Cassia has about 300 out of 412 in 

 the same region. 



In comparison with the above forms the distribution of 

 the Melastomataceae is of great interest. 



The family belongs to the tropical zone but is also repre- 

 sented in the subtropical, occurring between 30° N. and 

 40° S. Latitude. The family reaches its highest differen- 



America where 6 (I, IV, V, VII, X, XI) 

 exclusively found, 1 more (III) occurs 



of the tribes are 



in 



South 



and 



(XV) is found 



Am 



islands of the Pacific Ocean and tropical Africa. The 



other 7 are confined to the Old 



American tribes include 95 



genera 



The tropical 

 ee more are 



added by the two tribes of more general distribution while 

 the single genus (lihexia) in North America brings the 

 number of American genera up to 99, with about 2,000 



United 



(in this in 

 pared with 



of the 



) 



as com- 



g 



remainder of the range, 

 the Memecvleae ( Tribe 



th about 700 species from the 

 It is of interest to note that in 



XV), the 



S 



tribe occurring elsewhere, the dehiscence in the South 

 American genus (Olisbea is by some regarded as merely 

 a section of Mouriria) is by short slits which in many 

 cases much resemble pores while in the other genera it is 



that in the tribe 



s 



described as by longitudinal slits. Of this tribe there are 

 44 American and 101 Old World species. It will be noticed 



showing dehiscence by longitudinal 

 slits (XII, XIV, XV) 2 genera with 44 species are Amer- 

 ican while 10 genera with 156 species are found elsewhere. 

 These figures are certainly suggestive, and seemed more 

 so when it was found that the Apidae, the insects of the 



greatest importance in the fertilization of these forms, are 

 stronerlv represented in South America. India and Anstr.n- 



