182 I'LORA OF SOUTIIERX RHODESIA. 



In 1915 the Royal Society of South Africa published the 

 paper in which I brought together for the first time a record 

 of all the collections made to that date, so far as possible, 

 though it was not quite complete, as I did not get access to 

 the records of every collector. That paper was really a check 

 list of Ehodesian plants, Avith the addition of all information 

 then available as to distribution. Since that time our know- 

 ledge of the vegetation of Rhodesia has been considerably 

 increased, particularly in the direction of records of distribu- 

 tion. Additions to our list of species have not been very great, 

 only about five hundred new species being added in five years. 



If we compare Rhodesia with the Fnion, we find that our 

 conditions are, relatively speaking-, uniform, for we have no 

 such extremes of elevation and climate as are found in the 

 western coast region, with its rainfall of from two to four 

 inches at sea-level, or the 10,000 ft. Drakensberg-, with its 

 winter snows. Speaking generally", Sontliern Rhodesia belongs 

 to the great Cenlral African i)lateau, with an altitude of from 

 3,000 to 5,000 feet and an annual rainfall of from 15 to 40 

 inches. At the same time, it would be a mistake to regard 

 our floristic conditions, as being really liomog-eneous. for we 

 have mountains on the east rising- from 0,000 to 7,000 feet, 

 while there are parts of the country as low as 1,300 feet, and 

 relatively limited areas enjoy an annual rainfall of over 

 GO inches. 



It is hoped that we may soon be in a position to divide 

 Rhodesia into botaincal regions, and Mr. .1. S. lienkel is now 

 at work on this i)roblem, with assistance from the Geological 

 Survey Department and the Meteorological Branch of the 

 Agricultural Department. 



I should like here to emphasise tlie fact, not perhaps 

 sufficiently recognised, that the solution of the urgent problem 

 of getting a true knowledge of our local vegetation, its con- 

 stituents and its distribution, would be immensely accelerated 

 if some positive and active collaboration could be arranged 

 between the geologists, the surveyors and the botanists of the 

 country. The great practical importance of expediting such 

 acquisition of knowledge in a country largely awaiting settle- 

 ment need not be enlarged upon ; suffice it to say that so long 

 as our records of the indigenous flora of different districts 

 remains incomplete, and often quite vague, so long will it be 

 difficult to give safe advice as to what crops, what pasture 

 plants, and what trees can be established in any given place, 

 and thus the pastoral and agricultural industries will advance 

 less rapidly than might otherwise be the case. Further, the 

 initiatio)! of potential industries will be delayed for lack of 

 definite information regarding supplies of timber so essential 

 1 1 many of them. 



At this stage it may be of interest to place on record the 

 constituents of the flora of Southern Rhodesia so far as at 

 present known. Such analyses of the floristic elements have 

 been made for other regions of Africa, but, I believe, not 

 hitherto for Rhodesia. 



