BRYOPHYTA OF S. RHODESIA. 299 



and five of Hepaticae. A few localities are given by Brotherus 

 in a report of mosses collected by Brunnthaler in various parts of 

 South Africa in 1909 (2). 



The present list is principally drawn up from collections 

 made by Dr. Sim at various times, but especially in the course 

 of an extensive tour through the district in 1920, during which 

 the Zimbabwe Ruins, Khami Ruins, Matopos and Victoria Falls 

 were visited, and good collections made throughout. About the 

 same time Prof. Wager visited the district, covering the same 

 ground to a great extent, and his collections were sent to me for 

 determination. Mr. Eyles has collected mosses from time to 

 time, a good many of which have passed through my hands from 

 the British Museum, and from Dr. Sim, who has also sent me 

 a few collected by Mr. Teague around Umtali. A few of Mr. 

 Eyles' plants were collected by Dr. Nobhs and Mr. J. H. Henkel. 



The number of species listed below — about 125 — is not large, 

 and is without doubt capable of extension. At the same time, I 

 think it probable that the present list furnishes a much higher 

 percentage of the actual moss flora than would be expected in the 

 case of most areas of so large extent, and at the same time so 

 very slightly explored. This conclusion is based partly on the 

 general phytogeographical conditions of Southern Rhodesia, for 

 data as to which I am indebted to Dr. Sim. From these data — 

 detailed by Dr. Sim in the introduction to this paper — it is clear 

 that the district generally speaking is a xerophytic one, extremely 

 so in the western parts, less so, but still decidedly of that character 

 in the eastern. In these parts where Dr. Sim's collections were 

 mostly made, the percentage of species is obviously low as com- 

 pared with the number of individuals; mosses appear in fail- 

 quantity but of comparatively few species, and definitely xerophy- 

 tic in character. 



The one part of the district where one would expect a possibly 

 rich moss flora is that of the Zambesi Valley round the Victoria 

 Falls. The conditions of humidity and of temperature would 

 predispose one to expect something of the bryophytic flora of the 

 tropical rain-forest. The moss flora is, indeed, much richer there 

 in individuals, and their character is widely different from those 

 of the arid veld; but the number of species is somewhat disap- 

 pointing, and the relationship to the tropical moss flora is very 

 slightly marked. This, however, as Dr. Sim points out, is quite 

 explicable when one considers the isolated position of the area 

 in question. The actual part of the gorge which is kept moist 

 by the spray of the Falls is very limited, and a hundred yards 

 away from it, in any direction, takes us into the arid plateau. 

 That xerophytic conditions prevail even so close to the river is 

 clear from the fact that epiphytic mosses occur on the trees growing 

 here. Below the Falls the gorge is a deep, rocky chasm where the 

 vegetation is of a succulent xerophytic type, and Bryophyta 

 almost disappear ; while before reaching the Falls the river has 

 travelled through hundreds of miles of arid country, so that this 

 part of its course is entirely isolated from the tropical rain-forest 

 4a 



