MOUNTAIN FLORA OF GREAT ATLAS. 423 



much to do with the dearth of species, some parts of the range 

 even now presenting evidence of subterranean heat. 



The preponderance of Abyssinian forms is proved by almost 

 all of the genera and half the species being natives of Abys- 

 sinia, and by many other species being very closely related to, 

 or obvious representatives of, plants of that country. There 

 are, further, several of the genera and many of the species pecu- 

 liar to Abyssinia and the peaks of Biafra. 



The number of European genera amounts to 43, and 

 species to 26, the greater part of which are British. Very few 

 of them extend into South Africa. The greater part are Abys- 

 sinian ; the remarkable exceptions being Radiola, Scahiosa 

 auccisa, Luzula campestris, and Festuca gigantea, all of which, 

 however, may have been hitherto overlooked in Abyssinia. 



I find no other evidence of relationship between the Biafran 

 mountain Flora and that of Marocco than what is afforded by 

 the European species common to both. In most other respects 

 the Floras differ totally, the other mountain plants of Biafra 

 being Abyssinian or Cape types, or more nearly related to 

 tropical African ones. 



APPENDIX G 



On the Mountain Flora of Two Valleys in the Great Atlas of 



Marocco. 



By John Ball. 



Although an attempt to discuss the character and relations 

 of the Flora of a region so wide and so little known aa the 

 mountain region of the Great Atlas would as yet be quite 

 premature, it appears that the materials at our disposal suffice 

 for an examination of the vegetation of the valleys lying south 

 and south-west of the city of Marocco, which may be an 

 acceptable contribution to botanical geography. For this pur- 

 pose it seems best to limit the discussion to the two valleys 

 where our collections were sufficiently extensive to give a 

 tolerably complete representation of the vegetation, as far as 

 this was developed at the season of our visit, and to exclude 

 altogether the plants found along the skirts of the great range 

 below the level of about 1,200 metres above the sea. The Flora 

 of the zone below that level is largely mixed up with extraneous 



