- 174 — 



gical types" in the sense adopted by Raunki^r, a method 

 of arrangement which offers the best opportunities for comp- 

 arison between morphological and biological characteristics, 

 especially those of shoot-structure and branching in relation 

 to the nature of the leaves. Amongst the various types I 

 have given most attention to those contributing to the summer- 

 aspect, i. e. the true Xerophytes, more especially the Fanero- 

 phytes and Chamaephytes. This course was adopted because 

 I had more material of these plants at my disposal, and 

 partly because of the special interest attached to the structure 

 of plants with persistent epigeal shoots. 



In what follows, the occurrence, foliage and ramification 

 of each species are described, flowering and fructification 

 being also referred to. Some of the descriptions are accompanied 

 by photographs of herbarium specimens, or by sketches some 

 of which are taken from material preserved in alcohol. So far 

 as material permitted, the anatomy of the assimilating organs 

 has been examined. Axial organs which are not assimilatory 

 I have not examined, first because the material was too 

 limited for such an investigation so that any comparative 

 conclusions would be rather doubtful, secondly in order to 

 limit the work, and finally because thorough descriptions of 

 the anatomy of the axial organs of a number of species are 

 given in B. Jonsson's valuable memoir. 



A. Fanerophytes. 



The trees and shrubs have been included as far as 

 possible. The descriptions begin with the "dry" plants and 

 proceed towards the more succulent. 



Eremosparton aphyllum F. & M. 



A leafless shrub or small tree, generally about 1 — 2 

 metres high, rarely exceeding 4 metres. It is at home in the 

 sand-desert where it is one of the most characteristic plants. 

 The roots are long and some are horizontal. According to 

 Palezki.7, the roots are capable of producing aerial shoots 

 and although this species might for this reason be cultivated 



