BEN 
is said to grow here. These latter species indicate that “Ta- 
kyr” is also closely related to the Clay-desert. 
From what has been said about the Salt-deserts, we 
can deduce the following characleristics of the formation: it 
consists of annual or perennial Halophytes of which a few 
are dwarf-bushes, very few are bushes (Tamarix) and none 
are trees. The plants grow scattered on a very saline soil. 
There is no spring flowering period but all the plants vege- 
tate throughout the summer or, at least, far into it. ‘This 
last feature I regard as the chief distinguishing characteristic 
between this formation and the Clay-desert. 
The formation does not fall in with GRISEBACH'S Salt- 
steppe or Borszczow’s Salt-desert both of which occur to some 
extent in the Clay-desert. This is indicated by the fact that 
both authors mention trees and bushes as constituents of 
the vegetation. 
CHARTER: 7 
The formation of the Clay-Deserts. 
Clay-deserts are distinguished here as areas which have 
a clay substratum, and which do not contain salts to the 
extent that they to a greater amount come to view on the 
surface. This concept is to some extent identical with “The 
area of the Clay-deserts” in Borszczow, but parts of his 
Salt-desert also belong here. ANronow’s formation of the 
“Loess-steppe” belongs here, likewise “the Clay-desert’” with 
the exception of the saline places, which are here classed 
under the preceding formation. 
According to many authors, Clay-deserts are very ex- 
tensive in the lowland of Transcaspia (comp. Borszczow above 
p. 25, and ANTONOW p. 32), and RICHTHOFEN regards them as 
“the true normal steppes of Central-Asia”. 
The soil of the Clay-deserts differs from that of the 
Salt-deserts by its greater dryness. When these two forma- 
tions are found together, the Salt-desert always occupies the 
deeper parts. The saline ground-water cannot diffuse up to 
