An 
The river banks are occupied by poplars and immense tufts 
of grass (Erianthus). 
East of the Amu Darya we are on the desert of shifting 
sand again, and then the large oasis of Buchara is reached. 
The sun is shining on green fields, tall poplars and brown 
clay houses. This is our first camping place. 
During these past days we have while traversing them 
acquired a preliminary knowledge of three of the greater 
plant formations of Transcaspia, namely the Clay-desert, the 
Sand-desert and the Riverside Thickets. The first we have seen 
in its luxuriant spring aspect characterized mainly by short- 
lived annuals; the second, seen at its worst, is distinguished 
by the exceptionally severe conditions under which only a 
few, specially equipped plants are able to live; the third is a 
fringing or gallery-forest (‘‘Galleriewald’’) rigidly limited to 
the banks of the river. 
It is the object of this contribution to describe these and 
other formations more closely. First, however, it will be 
necessary to consider the plant-formations of Transcaspia re- 
cognised by earlier writers and to explain our choice of 
names used to designate the formations in the following 
pages: 
In the Caspian Depression-territory — extending from 
the southern limit of the forest in European Russia to the 
‘Caucasus and the border-mountains of Persia —, GRISEBACH 
recognises three formations, namely Grass-steppe, Sand-steppe 
and Salt-steppe (I p. 455). The first of these has a soil with 
humus and is the south Russian steppe which does not come 
within the scope of this work. Under Salt-steppe he records 
a series of other “formations’ (p. 461) between which, how- 
ever, he does not distinguish sharply. The following three 
are noteworthy: 1) Dry Clay-steppe with a few Saxauls, an- 
nual Chenopodiaceae or Artemisia fragrans or Anabasis aphylla, 
2) More moist steppe with bushes of social Salsolaceae and 
Tamarisks, 3) Salt-swamps. 
Borszczow distinguishes 3 “areas” (see p. 24), namely 
Salt-desert, Clay-desert and Moving-sand-desert besides two, 
which lie outside our area. Finally Antonow has in ad- 
dition to “Mountain-Flora”, five formations namely Loess- 
