— 26 — 



chai-acterized by few, but exceedingly characleristic plant forms, 

 and a terrible monotony. — Of the plants (329 species) in 

 this formation, 10, gs per ct. are shrubs. The proportion of 

 perennials and biennials to annuals is 1:0,7. 



BoRSzczow's percentages for the families already named 

 are as follows for the area of the clay-desert: 



29,6 per ct. of Ranunculaceae of the whole area. 



The most frequent species are Artemisia fragrans and 

 A. monogyna; these alone cover large tracts and present a 

 most melancholy picture. They are frequently accompanied by 

 Salsola crassa, S. lanata, Brachylepis (Anabasis) salsa and Ana- 

 basis tatarica, sometimes with Saxaul (Haloxglon Ammoden- 

 dron), and Ferula persica, Rheum caspicum and Calligonum 

 Calliphgsa. 



"The occurrence of these (the three last-named species) 

 is so closely correlated with the soils of this area that it 

 is possible with the aid of only a few specimens to deter- 

 mine with great certainty the character and physiognomy 

 of the sub-flora from which they are taken." 



The plants mentioned are almost the only ones to be 

 found in the clay-deserts after the second half of April when 

 the sun becomes very jjowerful. In spring the flora is richer, 

 during the flowering season of species of Algssum, Megacar- 

 paea, Tauscheria, Euclidium, Matthiola, Chorispora, Echinosper- 

 mum, Onosma, Phelipaea, Allium (A. caspicum), Tulipa patens, 

 and Rhinopetalum Karelini. These plants are the "spring de- 

 corations of the desert flora", but unfortunately they are too 

 quickly lost again. A richer vegetation of roses with Spiraea 

 and Elaeagnus oecurs in the deep ravines on the margin of 

 the Usturt. 



3) The area of the Salt-deserts stretches over a very 



