168 - 



already been referred to. They have also ephemeral shoots, 

 mesophytic in structure and arising from perennial hypogeal 

 parts. In other Hemicryptophytes the epigeal shoots live 

 through the whole summer, e. g. in species of Zygophyllum, 

 Anabasis, Statice, probably also in a few Cousinia and Astra- 

 galus; their shoots are xerophytic in structure and have this 

 biological character in common with the annual summer- 

 plants that the shoots die when winter sets in. 



No information is available on the few plants recorded 

 as biennials, for instance Tragopogon. It is unlikely that 

 the species of Tragopogon carry fresh leaves throughout the 

 whole summer. 



The Chenopodiaceae as a group are strikingly deficient 

 in hemicryptophytes, they have only 4 per ct. The Tama- 

 ricaceae and the Liliaceae have none at all. The paucity of 

 hemicryptophytes in the Chenopodiaceae, so many of which 

 seem specially adapted to desert-life, may perhaps be explain- 

 ed in this way, that this type is not well adapted to the 

 natural conditions prevailing during summer in the desert. 

 Yet the correctness of this supposition may be questioned 

 when we consider the Zygophyllaceae, likewise true summer- 

 plants and with 11 hemicryptophyte-species (69 per ct.). 



Of the remaining orders the Umbelliferae in particular 

 include a large number of hemicryptophytes all or most of 

 which are spring-plants. (See table 5). 



Next in order to the Hemicryptophytes (Table 3) follow 

 the Fanerophytes, the trees and shrubs. These all belong 

 to RAUNKLER'S Micro- and Nanofanerophytes. 



In the Transcaspian desert there are 11 per ct. Faner- 

 ophytes, about the same proportion as in the North-African 

 deserts (Libyan desert 12, Cyrenaica 9) and in Samos (9), 

 but much less than in Death Valley with 23 p. ct. On the 

 other hand, the South Russian Steppe shows only 5 per ct. 

 and the Spanish Steppe about the same number 1 ). Denmark 

 has 7, Stuttgart 9 per ct. (RAUNKLER). 



Only 14 out of 87 Fanerophytes in the list may still 

 be found flowering after July 1 st and of these 8 are Cheno- 



l ) WILLKOMM 1895 p. 280. 



