— 211 - 



with salt-concretions ; especially is this the case with T. 

 hispida and T. Karelini, where these are very numerous. 



As regards the development of vegetative and floral 

 branches, the species of Tamarix may be divided into two 

 groups. In the first group the floral shoots appear on the 

 year-shoot of last year while the present year-shoot is purely 

 vegetative. This group includes Tamarix laxa, Meyeri, Andros- 

 soivii, florida, elongata, polystachya. This characteristic is 

 shown in T. laxa (tig. 47). The vegetative and floral shoots 

 are, however, not always separated as in this case, but may be 

 intermingled. A single one or several of the vegetative shoots 

 seen in fig. 47 will become rejuvenescence shoots, the remain- 

 der are short-lived assimilating shoots. All the vegetative 

 shoots, as will be noticed, are many times branched. The 

 species of this group flower early, during April and May, 

 and according to Bunge (1852 p. 8) they have as a rule 

 tetramerous flowers. 



The species of the second group bear the flowers at 

 the apex of the present year- shoot which has vegetative 

 branches at its base. To this group belong T. Pallasii, hispida, 

 Karelini, arceiithoides, Eiversmannii, karakalensis, Korolkowii, 

 leptostachya and pycnocarpa. 



The branch of T. hispida illustrated in fig. 48 is the 

 shoot of this year. All the lower branches of primary order 

 bear much-branched vegetative shoots at the base and inflor- 

 escences at the top, or they are purely vegetative. The 

 upper year-shoot branches are entirely floral. 



The species included here are said by Bunge (1. c.) to 

 have as a rule pentamerous flowers which open late, from 

 July to September. As the flowers arise on the outmost 

 part of the year-shoot and its branches, they cannot appear 

 until these axes have attained a certain stage of development. 



In this group as in the first, the flower axes and the 

 -greater part of the vegetative branches fall off, and only a 

 single one or a few become rejuvenating shoots. 



Short-lived vegetative branches may appear in all the 

 species on old year-shoots in the axils of leaves which have 

 fallen off. They may bear inflorescences as in the species 

 of the second group. 



14* 



