136 



Kali. We find dimorphism not only in the leaves but also in the fruit 

 of Salsola collina} Volkens 2 mentions Chenopodium, Atriplex and Sucecla 

 as examples of those genera of ChenopodiaceaB having dimorphic fruit ; and 

 to these Salsola (e. g. S. collina) might be added, where in one form the 

 fruiting-perianth becomes membranaceous and expanded into broad wings ; 

 while in another form, it is smaller and hardened. 3 In the latter form, an 

 interesting mode of dissemination may be accomplished. When the fruit 

 becomes mature, the connate base of the floral-leaves becomes thick and 

 hard, and assumes a nut-like form, which is ultimately released from the 

 branches. This nut-like body encloses one, two, or sometimes more fruits, 

 which are protected by the spiniscent apex of the leaves and bracts, some- 

 what resembling, but by no means exactly, the fruit of ' Tribulus terrestris 

 or of Tetragonia expansa, and on account of its lightness may be conveyed 

 to a distance by ocean currents. Yolk ens 4 classifies the modes of dissemina- 

 tion in Chenopodiacege into two classes, viz. those which are dispersed (i) 

 by animals, and (2) by winds. To the second class, he attributes many 

 species of Salsola. To this, again, we might add a third class (e. g. S. 

 collina), to which those plants disseminated by the ocean currents should 

 be included. 



In both the African and the Chinese plants, we find the fruiting- 

 perianth displaying a beautiful rosy colour. Whether the colour attracts 

 some animals, e. g. birds, which may effect dissemination, or insects, or 

 serves some other purposes, can only be determined by careful observations 

 on the spot. 



These and other features of minor importance exhibited by these plants 

 demonstrate as a whole striking cases of adaptation to environment emi- 

 nently characteristic of xylophilous plants. 

 ■ i 



1. Buxg-e (' Enumeratio plantaginearum Salsolacearumque central asiatic arum ' in Acta 

 horti petrop. VI, 1880, reprint, p. 32) points out the genera] heteromorphic habits of Salsola 

 collina; while careful descriptions of various forms of this species are given in Sir J. D. 

 Hooker's Flora of British India, V, p. 1 7. 



2. Volkens in Engler and Prantl's Natiirlich. Pflanzenfamilien, III, pt. 1, p. 49. 



3. Bunge in his 'Enumeratio Salsolacearum omnium in Mongolia hucusque collectarum' 

 (in Melanges Biologiques tires du Bulletin de I'Academie Imperiale des Sciences de St.- 

 Petersbourg, X, p. 295), distinguishes Salsola collina from S. Kali solely by the dorsally 

 gibbous perianth and by the minute spongy wings observed in the second, or the smaller, 

 form of the fruit of the former species. 



4. Volkens loc. cit. pp. 48-49. 



