192 FLORA INDTCA. 



that which we have indicated as prevalent in similar localities 

 in Nipal. The forest is most luxuriant where the higher 

 mountains overhang the plains, and becomes stunted or dis- 

 appears entirely where a great river debouches on the plain. 

 In Garhwal, west of the Ganges, the forest which skirts the 

 Siwalik hills is less extensive, but many parts of the Dehra 

 Dhun are densely wooded. A species of Calamus which grows 

 in its jungles marks the western limit of that genus along 

 the Himalaya. West of the Jumna the vegetation changes 

 rather suddenly. A similar change has already been indi- 

 cated at the same place in the plain's vegetation (page 161), 

 but the forest belt close to the mountains, being always more 

 humid than the plain at a distance from them, their vegeta- 

 tion is never the same. The gigantic Bombaw, and the lofty 

 trees of Nauclea, Lagerstrcemia, Conocarpus, Terminalla, Ster- 

 culia, and others, and the scandent species of Butea, Bauhmw, 

 Millettia, Ventilago, etc., have however disappeared, and spi- 

 nous bushes or stunted trees of Zizyphns Jujuba, Butea fron- 

 dosa, Cassia Fistula, Acacia Arabica and Catechu, form thej 

 greater part of the jungle, mixed with Diospyros cor at 

 Adhatoda Vasica, and Isora corylifolia. In the extreme west; 

 Acacia modest a becomes very abundant, and beyond the Je- 

 lam the flora is identical with that of the lower Afghan mB* 

 The tropical vegetation advances far within the mountains, 

 ascending the valleys of the great rivers, and corresponding 

 in character with the forest belt without, but often rather 

 drier. In eastern Knmaon the humid valley of the Sarju it» 

 filled with dense forest. The curious palm Wallichia oblonr/i- 

 folia has there its western limit, and a pepper, a Pothos, an 

 arborescent Aralia, and a few other plants indicative ol hu- 

 midity, still linger in its recesses. The valley of the Ganges 

 is much drier and contains little forest, and the tropical por- 

 tions of the Jumna and the Satlej are quite bare. In the 

 Satlej valley, Afghan forms, unknown further cast, begin to 

 make their appearance,— Paliurus and Oka cuspidate, being 

 the most conspicuous. To these are added, in the Cheiuu 



