SUCCESSIONS OF THE SAT TAL VALLEY. 251 



Tal, and lakes with gently sloping shores such as a swampy lake just 

 to the north-east of the valley. 



Streams are occupied by such pioneers as Debregcasia hypoleuca 

 of the Nettle Family and Colebroohia oppositifolia of the Mint Family, 

 then the rosaceous shrubs, then trees of the Laurel Family with 

 perhaps a few Rhododendrons which have temporarily gone a little 

 below their normal range, then, in the altitude of Sat Tal valley, 

 generally the oak climax. 



Lakes with steeper shores have following the aquatics of deep 

 water the willow, Salix daphnoides, near the water's edge. This 

 adapts itself to the shifting seasonal water level by putting out roots 

 at high water mark which hang high and dry when the water is low. 

 As the lake decreases for topographical reasons, the willow is followed 

 by rosaceous shrubs leading ultimately to the oak. 



Lakes with gentle slopes, or swamps, have a large quota of sub- 

 mersed and floating aquatics. These are succeeded by Typha angus- 

 tata, Scirpus spp., and Polygonum lanigerum, which are followed, as 

 the water becomes more shallow, by Acorns calamus and Panicum 

 paspaloidcs. Later comes the wet meadow and then the Berbcris- 

 Rosaccac formation leading to the oaks. 



Special Features of the Vegetation. 



About fifteen of the tree and shrub species in the valley are above 

 the altitudinal range given for them by Brandis (2). Probably the fact 

 that the valley is a depression protected from cold winds by the peak 

 to the north, has allowed plants to grow out of their ordinary range. 



A noteworthy feature of this altitude in the Himalayas is the 

 abundance of lianas. Over twenty of the woody plants in the appended 

 species list are climbers, to say nothing of many climbing herbs. A 

 single tree was noticed which supported eight different species of 

 climbers. Bauhinia vahlii is the king of lianas here. The Naini 

 Tal Gazeteer (8) states that at times it grows so profusely that a 

 single plant will cover a quarter of an acre of forest. It has been 

 found a great pest to the forester as it overshadows and stunts the 

 growth of many trees. So prolifically does it ooppice that the foresters 

 have difficulty in suppressing it. The valley has three genera of 

 climbing aroids, four species of Vitis, and numerous leguminous clim- 

 bers, climbing figs., etc. One of the most widespread lianas is the 

 common ivy. Partaking of the nature of both lianas and epiphytes, 

 and embracing tree trunks with a network of roots often to the extent 

 of considerable injury to the tree embraced are certain species of 

 Ficus, as F Rumphii, (the so-called " strangling figs ") and Heptopleu- 

 rum venulosum, a member of the Araliaceae. 



