66 
BOTANICAL TOUR IN THE LAKHIMPUR DISTRICT, ASSAM. 
rolepis exaltata both with scandent stems ; Antrophyum reticulaium 
with its sori arranged along the lines of venation and Vittaria elong- 
ata with dense masses of drooping grass like fronds. Of orchids, the 
most typical and extensive order of Epiphytes in tropical tegions^^ 
there are fewer representatives than one would expect to find. Den- 
drobtufHy Saccolabtum, ^ridesy Sarcantkus and Bulhophyllum are 
most in evidence. 
The shrubby vegetation forming the undergrowth is dense, more 
especially so in places where the light is not excluded by the- canopy 
of trees. In open parts where the forests have been more or less 
cleared away the commonest shrubs are M'^sa tndicay which so often 
monopolizes abandoned cultivated lands to the detriment of more 
useful vegetation in the Eastern Himalayas; Croton caudatus 
becoming a tree) ; Clerodendron tnfortunaium vj}\os>e white flowers 
in large open panicles exhale an overpowering fragrance j Solanum 
indicum Combretum chinense. On the river banks free of the 
larger competing vegetation are Homonota riparia which grows gre- 
gariously on river shoals sometimes covered by floods for months ; 
Funs heterophyllay Ficus pyrijormisy Ficus hispida^ Acacia Intsia 
and many more. On the borders of cleared tracts and even within 
them the small scrubby bushes are often completely enveloped by the 
subscandent fern, Gleichenia dichotoma and the climbing species, 
Lygodium microphylluniy while over all trails a wide spreading Sel- 
aginella» 
Their presence has been fostered by recent clearances of virgin 
forest and I have never yet met with these plants except in similar 
localities. Davalka tenuifolia and Pteris semipinnata have also 
effected a permanent footing on the steep sides of road cuttings and 
ditches in the vicinity, and as these five species of plants {and, of 
course, many others) do not exist in the natural forests around, one 
is puzzled to account for their apparently spontaneous appearance. 
The botanical traveller in the Himalaya (to speak from my expe- 
rience alone )'COuId without difficulty produce scores of instances 
proving the multiplication of many otherwise rare forms of plant life 
induced through the development of a country by means of cultiva- 
tion and roads. Similar conditions also materially hasten the extinc- 
tion of indigenous vegetation. 
In the confines of the forest the shrubby vegetation is for the 
greater part composed of species different from those noted in the 
more open tracts. 
For convenience of discussion it can be readily divided into erect 
and climbing shrubs. As examples of the former we may take Gar- 
