254 
FLORA OF THE SUNDRIBUNS. 
by fruit-eating birds are not plentiful ; the three species of Vitis^ with 
the three species of LoranthuSy a species of Viscum, a Cuscutay a 
Ficus {F. retusa var. nitidd) and the Leeay are perhaps the least 
equivocal instances. Except the Leeay which may equally well have 
been introduced by water, it is to be noted that all these species are 
either climbers or parasites. The Ficus, it is true, does not persistently 
climb, but it begins life as an epiphytic climber. Species intro- 
duced by wind agency are nearly thrice as numerous. They include 
thirteen epiphytic orchids, vis, an Oberonia, two Dendirobiay 
a Cirrhopetalutny a Trias, two Luisive, three Saccolahia, two Sar~ 
cant hi y and a Cleisostoma, all with minute and very light seeds ; eight 
epiphytic vascular Cryptogams, vis. :—Asplenium falcatum. Poly- 
podium quercifolium, adnascens and irioides, a Vittaria, a Drymo- 
glossunty Acrostichum scandens, a Lycopodium and a Psilotum, all 
reproduced by means of minute spores. The obscure P ter is [P . 
vittata), if one may judge from’its figure and description, should belong 
to this category. The other wind-introduced species are mostly climb- 
ers, their seeds being provided with a pencil of hairs that serves as a 
parachute ; they include Parsonsia spiralis (Apocyneae), Dregea 
volubilis and Finlaysonia obovata (Asclepiadaceae) which are rooted 
in the ground, with two epiphytic Asclepiads, Hoya parasitica and 
Dischidia nummularia. The only swamp-forest tree for which intro- 
duction by wind seems unequivocal is Dolichandrone Rheedei, which 
has seeds with large membranous marginal wings. One non-epiphytic 
fern, Acrostichum aureumy is possibly also a wind-introduced species. 
Species that almost certainly owe their presence in the Sundribun 
forests to their seeds having been washed down from Upper India or 
from the Himalayan slopes by the great rivers are less numerous than 
those introduced by wind-agency. As might be expected they vary 
considerably in habit and include among herbaceous forms Alpinia 
Allughas, Typha elephantinay^.ndi T. angustafa, Cryptocoryne ciliaia 
and Orysa sativa ; among climbers, Teramnus fle.xilis, Derris 
scandens, Caesalpinia Nuga Mesoneuron cucullatum, Entada 
Pursvethtty Acacia concinna and A. Intsia, Mallotus repanda, 
Jpomosa paniculata, Calamus tenuis and Dvemonorops Jenkinsia- 
nus\ among erect species, Tamarix gallica, Micromelum pubescenSy 
Flemingia congesta, Acacia tomentosa and Cyclostemon assamicus. 
The two most striking features among the species of this list, as will be 
seen on consulting the systematic census of Sundribun plants, are the 
* This species is also capable of introduction by the sea, and is plentiful on 
the coasts of the Andamans : in our northern forests it is, however, possibly a 
riverine immigrant ; at the sea-face, where it also occurs, it is quite probably a 
sea-introduced species. 
