A CENSUS OF THE rNDlAN POLYGONUMS. 
44 ^ 
In the foregoing table it will be noticed that Koentgia has the 
smallest number of species and is least widely distributed in India, 
while Persicaria has the greatest number of species and is most 
widely distributed. Avicularia is especially distinctive to the North- 
West Frontier and the North-West Himalaya Bistort Cephalophilon^ 
Aconogon^ and Tiniaria are characteristic of the Himalayan range from 
west to east. Amblygonon is practically restricted to the sub-sub- 
areas of low altitude. Echinocaulon is strongly represented in Assam. 
Altitudinal Distribution in India. 
The following diagram gives the altitudinal range of every species 
with the more important varieties occurring in India. Each of the squares^ 
represents one thousand feet vertically as indicated on the left margin 
Any further facts regarding the altitudinal range of any species can 
easily be incorporated by the reader simply ‘ inking in the appro- 
priate squares. The diagram is not of course likely to be absolutely 
correct for every species, but the range of error probably does, not go 
much beyond five hundred feet either way. 
The species with the greatest vertical range is (21) Polygonum 
viviparum Linn., which is found from 5,000 feet up to 18,000 feet. 
Several species have a very restricted range. Of these among the 
more alpine forms are (15) Polygonum mollideforme Boiss., (23) 
Polygonum perpusillum Hook, f, (25) Polygonum Bis t ort a hmn.y (75) 
Polygonum Hookeri Meisn., and (76) Polygonum nummularifolium 
Meisn. Amongst the low-level species (18) Polygonum to*mentosum 
Willd., (19) Polygonum limhatum Meisn!,' and (64) Polygonum 
pedunculare Wall,, may be singled out. 
The study of the altitudinal range of some of the varieties of 
Polygonum plebejum R. Br. lends some additional support to the 
writer’s opinion, based on morphological grounds, that some of those 
varieties might well be raised to ^specific rank. It is . seen that 
Polygonum plebejum and its variety elegans have the same vertical 
range, while the varieties indica and hrevifolia are also altitudinal- 
twins. On the other hand the variety Grfffithii has a distinctly re- 
stricted range ; Polygonum tomentosum and Polygonum limbatum^ 
which sre so remarkably like each ether morphologically, are also- 
linked by their latitudinal and altitudinal distribution. 
The diagram of general altitudinal distribution is followed by a 
similar one for the sections. The pages containing the former are to 
be held sideways. i ^ . 
