STRUCTURE AND HISTORY OF PLAV. 210 
APPENDIX C. 
The Tussock- Form of the Reed in the Norfolk Broads. 
As already stated, the tussock-form of the reed was first observed on the 
river Yare, in the Broads of Surlingham and Strumpshaw. The forma-. 
tion of conspicuous tussocks there, as compared with other places in the 
Broads, is, I think, due to a series of special circumstances which have caused! 
the tussock-form of growth to predominate over the creeping (see p. 248). 
The tussocks on the Yare apparently result from horizontal immobility. 
They are situated along a narrow and, for the Broads, deep channel which. 
passes through Surlingham fen and connects the few tiny broads still 
remaining. The water in this channel is in some places as much as 6 feet 
(1:8 m.) in depth at high tide, a depth too great for horizontal rhizomes. 
to invade, Further, if a shoot happens to invade a shallower spot in the 
channel, it is, as a rule, eventually cut off, as the channel is kept open for- 
rowing boats. 
In a single summer, Glyceria aquatica, Sm., which edges most of the. 
channels and broads of the Yare, with its trailing branches almost covers. 
the Surlingham channel, which is almost lost to sight just before the annual 
cutting, whilst on the landward side, Glyceria also prevents Phragmites from. 
extending its range. 
Thus Phragmites is effectually prevented from spreading horizontally, 
the formation of vertical shoots being alone possible; hence apparently the. 
extremely conspicuous tussocks of Surlingham (see РІ. 22. Во. 1). 
APPENDIX D. 
The lists of plants of the Norfolk Broads and of the Delta of the Danube. 
which follow are very small ones, and are to be regarded only as more or less 
typical samples of the floras of these two regions. In the delta obviously 
many more species remain to be discovered, since Cladium Maviscus, R. Br., 
and Naias marina, Linn., both frequent species, are recorded here as new for 
the Dobrogea, and as regards the Norfolk Broads the preparation of really: 
adequately arranged lists has hardly begun. The East Anglian broads and 
rivers are apparently far richer in water-loving plants than the Danube in 
Rumania. 
The nomenclature followed here is that of Hooker’s* third edition for 
the British plants, and of Grecescu's Conspectul f for the Rumanian. In. 
most cases I possess the exsiccata of the Rumanian plants used for 
identification. 
* Hooker, J. D., * The Student's Flora of the British Islands," Third Edition, 1881. 
T Grecescu, D., “ Conspectul Florei României,” 1898. 
