THE COAST-FLORA OF THE CLACTON DISTRICT. 
209 
repens , Hordeum maritimum and Arundo phragmitis. The 
salinity is very considerable in some places, judging by the 
succulence of certain leaves, which attained a thickness of quite 
two millimetres (Beta, A triplex portulacoides) . Rarely a Salt- 
cornia may be found showing the interesting phenomenon of 
having lost its succulence, except in a few internodes of the 
stem. Luxuriant colonies of Atriplex littoralis accompanied by a 
particularly leafless form of Polygonum aviculare cover some sea* 
walls near Stone Point. 
Other plants growing with preference on the cliff, though 
their connection with salt is doubtful, are Solarium dulcamara, 
Rubus fruticosus (Bramble), Reseda luteola (Weld or Yellow-weed), 
Smyrnum olusatrum (Alexanders), Pastinaca sativa (parsnip), 
Sedum acre (Wall-pepper), Helminthia echioides (Ox-tongue), etc. 
On the loose valley-gravel cliff, I have not observed any 
halophilous plants. The vegetation is mainly composed of 
species from the land above, weeds of cultivation, meadow grasses. 
Besides these, plants with good seed-dispersal apparatus and a 
capacity for holding the soil together, such as Tussilago farfara 
(colts-foot), Epilobium hirsutum (codlins-and-cream), Equisetum 
telmateia (in wet places), form what may be described as a land¬ 
slide vegetation. 
Mr. Shenstone, in his short account of the Essex coast- 
flora, mentioned the fact that certain littoral species occur on 
high mountains. Such is the case with Armeria vulgaris, Silene 
maritima, Plantago maritima and PI. coronopus (which are 
obviously closely related to PI. alpina) and Cochlearia officinalis. 
(Ecologically this is not difficult to understand. The absorp¬ 
tion of water is as difficult in the cold soil of high mountains as 
on the saline soil of the shore. The action of wind is strong in 
both cases, and rapid alternation of temperature causes in both 
cases rosette-formation. How they are connected historically, 
I cannot venture to say ; it seems probable that the coast-plants 
are relics from the glacial period, more or less modified. 
It is remarkable that most true halophytes belong to a few 
families, notably the Chenopodiaceae, Cruciferae, and Graminae. 
Many of our edible vegetables are descended from halophytes, 
e.g., beet-root, celery, cabbage, kale, spinach, horse-radish ; 
some of the commonest weeds are also halophilous, e.g., Orachs. 
This fact might find an explanation in the occurrence of a con- 
