103 
I 
ON SOME WATER PLANTS. 
Being a Presidential Address delivered to the Club at the Annual Meeting 
'on 29th March , 1919. 
By GULIELMA LISTER, F.L.S. 
(With 7 Illustrations.) 
T HOSE of us who are privileged to live on the borders of 
Epping Forest may find in its ponds and little pools 
unfailing interest and pleasure. Whether we visit them in winter 
when the delicate tracery of the hornbeams and birches is 
mirrored on the still surface of the water and the winter moths 
flutter down to meet their own reflections, or in summer when 
the blue dragon flies chase each other about the wealth of her¬ 
bage that has grown up, whether our interest is‘in animal or 
plant life, each pond will be found to have its own character 
and charm. I propose this afternoon to talk about a few of the 
Water plants that grow in our forest pools and in the Roding, 
and especially of those flowering plants that develop different 
forms of leaves, according to the conditions under which they 
live. 
Plants growing in water may have either aerial leaves, 
floating leaves, or submerged leaves ; some plants will have 
all three kinds of leaves. 
Such an one is the Great Water Plantain (Alisma Plantago), 
whose erect oval leaves and large much branched panicles of 
pale mauve honied flowers are conspicuous in late summer in 
most of our ponds. The seedlings produced from such plants 
have a very different appearance from their parents. If we 
follow the history of the light flat fruits that fall, float, and 
drift on the surface of the water, we find that they eventually 
sink to the mud at the bottom, where they pass the winter. In 
spring the seeds germinate and put forth a tuft of narrow trans¬ 
lucent leaves, two to six inches long, which might almost be 
mistaken for those of a grass. • These ‘ ribbon ’ leaves are well 
adapted for a submerged life. Being always bathed in water 
they have no stout external cuticle, such as leaves growing 
in the air require to protect them from drying winds ; they 
are supported by the water and so do not need tissues forming 
either the stiff armour or strong internal props such as are 
