OX SOME WATER PLANTS. 
”5 
to the Primulacece, it is an adventurous member of a family 
of land plants which has taken to water-life. Its affinities are 
easily recognized when the flower is examined. The whorls 
of delicate lilac, yellow-throated flowers closely resemble some 
of the Chinese Primulas, often grown in greenhouses, such as 
P. malacoides ; but the leaves are unlike those of any Primula. 
The blade on either side of the midrib is divided into stiff nar¬ 
row segments with a pectinate arrangement. Adapted to 
their surroundings the tissues enclose large air spaces, and on 
the under surface of the leaf are many short glandular hairs, 
which probably secret mucilage. Similar hairs are present on 
the flower stalk. The succulent stems are fastened below to the 
mud by slender white roots glistening from the enclosed air 
spaces. Throughout the year the circles of bright green leaves 
may be seen under the water, often just beyond the collector’s 
reach ; and this is not without its advantage when the plant 
is in flower, for the sight of a bed of Water Violet in blossom 
is apt to create in the heart of even the most philosophical botan¬ 
ist a craving to possess at least one piece. 
I have put these notes together to illustrate how rich our 
neighbourhood is in Water plants, and in the endeavour to show 
how much the interest in these plants is enhanced if their 
structure is studied in relation to their surroundings. 
In conclusion I wish to thank Mr. Dennis for the trouble he 
has taken in making lantern s ides from my drawings, and 
also for the generous loan of his own beautiful slides showing 
water plants growing in their natural haunts. 
DESCRIPTION OF TEXT FIGURES. 
Fig. i. —Diagrammatic section of a pond with Water Plantain ( Alisma 
Plantago), showing seedlings in deeper water with ribbon-leaves only, 
and in shallow water with aerial leaves ; also a full-grown flowering 
plant with submerged, floating and aerial leaves. 
Fig. 2.—Arrowhead (Sagittaria sagittifolia ). Plants in deep water with 
ribbon-leaves only, and one in shallow water with leaves mostly 
aerial and sagittate. Tubers occur on underground shoots. 
Fig. 3. —Free end of a ribbon-leaf of Arrowhead, showing venation. 
Fig. 4. —Small Bur-reed ( Sparganium simplex), showing deep and shal¬ 
low water plants connected by runners ; the stream bed is seen in 
section 
Fig. 5. —Free end of ribbon-leaf of S. simplex, showing venation. 
Fig. 6 .—Great Sedge (Scirpus lacustris), showing plants in deep water 
with ribbon-leaves only ; in shallower water with ribbon-leaves and 
flowerless scapes ; and in very shallow water without ribbon-leaves 
and with both flowerless and flowering scapes ; river bed seen in sec¬ 
tion. 
Fig. 7. —Free end of ribbon-leaf of Great Sedge, showing venation. 
