332 WILLIS : MORPHOLOGY OF THE PODOSTEMACBÆ 
very soon leaves of 3-4 cm. long are produced, and after a 
few months, in August or September, leaves may be 
commonly found of as much as 30 cm. long. The shoot in 
the Ceylon form usually grows more or less erectly, while 
in the Anamalai form it is more prostrate, but otherwise the 
two are very similar. Each shoot exhibits a certain amount 
of dorsiventrality, the side next to the fork of the thallus 
being the upper and slightly concave, while the other side 
is lower and convex ; the basal portion of the shoot flattens 
out into a sort of foot, figured by Warming, who has 
described these shoots in detail. The dorsiventrality shows 
itself in other ways also. PI. XYI., fig. 8, shows a section of 
the top of a shoot through the leaves, and shows the slight 
concavity of the upper side ; the vascular bundles form a 
curved line, concave upwards, and the leaves themselves 
show a distinct dorsiventrality, which resembles that of the 
cupules of Lawia, in that the upper sides of the sheaths are 
thicker than the lower. The lower sides, Avhile thinner, are 
also larger in surface than the upper. We shall find these 
characters much more pronounced in the leaves at the bases 
of the flowers in Dicræa and other subsequent genera. 
Occasionally in the Ceylon, and usually in the Anamalai 
form, the stem branches at the base, but more commonly 
there is no branching in the former until it has reached a 
height of 0’5-2 cm. and is ready to flower. When fully 
grown, one of these shoots may have a height of as much 
as 3 cm. and bear as many as 20 leaves, each 20-30 cm. long. 
The stems are produced near together upon the thallus, 
so that when a plant is well-grown in September it may have 
30 or 40 such stems, and the great mass of reddish-green 
leaves waving in the water like seaweeds upon the rocks of 
the coast, forms a very striking sight. A portion of such a 
plant is figured in PI. XV. ; the separate shoots on the left 
show their construction and the thallus joining them. The 
leaves themselves have been described by Warming; it may 
be noted that the very young ones are redder than the fully 
groAvn leaves, that the upper surfaces are hairy, and that 
