BOTANICAL, INDEX. 
29 
Fig. 94 . 
natural size, at E a front view of a single flower, at C a cross-section or diagram of a 
flower, showing the relative position of the component parts, and at D the perinth 
(flower) laid open to exhibit the general form before expanding, also to give the form 
and position of the stamens. Fig. 93 represents at A a single fruit from the panicle, 
covered with the dried and adhering perinth (flower) ; at B a transverse section of a 
fruit, showing the position of the single perfect ovule, (seed), and the two abortive 
seed, with the three partition walls dividing the fruit into 3-cells; at C a vertical sec- 
tion of the fruit, and at D an ovule (seed) in position. 
Although this is one of our hardiest native plants, it is also one of the first to feel 
the effect of frost, for we often find their foliage killed by our light, early frosts in 
autumn, while other aquatic plants do not seem to be injured from it in the least. 
P. cordata, variety Angustifolia , has triangular-elongated and tapering leaves, 
scarcely heart-shaped at thie base. {Gray.) 
P. cordata , variety Lancifolia, Mulh., (not Lanceolata, Sir J. P.,) leaves lance-oblong 
to lance-linear ; habitat, Southern States, (U. S. N. A.); in bloom during April and 
May. {Gray.) 
P. vaginalis is esteemed as a medical plant in Japan, Java, and on the Caromandel 
coast, where a decoction of its root is used in diseases of the liver and stomach ; pul- 
verized and mixed with sugar, it is administered for asthma; it is chewed for the 
toothache; its leaves, bruised and mixed with milk, are administered in cholera, and 
its young shoots are edible. (J. D. Hooker, in Dps. and Ana. Bot.) 
In conclusion we would say, these plants are certainly among our prettiest 
aquatic flowering plants, but from their great abundance are often considered inferior 
to many more expensive but less effective ones, for which reason they are almosj 
entirely ignored in American floriculture; but in Europe, where they are brought 
into requsition by practical landscape gardeners, they are fully appreciated and 
extensively employed. 
