Some Common Trench Flowers. 23 
town and in the canals of sugar plantations. They 
are very similar in appearance, having circular den- 
tated leaves with long flexible leaf-stalks. The flowers 
of both are white, but those of the last named plant are 
the largest. 
We now come to plants that are not very ornamental 
and far from attra6live, except on close inspe6tion, when 
one's interest increases the more he studies and ex- 
amines them. 
If on searching amongst the rank vegetation of some 
weed covered trench, one should chance on a slender look- 
ing plant that brings to his memory the lucky four-leaved 
Shamrock, he may be sure that he has found a specimen 
of Marsilea polycarpa. But where are the flowers ? Let 
him carefully examine the leaf-stalks and he will see at 
their bases a row of small woolly looking balls ; these 
will be the sporangidae, (Marsilea is a cryptogam) or 
reprodu6live organs of the little plant, which although 
not glowing in rainbow brightness, perform all the duties 
of the flowers that are so much admired in its higher 
brethren. 
Under the name of Nardoo the spore cases of a nearly 
allied Australian plant are colle6led by the natives and 
made into a sort of bread, and the survivor of the ill-fated 
exploration party under BURKE and Wells, would per- 
haps never have lived to relate the sad end of his com- 
rades, had he not found a bag of Nardoo in an old hut, 
where it had been left by the natives. 
Floating about between the tangled roots of the nume- 
rous weeds and grasses, and wherever the surface of 
the water is exposed, covering it like a thick green scum, 
some curious obje6ls may sometimes be seen, looking 
