The Nardoo appears generally to be considered the seed of the lentil, or some other plant of the bean tribe, whereas it belongs to one of those cryptogamic or flowerless plants, which, like ferns and mosses, do not produce perfect seeds, but are increased by cellular bodies named spores. It belongs to the genus Marsillea, order Marsilleaceae, and that class of sexual or flowerless plants called Acrogens, which have distinguishable stems and leaves, in contra-distinction to Thallogens, in which stems and leaves are indistinguishable, as sea-weeds, fungi, and lichens. The part used for food is the Involucen Sporangium, or spore case, with its contained spores, which is of an oval shape, flattened, and about one-eighth of an inch in its longest diameter; hard and horny in texture, requiring considerable force to crush or pound it when dry, but becoming soft and mucila ginous when exposed to moisture. The natives pound it between two stones, and make it into cakes like flour. The spores vegetate in water, and root in soil at the bottom, where the plant grows to maturity. After the water dries up, the plants die, and leave the spore cases on, in many instances quite covering the surface of the dried mud. It is then that they are gathered for food. On the return of moisture, the spore cases softened, become mucilaginous, and discharge their contents to form a fresh crop of plants. The foliage is green, and resembles clover somewhat, being composed of three fleshy leaflets on the top of a stalk a few inches in length.
(See page 2166.--[Chapter IX.])