Nardoo (Marsilea macropus), a plant of the order Marsileæ (see RHIZOCARPS), the only plant of that order which is used in any way by man. It is found in Australia, and affords important supplies of food to the natives of some regions; it has also been of great use to some exploring parties. It grows in places occasionally covered with water; vegetating whilst moisture abounds, and then exhibiting abundance of green clover-like foliage, the leaves consisting of four leaflets at the top of a stalk some inches in length. When the water dries up, the remains of the plants are often covered with dried mud.
It is then that the spore-cases are gathered for food. They are oval, flattened, about an eighth of an inch in length, hard and horny, and requiring considerable force to pound them when dry, but becoming soft and mucilaginous when moistened. The spore-cases, pounded with their contents, are made into cakes like flour.