Butter-Nut, the product of Caryocar nuciferum, a native of tropical South America. The large nuts, known also as saowari or suwarow nuts, are the hard stone of the fruit and contain an oily nutritious seed. The genus Caryocar contains ten species, in tropical South America, some of which form large trees affording a very durable wood, useful for shipbuilding.

Leaf of Butterwort.

A, leaf of Butterwort (Pinguicula vulgaris) with left margin inflected over a row of small flies. (After Darwin.) B, glands from surface of leaf by which the sticky liquid is secreted and by means of which the products of digestion are absorbed.