Fig. 130.—Scarlet Horse-chestnut.
Fig. 131.—Yellow Horse-chestnut.
Fig. 132.—Nut of the Buckeye. vary considerably; as, for example, in the Scarlet Horse-chestnut (Æ. rubicunda), the calyx is tubular (see a in fig. 130), and there are but four petals, the upper two of which (b) are narrower than the lower ones (c), and have bearded claws. This species has sometimes eight stamens. In the Yellow Horse-chestnut, or yellow flowered American Buckeye, the upper petals (a in fig. 131) are very much smaller than the lower ones (b), and both have very long claws. There are four petals, which conceal the stamens, of which there are frequently only six. The seed of Pavia has only a small hilum, which resembles the pupil of an eye (see fig. 132); and hence the genus has received its American name of Buckeye. In one species (P. macrostachya), the nut is eatable, and very much resembles that of a Sweet Chestnut when boiled in milk. The stamens in this species are much longer than the petals, and they give a peculiarly light and elegant appearance to the flowers; which, unlike those of the other species, do not appear till the latter end of summer or autumn.
ORDER XLVI.—RHIZOBOLEÆ—THE CARYOCAR TRIBE.
Trees of large size, natives of tropical America. Caryocar nuciferum produces the Suwarrow, or Butter-nut of the fruiterers’ shops.