_Endocarp_, the innermost layer, the stone. But more commonly only two portions of a drupe are distinguished, and are named, the outer one _Sarcocarp_ or _Exocarp_, for the flesh, the first name referring to the fleshy character, the second to its being an external layer; and _Putamen_ or _Endocarp_, the _Stone_, within. [Illustration: Fig. 375. Longitudinal section of a peach, showing flesh, stone, and seed.] 357. The typical or true drupe is of a single carpel. But, not to multiply technical names, this name is extended to all such fruits when fleshy without and stony within, although of compound pistil,--even to those having several or separable stones, such as the fruit of Holly. These stones in such drupes, or drupaceous fruits, are called _Pyrenæ_, or _Nucules_, or simply _Nutlets_ of the drupe. 358. Of Dry fruits, there is a greater diversity of kinds having distinct names. The indehiscent sorts are commonly one-seeded. [Illustration: Fig. 376. Akene of a Buttercup. 377. The same, divided lengthwise, to show the contained seed.] [Illustration: Fig. 378. Akene of Virgin's-bower, retaining the feathered style, which aids in dissemination.] 359. =The Akene or Achenium= is a small, dry and indehiscent one-seeded fruit, often so seed-like in appearance that it is popularly taken for a naked seed. The fruit of the Buttercup or Crowfoot is a good example, Fig. 376, 377. Its nature, as a ripened pistil (in this case a simple carpel), is apparent by its bearing the remains of a style or stigma, or a scar from which this has fallen. It may retain the style and use it in various ways for dissemination (Fig. 378). 360. The fruit of Compositæ (though not of a single carpel) is also an akene. In this case the pericarp is invested by an adherent calyx-tube; the limb of which, when it has any, is called the PAPPUS. This name was first given to the down like that of the Thistle, but is applied to all forms under which the limb of the calyx of the "compound flower" appears. In Lettuce, Dandelion (Fig. 384), and the like, the achenium as it matures tapers upwards into a slender beak, like a stalk to the pappus. [Illustration: Fig. 379. Akene of Mayweed (no pappus). 380. That of Succory (its pappus a shallow cup). 381. Of Sunflower (pappus of two deciduous scales). 382. Of Sneezeweed (Helenium), with its pappus of five scales. 383. Of Sow-Thistle, with its pappus of delicate downy hairs. 384. Of the Dandelion, its pappus raised on a long beak.] 361. =A Cremocarp= (Fig. 385), a name given to the fruit of Umbelliferæ, consists as it were of a pair of akenes united completely in the blossom, but splitting apart when ripe into the two closed carpels. Each of these is a _Mericarp_ or _Hemicarp_, names seldom used.