Section Xiv. the Fruit.

345. =Its Nature.= The ovary matures into the Fruit. In the strictest sense the fruit is the seed-vessel, technically named the PERICARP. But practically it may include other parts organically connected with the pericarp. Especially the calyx, or a part of it, is often incorporated with the ovary, so as to be undistinguishably a portion of the pericarp, and it even forms along with the receptacle the whole bulk of such edible fruits as apples and pears. The receptacle is an obvious part in blackberries, and is the whole edible portion in the strawberry.

346. Also a cluster of distinct carpels may, in ripening, be consolidated or compacted, so as practically to be taken for one fruit. Such are raspberries, blackberries, the Magnolia fruit, etc. Moreover, the ripened product of many flowers may be compacted or grown together so as to form a single compound fruit.

347. =Its kinds= have therefore to be distinguished. Also various names of common use in descriptive botany have to be mentioned and defined.

348. In respect to composition, accordingly, fruits may be classified into

Simple, those which result from the ripening of a single pistil, and consist only of the matured ovary, either by itself, as in a cherry, or with calyx-tube completely incorporated with it, as in a gooseberry or cranberry.

Aggregate, when a cluster of carpels of the same flower are crowded into a mass; as in raspberries and blackberries.

Accessory or Anthocarpous, when the surroundings or supports of the pistil make up a part of the mass; as does the loose calyx changed into a fleshy and berry-like envelope of our Wintergreen (Gaultheria, Fig. 366, 367) and Buffalo-berry, which are otherwise simple fruits. In an aggregate fruit such as the strawberry the great mass is receptacle (Fig. 360, 368); and in the blackberry (Fig. 369) the juicy receptacle forms the central part of the savory mass.

Multiple or Collective, when formed from several flowers consolidated into one mass, of which the common receptacle or axis of inflorescence, the floral envelopes, and even the bracts, etc., make a part. A mulberry (Fig. 408, which superficially much resembles a blackberry) is of this multiple sort. A pine-apple is another example.

349. In respect to texture or consistence, fruits may be distinguished into three kinds, viz.--

Fleshy Fruits, those which are more or less soft and juicy throughout;

Stone Fruits, or Drupaceous, the outer part fleshy like a berry, the inner hard or stony, like a nut; and

Dry Fruits, those which have no flesh or pulp.

350. In reference to the way of disseminating the contained seed, fruits are said to be

Indehiscent when they do not open at maturity. Fleshy fruits and stone fruits are of course indehiscent. The seed becomes free only through decay or by being fed upon by animals. Those which escape digestion are thus disseminated by the latter. Of dry fruits many are indehiscent; and these are variously arranged to be transported by animals. Some burst irregularly; many are

Dehiscent, that is, they split open regularly along certain lines, and discharge the seeds. A dehiscent fruit almost always contains many or several seeds, or at least more than one seed.

351. The principal kinds of fruit which have received substantive names and are of common use in descriptive botany are the following. Of fleshy fruits the leading kind is

352. =The Berry=, such as the gooseberry and currant, the blueberry and cranberry (Fig. 371), the tomato, and the grape. Here the whole flesh is soft throughout. The orange is a berry with a leathery rind.

353. =The Pepo=, or Gourd-fruit, is a hard-rinded berry, belonging to the Gourd family, such as the pumpkin, squash, cucumber, and melon, Fig. 372, 373.

354. =The Pome= is a name applied to the apple, pear (Fig. 374), and quince; fleshy fruits, like a berry, but the principal thickness is calyx, only the papery pods arranged like a star in the core really belonging to the carpels. The fruit of the Hawthorn is a drupaceous pome, something between pome and drupe.

355. Of fruits which are externally fleshy and internally hard the leading kind is

356. =The Drupe=, or Stone-fruit; of which the cherry, plum, and peach (Fig. 375) are familiar examples. In this the outer part of the thickness of the pericarp becomes fleshy, or softens like a berry, while the inner hardens, like a nut. From the way in which the pistil is constructed, it is evident that the fleshy part here answers to the lower, and the stone to the upper face of the component leaf. The layers or concentric portions of a drupe, or of any pericarp which is thus separable, are named, when thus distinguishable into three portions,--

Epicarp, the external layer, often the mere skin of the fruit,

Mesocarp, the middle layer, which is commonly the fleshy part, and

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.

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 Pyrenae, 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.

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 Compositae (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.

361. =A Cremocarp= (Fig. 385), a name given to the fruit of Umbelliferae, 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.

362. =A Utricle= is the same as an akene, but with a thin and bladdery loose pericarp; like that of the Goosefoot or Pigweed (Fig. 386). When ripe it may burst open irregularly to discharge the seed; or it may open by a circular line all round, the upper part falling off like a lid; as in the Amaranth (Fig. 387).

363. =A Caryopsis, or Grain=, is like an akene with the seed adhering to the thin pericarp throughout, so that fruit and seed are incorporated into one body; as in wheat, Indian corn, and other kinds of grain.

364. =A Nut= is a dry and indehiscent fruit, commonly one-celled and one-seeded, with a hard, crustaceous, or bony wall, such as the cocoa-nut, hazelnut, chestnut, and the acorn (Fig. 37, 388.) Here the involucre, in the form of a cup at the base, is called the CUPULE. In the Chestnut the cupule forms the bur; in the Hazel, a leafy husk.

365. =A Samara, or Key-fruit=, is either a nut or an akene, or any other indehiscent fruit, furnished with a wing, like that of Ash (Fig. 389), and Elm (Fig. 390). The Maple-fruit is a pair of keys (Fig. 391).

366. Dehiscent Fruits, or Pods, are of two classes, viz., those of a simple pistil or carpel, and those of a compound pistil. Two common sorts of the first are named as follows:--

367. =The Follicle= is a fruit of a simple carpel, which dehisces down one side only, i. e. by the inner or ventral suture. The fruits of Marsh Marigold (Fig. 392), Paeony, Larkspur, and Milkweed are of this kind.

368. =The Legume= or true Pod, such as the peapod (Fig. 393), and the fruit of the Leguminous or Pulse family generally, is one which opens along the dorsal as well as the ventral suture. The two pieces into which it splits are called VALVES. A LOMENT is a legume which is constricted between the seeds, and at length breaks up crosswise into distinct joints, as in Fig. 394.

369. The pods or dehiscent fruits belonging to a compound ovary have several technical names: but they all may be regarded as kinds of

370. =The Capsule=, the dry and dehiscent fruit of any compound pistil. The capsule may discharge its seeds through chinks or pores, as in the Poppy, or burst irregularly in some part, as in Lobelia and the Snapdragon; but commonly it splits open (or is dehiscent) lengthwise into regular pieces, called VALVES.

371. Regular Dehiscence in a capsule takes place in two ways, which are best illustrated in pods of two or three cells. It is either

Loculicidal, or, splitting directly into the loculi or cells, that is, down the back (or the dorsal suture) of each cell or carpel, as in Iris (Fig. 395); or

Septicidal, that is, splitting through the partitions or septa, as in St. John's-wort (Fig. 396), Rhododendron, etc. This divides the capsule into its component carpels, which then open by their ventral suture.

372. In loculicidal dehiscence the valves naturally bear the partitions on their middle; in the septicidal, half the thickness of a partition is borne on the margin of each valve. See the annexed diagrams. A variation of either mode occurs when the valves break away from the partitions, these remaining attached in the axis of the fruit. This is called Septifragal dehiscence. One form is seen in the Morning-Glory (Fig. 400).

373. The capsules of Rue, Spurge, and some others, are both loculicidal and septicidal, and so split into half-carpellary valves or pieces.

374. =The Silique= (Fig. 401) is the technical name of the peculiar pod of the Mustard family; which is two-celled by a false partition stretched across between two parietal placentae. It generally opens by two valves from below upward, and the placentae with the partition are left behind when the valves fall off.

375. =A Silicle or Pouch= is only a short and broad silique, like that of the Shepherd's Purse, Fig. 402, 403.

376. =The Pyxis= is a pod which opens by a circular horizontal line, the upper part forming a lid, as in Purslane (Fig. 404), the Plantain, Henbane, etc. In these the dehiscence extends all round, or is circumscissile. So it does in Amaranth (Fig. 387), forming a one-seeded utricular pyxis. In Jeffersonia, the line does not separate quite round, but leaves a portion for a hinge to the lid.

377. Of Multiple or Collective Fruits, which are properly masses of fruits aggregated into one body (as is seen in the Mulberry (Fig. 408), Pine-apple, etc.), there are two kinds with special names and of peculiar structure.

378. =The Syconium or Fig-fruit= (Fig. 405, 406) is a fleshy axis or summit of stem, hollowed out, and lined within by a multitude of minute flowers, the whole becoming pulpy, and in the common fig, luscious.

379. =The Strobile or Cone= (Fig. 411), is the peculiar multiple fruit of Pines, Cypresses, and the like; hence named Coniferae, viz. cone-bearing plants. As already shown (313), these cones are open pistils, mostly in the form of flat scales, regularly overlying each other, and pressed together in a spike or head. Each scale bears one or two naked seeds on its inner face. When ripe and dry, the scales turn back or diverge, and in the Pine the seed peels off and falls, generally carrying with it a wing, a part of the lining of the scale, which facilitates the dispersion of the seeds by the wind (Fig. 412, 413). In Arbor-Vitae, the scales of the small cone are few, and not very unlike the leaves. In Cypress they are very thick at the top and narrow at the base, so as to make a peculiar sort of closed cone. In Juniper and Red Cedar, the few scales of the very small cone become fleshy, and ripen into a fruit which closely resembles a berry.