Page:Encyclopædia Britannica, Ninth Edition, v. 4.djvu/161

Rh FOllMS OF FRUIT. J B T A IS Y 151 &quot;orras of ruit. Simple fruits arc either dry or succulent, the pericarp, in the former instance, remaining more or less foliaceous in its structure, and sometimes being incorporated with the seed, while it is in the latter thick and fleshy or pulpy. The achoenium is a dry unilocular monospcrmous incle- hiscent fruit, the pericarp of which is closely applied to the seed, but separable from it. It may be solitary, forming a single fruit, as iu the Dock (fig. 294), and in the late IV. Cashew, where it is supported on a fleshy peduncle ; or aggregate, as in Ranunculus (figs. 254, 295), where several achasnia are placed on a common elevated receptacle. In the Strawberry the achaenia (fig. 154) are aggregated on a convex succulent receptacle. In the Hose they are supported on a concave receptacle (fig. 155), and iu the Fig the succulent receptacle completely encloses the achenes (fig. 150). In Dorstenia (fig. 1G3) the achenes are situated on a flat or slightly concave receptacle. In the Rose the aggregate achamia with their covering are sometimes col- oo o o lectively called cynarrhodum. It will thus be remarked that what in common language are called the seeds of the o O Strawberry, Rose, and Fig, are in reality carpels, which are distinguished from seeds by the presence of styles and stigmas. The styles occasionally remain attached to the ackaonia, in the form of feathery appendages, as in Clematis, and they are called caudate. In Composita3, the fruit, which is sometimes called cypsela, is an achoenium (fig. 197), to which the pappose or obsolete calyx remains ad herent. Such is also the nature of the fruit in Dipsacacese. &quot;When the pericarp is thin, and appears like a bladder surrounding the seed, the achajnium is termed a utricle, as in Amarantacese. When the pericarp is extended in the form of a winged appendage, a samara or samaroid achoenium is produced, as in the Ash (fig. 281), Common Sycamore (fig. 29G), and Hiraea. In these cases there are usually two achainia united, one of which, however, as in Fraxinus oxyphylla (fig. 281), may be abortive. The wing is either dorsal, that is, it is a prolongation from the median vein (fig. 29G, o) or it is margined, that is, formed by the lateral veins. It surrounds the fruit longitudinally in the Elm. When the pericarp becomes so incorporated with the seed as to be inseparable from it, as in grains of Wheat, Maize, Oats (fig. 297), and other Grasses, then the name kilo IX. Fig. 297. Fig. 298. Fig. 299. lulu lii. Fin. 21)7. Caryopsis or single-seeded grain of Oats (Arena). The fruit and Bccd n ro Incorporated. The pericarp o bears the styles and stigmas, mid encloses tlie seed t, with its albumen, or perisperm, a, and its embryo, consisting of the cotyledon c, the geimnule y, and the root r. Fir,. 29S. Calyx and fruit of Comfrey (Symphytmn), cut vertically. The fruit is divided by the folding of the ovary into four single-seeded portions or achsenia, two of which are seen in the figure, and the style appears to arise from the base of the carpels. 1*1 o. 290. Flower of Fennel (Focnicuhim vulgare), one of the Umbcllifenc, cut vertically, showing the fruit /, composed of two single-seeded carpels, or achenes, united, so as to fomi a cremocarp. The pendulous seeds are seen in the carpels or mcriearps. The two styles are seen at the apex of the fruit, with their dilated bases formed by an epigynous disk. The points (apicula) of the petals p arc turned inwards. The calyx tube is adherent to the fruit, and the limb of the calyx is often obsolete. &amp;lt;;iryopsis is given. There are some fruits which consist of two or more acliacnia, although originally the carpels w r erc united into a syncarpous pistil, as in Labiatie and Boraginaceae (fig. 298). To this form of schizocarpie fruit, as well as to that of Tropaiulum and Mallow, the name carcerulus is given. The cremocarp, or the fruit of Umbelliferoe (figs. 292 and 299), is composed of two achajuia Plate VII united by a commissure to a carpophore, from which they are suspended at maturity. It is sometimes denominated diachcenium, from the union of two achaenia, which in this instance receive the name of mericarps or hemicarps. The nut or glans is a dry one-celled indehiscent fruit with a hardened pericarp, surrounded by bracts at the base, and, when mature, containing only one seed. In the young state the ovary contains two or more ovules, but only one comes to maturity. It is illustrated by the fruits of the Hazel and Chestnut, which are covered by leafy bracts, in the form of a husk, and by the Acorn, in which the bracts and receptacle form a cupula or cup (fig. 147). The parts of the pericarp of the nut are united so as to appear one. In common language the term nut is very vaguely applied both to fruit and seeds. The drttpe is a succulent usually inonospermal and unilocular indehiscent fruit, with a pericarp easily distin guishable into epicarp, mesocarp, and endocarp. This term is applied to such fruits as the Cherry (fig. 282), Peach, Plate XIL Plum, Apricot, Mango, Walnut, Nutmeg, and Date. The endocarp is usually hard, forming the stone (putamen) of the fruit, which encloses the kernel or seed. The mesocarp is generally pulpy and succulent, so as to be truly a sarco- carp, as in the Peach, but it is sometimes of a tough tex ture, as in the Almond, and at other times is more or less fibrous, as in the Coco-nut. In the Almond there are often two ovules formed, only one of which comes to perfection. In the Walnut, prolongations from the endocarp, which is of two layers, extend into the substance of the seed, and give rise to its characteristic convoluted lobate appearance. This fruit has been sometimes called tryma. In the Rasp berry and Bramble several drupes or drupels arc aggregated so as to constitute an ctccrio. The follicle is a dry monocarpellary unilocular polyspermal (many-seeded) fruit, dehiscing by the ventral suture. It is rare to meet with a solitary follicle forming the fruit. There are usually several aggregated together, either in a circular manner on a shortened receptacle, as in Hellebore, Aconite, Delphinium, Aquilegia (figs. 300, 301) Crassulace;e (fig. 172), Butonius, and Asclepiadaceas ; or in a spiral manner on an elongated receptacle, as in Magnolia, Banksia, and Liriodendron. Occasionally, follicles dehisce by the dorsal suture, as in Magnolia grandiflora and Banksia. The legume or pod is a dry monocarpellary unilocular poly spermal fruit, dehiscing both by the ventral and the dorsal Plate V suture. It characterises Leguminous plants, as the Bean fi S- 7. and Pea (fig. 256). In the Bladder-senna it retains its leaf-like appearance, and forms an inflated legume. In some Legummosse, as Arachis, Cathartocarpus Fistula, and the Tamarind, the fruit must be considered a legume, although it does not dehisce. The first of these plants pro duces its fruit underground, and is called earth-nut ; the second has a partitioned legume and is schizocarpic ; and both the second and third have pulpy matter surrounding the seeds. Some legumes are schizocarpic by the formation of constrictions externally. Such a form is the lomentum or lomcntaceous legume of Hedysarum coronarium (fig. 293), Coronilla, Ornithopus, Entada, and of some Acacias. In Medicago the legume is twisted like a snail, and in Ca^sal- pinia coriaria, or Divi-divi, it is vermiform or curved like a worm in Carnricliaelia the valves give way close to the suture, and separate from it, leaving a division. Sometimes the number of seeds is reduced, as in Erythrina monospernia and Geoftroya supcrba, which arc one-seeded, and in Ptero- carpus and Dalbergia, which are two-seeded. The berry (bacca) is a succulent syncarpous polyspermal uuilocular indehiscent fruit, with seeds immersed in a pulpy