OUTLINES OF BOTANY. xvii 



158. The principal kinds of dry fruits are 



the Capsule or Pod* which is dehiaoent. When ripe the pericarp usually slits longitudinally 

 into as many or twice as many pieces, called valves, as it contains cells or placentas. If these 

 valves separate at the line of junction of the carpels, that is, along the line of the placentas or 

 dissepiments, either splitting them or leaving them attached to the axis, the dehiscence is 

 termed septieidal ; if the valves separate between the placentas or dissepiment, the dehiscence 

 is loculicidal, and the values either bear the placentas or dissepiments along their middle line, 

 or leave them attached to the axis. Sometimes also the capsule discharges its seeds by slitu, 

 chinks, or pores, more or less regularly arranged, or bursts irregularly, or separates into two 

 parts by a horizontal line ; in the latter case it is said to be drcumsciss. 



the Nut or Achene, which is indehisoent and contains but a single seed. When the pericarp 

 is thin in proportion to the seed it encloses, the whole fruit (or each of its lobes) has the 

 appearance of a single seed, and is so called in popular language. If the pericarp is thin and 

 rather loose, it is often called an Utricle. A Samara is a nut with a wing at its upper end. 



159. Where the carpels of the pistil are distinct (125) they may severally become as many 

 distinct berries, drupes, capsules, or achenes. Separate carpels are usually more or less 

 compressed laterally, with more or less prominent inner and outer edges, called sutures, and, if 

 dehiscent, the carpel usually opens at these sutures. A Follicle is a carpel opening at the inner 

 suture only. In some cases where the carpels are united in the pistil they will separate when 

 ripe ; they are then called Gocci if one-seeded. 



160. The peculiar fruits of some of the large Orders have received special names, which 

 will be explained under each Order. Such are the siliqua and silicule of Cruoiferffi, the legume of 

 Leguminosse, the pome of Pyrus and its allies, the pepo of Cuourbitacese, the cone of Coniferse, 

 the grain or caryopsis of Graminea), etc. 



§ 14. The Seed. 



161. The Seed is enclosed in the pericarp in the great majority of flowering plants, called 

 therefore Angiospenns or angiospermous plants. In Conifem and a very tew allied genera, called 

 Gymnosperms oi gymnospermous plants, the seed is naked, without any real pericarp. These truly 

 gymnospermous plants must not be confounded ^ith Labiata, Boraginece, etc., which have also 

 been falsely called gynospermous, their small nuts having the appearance of seeds (158). 



162. The seed when ripe contains an embryo or young plant, either filling or nearly filling the 

 cavity, but not attached to the outer skin or the seed, or more or less immersed in a mealy, oily, 

 fleshy, or horn-like substance, called the albumen or perisperm. The presence or absence of this 

 albumen, that is, the distinction between albuminous and exalbuminous seeds, is one of great 

 importance. The embryo or albumen can often only be found or distinguished when the seed 

 is quite ripe, or sometimes only when it begins to germinate. 



163. The shell of the seed consists usually of two separable coats. The outer coat, called the 

 testa, is usually the principal one, and in most cases the only one attended to in descriptions. 

 It may be hard and crustaceous, woody or bony, or thin and membranous (skin-like), dry, or 

 rarely succulent. It is sometimes expanded into icings, or bears a tuft of hair, cotton or wool, 

 called a coma. The inner coat is called the tegmen. 



164. Thefunicle is the stalk by which the seed is attached to the placenta. It is occasionally 

 enlarged into a membranous, pulpy, or fleshy appendage, sometimes spreading over a consider- 

 able part of the seed, or nearly enclosing it, called an aril. A strophiole or caruncle is a similar 

 appendage proceeding from the testa by the side of or near the f unicle. 



165. The Mlum is the soar left on the seed where it separates from the funicle. The 

 micropyle is a mark indicating the position of the foramen of the ovule (133) . 



166. The Embryo (162) consists of the Radicle or base of the future root, one or two 

 Cotyledons or future seed-leaves, and the Plumule or future bud within the base of the cotyledons. 

 In some seeds, especially where there is no albumen, these several parts are very conspicuous, 

 in others they are very difficult to distinguish until the seed begins to germinate. Their 

 observation, however, is of the greatest importance, for it is chiefly upon the distinction between 

 the embryo with one or with two cotyledons that are founded the two great classes of phseno- 

 gamous plants, Monocotyledons and Dicotyledons. 



1.67. Although the embryo lies loose (unattached) within the seed, it is generally in some 

 determinate position with respect to the seed or to the whole fruit. This position is described 

 by stating the direction of the radicle next to or more or less remote from the hilum, or it is 

 said to be superior if pointing towards the summit of the fruit, inferior if pointing towards the 

 base of the fruit. 



§ 15. Accessory Organs. 



168. Under this name are included, in many elementary works, various external parts of 

 plants which do not appear to act any essential part either in the vegetation or reproduction of 

 the plant. They may be classed under four heads : Tendrils and Hooks, Thorns and Prickles, 

 Hairs and Glands. 



* In English descriptions, pod is moce freqiaently used when it is long and nE^rrgw j capsule, or sometimes 

 pouch, when it is short and thick or broad. 



