BOTANY. 



BOTANY. 



hut green, white, or yellow ; in the two latter | as in the pea ; incomplete, when some part. 



cases they are termed variegated), &c. They 

 are tubular, awl-shaped, three-edged, ever- 

 preen, &c. Compound leaves consist of two 

 or more leaflets, combined by a common foot- 

 stalk, as in the rose; they are binate \vhen 

 they consist of two leaflets ; ternate, of three, 

 &c.; pinnate when several proceed sidc\v;iy.s 

 or laterally from the common footstalk, as in 

 the rose. Leaves are sometimes twice aiid 

 thrice compounded. 



The flower is the most essential, yet the most 

 transitory part of plants. By means of the 

 seed, which it is the great agent in producing, 

 plants may be indefinitely multiplied and per- 

 petually renewed; whereas all other modes of 

 propagation, by cuttings, grafts, &c., are but 

 extensions of an individual. Hence, though 

 many plants, from unfavourable modes of cul- 

 tivation, &c., are seldom known to blossom, 

 yet Providence has wisely ordained that no 

 plant is incapable of producing and perfecting 

 seed. As our systems of botany are founded 

 chiefly upon the flower, we will proceed to 

 consider it at large. A flower is divided into 

 seven parts: 



1. The calyx, or outer covering, resembling 

 leaves in texture ; is not present in many 

 flowers, as the tulip. 



There are six kinds of calyx: 1. The peri- 

 anth is close to, and forms part of, the flower, 

 as in the rose, and is, in fact, the only true 

 calyx. 2. The involucre is an appendage to 

 the one form of inflorescence, namely the um- 

 bel It is remote from the corolla, as in all 

 the umbelliferous plants, carrot, &c. 3. The 

 spathe is a floral appendage which bursts lon- 

 gitudinally, being more or less remote from 

 thr flower, as in the snow-drop, narcissus, &c. 

 4-. The glume, or husk, is the peculiar calyx or 

 chaff" of the grasses, as in wheat, &c. 5. Pere- 

 chaetium, a scaly sheath, enclosing the fertile 

 flowers of some mosses. 6. Volvo, is the mem- 

 brane that covers the parts of fructification or 

 gills of the fungi, as in the common mush 

 room; but it is also applied to the fleshy cover- 

 ing which encloses some fungi when young. 



2. The corolla, or more delicate coloured 

 Jeaves or leaf, properly called petals, is situ- 

 ated within the calyx. This is absent in many 

 flower.5. It comprehends both the petal and 

 the nectary. By petal is meant what are com- 

 monly called the coloured leaves of a flower. 

 By nectary is meant an appendage to the co- 

 rolla, supposed to be for the purpose of secret- 

 ing honey. The little cells, for example, at 

 the bottom of the flower of the crown imperial 

 each full of a sweet liquid, are called necta- 

 ries, but they vary in form and situation in 

 different flowers. When a corolla is formed 

 of one petal, it is said to be monope'almis. It 

 may be be.U-*lwpcil, as in the Canterbury bell ; 

 funnel-shaped, as in lungwort (Pulmonaria) ; 

 talver-slwpcd, as in the primrose ; wh eel-shaped, 

 the same as the preceding, only with a shorl 

 tube, as in the borage ; ringent, like the mouth 

 of an animal, as in the dead nettle; personate, 

 like the mask of an animal, as in snap-dragon. 

 Corollas of more than one petal are termed 

 polypetalous. It is cruciform, as in the wall- 



found in kindred flowers, is wanting. 



3. The stamen or stamens are essential lor 

 the perfecting of the seed, and are only absent 

 in double flowers, in which they are changed 

 into petals. They vary in different species, 

 from a single one to several hundreds, and 

 surround the pistil or pistils, which occupy 

 the centre of the flower. A stamen usually 

 consists of two parts; the filament, or slender 

 stem, which is sometimes absent, bearing 

 otherwise on its summit the anther, a cellular 

 organ of various forms in different species of 

 plants, being the part for holding the pollen. 



4. The pistil or pistils are in the centre of 

 the flower, and usually fewer in number than 

 the stamens. They are sometimes situated in 

 flowers distinct from the stamen, and even on 

 different plants. No seed can be perfected 

 without the pistil, which consists of the ger- 

 men, or rudiment of the fruit and seed, and, of 

 course, is never absent. The style, or little 

 stem proceeding from the germ, which is not 

 essential, serving chiefly to elevate the stigma 

 this must always be present : it varies in form 

 and size, being either scarcely more than a 

 point, or forming an orbicular head, or being 

 variously lobed. 



5. The seed-vessel is the germen enlarged, va- 

 rying in form, texture, and size in almost every 

 species. What old botanists called naked seeds 

 are seed-vessels or carpels containing only one 

 seed, and which do not open when ripe ; the 

 strawberry, wheat, maize, are examples. The 

 only naked seeds are those of the fir cones, and 

 the CycadecB. 



There are seven kinds of seed-vessels: 1. 

 A capsule is woody or membranous, containing 

 one or more cells, as in the poppy. 2. A pod 

 is long, dry, and solitary, formed of two valves, 

 divided by a linear partition into two cells, as 

 in the wall-flower. 3. A legume is solitary, 

 formed of two oblong valves without any par- 

 tition, consequently is one-celled, as the pea. 

 4. A drupe has a fleshy coat, closely enclosed 

 in a hard nut, as the cherry, peach, &c. 5. A 

 pome has a fleshy coat, enclosing a capsule, as 

 the apple, pear, &c. 6. A Icrry is fleshy, con- 

 taining its seed or seeds within its pulp, with- 

 out valves, as the currant. A compound berry 

 is instanced in the blackberry, &c. 7. A cone 

 is a catkin hardened into a seed-vessel, as in 

 the fir, birch, &c. 



6. The seed. To the perfecting of this part 

 all the other parts of the fructification, and 

 even of the whole plant, are subservient; an- 

 nuals perish immediately after it is perfected, 

 and in our climate evenperennials begin to droop 

 as soon as it is ripe. A seed consists of seve- 

 ral parts: 1. The embryo is the part the wel- 

 fare of which all the other parts unite in pro- 

 moting. It is the rudiment of the future plant. 

 It is very apparent in the bean, pea, &c., and 

 has the form of a heart in the walnut. It is 

 usually within the substance of the seed, as in 

 the above instance ; in the grasses, however, 

 it is on the outside. 



Upon removing the skin of a pea or bean, 

 it divides easily into two parts ; these are the 

 cotyledons: this is the usual number. In the 



flower; rozaccous, as in the rose; papilionaceous, ' pine tribe they are four; in the grasses, &c., 

 ftiQ 



