22, we recognize four distinct whorls of leaves an outer whorl, the calyx of sepals; within it, another whorl, the parts alternating with those of the outer whorl, the corolla of petals; next a whorl of parts alternating with the parts of the corolla, the androecium of stamens; and in the centre the gynoecium of carpels. 23 is a diagrammatic representation of the arrangement of the parts of such a flower; it is known as a floral flower is supposed to be cut transversely, and the parts of each whorl are distinguished by a different these whorls the two internal, forming the sporophylls, constitute the essential organs of reproduction; the two outer whorls are the protective coverings or floral sepals are generally of a greenish colour; their function is mainly protective, shielding the more delicate internal organs before the flower petals are usually showy, and normally alternate with the sepals.

Sometimes, as usually in monocotyledons, the calyx and corolla are similar; in such cases the term perianth, or perigone, is applied. Thus, in the tulip, crocus, lily, speak of the parts of the perianth, in place of corolla, although in these plants there is an outer whorl calyx, of three parts, and an inner corolla, of a similar number, alternating with the parts of the calyx are in appearance like petals they are said to be petaloid, as in some cases the petals have the appearance of sepals, then they are sepaloid, as in plants, as Nymphaea alba, where a spiral arrangement of the floral leaves occurs, it is not easy to say where the calyx ends and the corolla begins, as these two whorls pass insensibly into each both calyx and corolla are present, the plants are dichlamydeous; when one only is present, the flower is termed monochlamydeous or apetalous, having no petals fig.

Sometimes both are absent, when the flower is achlamydeous, or naked, as in outermost series of the essential organs, collectively termed the androecium, is composed of the microsporophylls known as the staminal leaves or their most differentiated form each consists of a stalk, the filament fig. 25, f, supporting at its summit the anther a, consisting of the pollen-sacs which contain the powdery pollen p, the microspores, which is ultimately discharged gynoecium or pistil is the central portion of the flower, terminating the floral consists of one or more carpels megasporophylls, either separate fig.

The parts distinguished in the pistil are the ovary fig. The androecium and gynoecium are not present in all both are present the flower is hermaphrodite; and in descriptive botany such a flower is indicated by the symbol l.

When only one of those organs is present the flower is unisexual or diclinous, and is either male staminate, jor female pistillate, ?. A flower then normally consists of the four series of leaves - calyx, corolla, androecium and gynoecium - and when these are all present the flower is are usually densely crowded upon the thalamus, but in some instances, after apical growth has ceased in the axis, an elongation of portions of the receptacle by intercalary growth occurs, by which changes in the position of the parts may be brought in Lychnis an elongation of the axis betwixt the calyx and the corolla takes place, and in this way they are separated by an interval.

Again, in the passion-flower Passiflora the stamens are separated from the corolla by an elongated portion of the axis, which has consequently been termed the andro phone, and in Passiflora also, fraxinella fig. 27, Capparidaceae, tampa flowers same day delivery some other plants, the ovary is raised upon a distinct stalk termed the gynophore; it is thus separated from the stamens, and is said to be the successive whorls of the flower, disposed from below upwards or from without inwards upon the floral axis, are of the same number of parts, or are a multiple of the same number of parts, those of one whorl alternating with those of the whorls next it.

article In the more primitive types of flowers the torus is more or less convex, and the series of organs follow in regular succession, culminating in the carpels, in the formation of which the growth of the axis is closed fig. This arrangement is known as hypogynous, the other series calyx, corolla and stamens being beneath hypo- the other cases, the apex of the growing point ceases to develop, and the parts below form a cup around it, from the rim of which the outer members of the flower are developed around peri- the carpels, which are formed from the apex of the growing-point at the bottom of the arrangement is known as perigynous fig.

In many cases this is carried farther and a cavity is formed which is roofed over The flower stamens and FIG. - Monochlamydeous apetalous flower of Goosefoot Chenopodium, consisting of a single perianth calyx of five parts, enclosing five stamens, which are opposite the divisions of the perianth, owing to the absence of the petals.

- Stamen, consisting of a filament stalk f and an anther a, containing the pollen p, which is discharged through slits in the two lobes of the anther. article The pistil is placed on the receptacle r, at the extremity of the peduncle. - Calyx and pistil of Fraxinella Dictamnus Fraxinella. The pistil consists of several carpels, which are elevated on a stalk or gynophore prolonged from the receptacle.

by the carpels, so that the outer members of the flower spring from the edge of the receptacle which is immediately above the ovary epigynous, hence the term epigyny fig. When a flower consists of parts arranged in whorls it is said to be cyclic, and if all flower delivery seattle area whorls have an equal number of parts and are alternate it is eucyclic figs.

In Symmetry contrast to the cyclic flowers are those, as in Magnoli of the flower. aceae, where the parts are in spirals acyclic. Flowers which are cyclic at one portion and spiral at another, as in many Ranunculaceae, are termed spiral flowers the distinction into series is by no means easy, and usually there is a gradual passage from sepaloid through petaloid to staminal parts, as in the water-lily family, Nymphaeaceae figs.

3 1, 32, although in some plants there is no such distinction, the FIG. article 32, successive stages, a-f, in the transition from petals to stamens. Normally, the parts of successive whorls alternate; but in some cases we find the parts of one whorl opposite or superposed to those of the next some cases, as in the vine-family Ampelidaceae, this seems to be the ordinary mode of development, but the superposition of the stamens on the sepals in many plants, as in the pink family, Caryophyllaceae, is due to the suppression or abortion of the whorl of petals, and this idea is borne out by the development, in some plants of the order, of the suppressed a rule, whenever we find the parts of one whorl superposed on those of another we may suspect some abnormality.

A flower is said to be symmetrical when each of its whorls consists of an equal number of parts, or when the parts of any one whorl are multiples of that preceding it. Thus, a symmetrical flower may have five sepals, five petals, five stamens and five carpels, or the number of any of these parts may be ten, twenty or some multiple of five. 23 is a diagram of a symmetrical flower, with five parts in each whorl, alternating with each other. 33 is a diagram of a symmetrical flower of stone-crop, with five sepals, five alternating petals, ten stamens and five the number of parts in the staminal whorl is double that in the others, and in such a case the additional five parts form a second row alternating with the the staminal whorl especially it is common to find additional rows.

34 shows a symmetrical flower, with five parts in the three outer rows, and ten divisions in the this case it is the gynoecium which has an additional number of parts. 35 shows a flower of heath, with four divisions of the calyx and corolla, eight stamens in two rows, and four divisions of the fig. article 36 there are three parts in each whorl; and in fig. 37 there are three divisions of the calyx, corolla and pistil, and six stamens in two all these cases the flower is Monocotyledons it is usual for the staminal whorl to be double, it rarely having more than two rows, whilst amongst dicotyledons there are often very numerous rows of floral envelopes are rarely in which the number of parts in each whorl is the same, are isomerous of equal number; when the number in some of the whorls is different, the flower is anisomerous of unequal number.

The pistillate whorl is very liable to frequently happens that when it is fully formed, the number of its parts is not in conformity with that of the other such circumstances, however, a flower has been called symmetrical, provided the parts of the other whorls are normal, - the permanent state of the pistil not being taken into account in determining fig.

38 shows a pentamerous symmetrical flower, with dimerous pistil. Symmetry, then, in botanical language, has reference to a certain definite numerical relation of parts. A flower in which the parts are arranged in twos is called dimerous; when the parts of the whorls are three, four or five, the flower is trimerous, tetramerous or pentamerous, symmetry which is most commonly met with is trimerous and pentamerous - the former occurring generally among monocotyledons, the latter among and tetramerous symmetry occur also among dicotyledons.

article The various parts of the flower have a certain definite relation to the axis. 35, one sepal is next the axis, and is called superior or posterior; another is next the bract, and is inferior or anterior, and the other two are lateral; and certain terms are used to indicate that position. A plane passing through the anterior and posterior sepal and through the floral axis is termed the median plane of the flower; a plane cutting it at right angles, and passing through the lateral sepals, is the lateral plane; whilst the planes which bisect the ?.

11 4lll!0 FIG. - Diagrammatic section of a symmetrical pentamerous flower of Stone-crop Sedum, consisting of five sepals s, five petals p alternating with the sepals, ten stamens a in two rows, and five carpels c containing dark lines d on the outside of the carpels are glands. - Diagram of the flower of Flax Linum, consisting of five sepals s, five petals p, five stamens a, and five carpels c, each of which is flower delivery mount pleasant sc divided into dots represent a whorl of stamens which has is pentamerous, complete, symmetrical and regular.

article - Diagram of the symmetrical trimerous flower of Fritillary Fritillaria. - Diagram of the flower of Saxifrage Saxifraga tridactylites. The calyx and corolla consist of five parts, the stamens are ten in two rows, while the pistil has only two parts developed. angles formed by the lateral and median planes are the diagonal planes and in these flowers the petals which alternate with the sepals are cut by the diagonal planes. while the odd sepal is the order Scrophulariaceae one of the two carpels is posterior and the other anterior, whilst in Convolvulaceae the carpels are arranged the twisting of a part makes a change in the position of other parts, as in Orchids, where the twisting of the ovary changes the position of the labellum.

When the different members of each whorl are like in size and shape, the flower is said to be regular; while differences in the size and shape of the parts of a whorl make the flower irregular, as in the papilionaceous flower, represented in fig. When a flower can be divided by a single plane into two exactly similar parts, then it is said to be flowers free flower delivery in nyc Papilionaceae, Labiatae, are contrast with this are polysymmetrical or actinomorphic flowers, which have a radial symmetry and can be divided by several planes into several exactly similar portions; such are all regular, symmetrical the parts of any whorl are not equal to or some multiple of the others, then the flower 15 want of symmetry may be brought about in various in the symmetrical arrangement as well as in the completeness and regularity of flowers has been traced to suppression or the non-development of parts, degeneration or imperfect formation, cohesion or union of parts of the same whorl, adhesion or union of the parts of different whorls, multiplication of parts, and deduplication sometimes called chorisis or splitting of parts.

article Cohesion, or the union of parts of the same whorl, and adhesion, or the growing together of parts of different whorls, are causes of change both as regards form and in Cucurbita the stamens are originally five in number, but subsequently some cohere, so that three stamens only are seen in the mature is well seen in the gynostemium of orchids, where the stamens and stigmas Capparidaceae the calyx and petals occupy their usual position, but the axis is prolonged in the form of a gynophore, to which the stamens are united.

Day delivery discount flower same, or an increase of the number of parts, gives rise to have already alluded to the interposition of new members in a takes place chiefly in the staminal whorl, but usually the additional parts produced form a symmetrical whorl with the some instances, however, this is not the in the horse-chestnut there is an interposition of two stamens, and thus seven stamens are formed in the flower, which is asymmetrical.