The stamens and the pistil are sometimes spoken of as the essential organs of the flower, as the presence of both is required in order that perfect seed may be with few exceptions the stamen represents a leaf which has been specially developed to bear the pollen or microspores, it is spoken of in comparative morphology as a microsporophyll; similarly the carpels which make up the pistil are the megasporophylls see Angiosperms.

Hermaphrodite or bisexual flowers are those in which both these organs are found; unisexual or diclinous are those in which only one of these organs appears, - those bearing stamens only, being staminiferous or " male "; those having flower delivery bethlehem easton pa pistil only, pistilliferous or " female.

Other plants are timorphic, as species of Lythrum, and proper fertilization is only effected by combination of parts of equal some plants the stamens are perfected before the pistil; these are called proterandrous, as in Ranunculus repens, Silene maritima, Zea other plants, but more rarely, the pistil is perfected before the stamens, as in Potentilla argentea, Plantago flower delivery bethlehem easton pa, Coix Lachryma, and they are termed in which proterandry or proterogyny occurs are called in the same plant there are unisexual flowers, both male and female, the plant is said to be nionoecious, as in the hazel and castor-oil the male and female flowers of a species are found on separate flower delivery bethlehem easton pa, the term dioecious is applied, as in Mercurialis and hemp; and when a species has male, female and hermaphrodite flowers on the same or different plants, as in Parietaria, it is polygamous.

The stamens arise from the thalamus or torus within the petals, with which they generally alternate, forming one or more whorls, which collectively constitute the androecium. Their normal position is below the pistil, and when they are so placed fig. 64, a upon the thalamus they are they become adherent to the petals, or are epipetalous, and the insertion of both is looked upon as similar, so that they are still hypogynous, provided they are independent of the calyx and the other cases they are perigynous or epigynous fig.

Numerous intermediate forms occur, especially amongst Saxifragaceae, where the parts are half superior or half the stamens become adherent to the pistil so as to form a column, the flowers are said to be gynandrous, as in Aristolochia fig. article These arrangements of parts are of great importance in stamens vary in number from one to many acyclic flowers there is often a gradual transition from petals to stamens, as in the white water-lily fig.

When flowers become double by cultivation, the stamens are converted into petals, as in the paeony, camellia, rose, c. When there is only one whorl the stamens are usually equal in number to the flower delivery bethlehem easton pa or petals, and are arranged opposite to the former, and alternate with the flower is then the stamens are not equal in number to the sepals or petals, the flower is there is more than one whorl of stamens, then the parts of each successive whorl alternate with those of the whorl preceding it.

The staminal row is more liable to multiplication of parts than the outer whorls. A flower with a single row of stamens is the flowers delivery las vegas are double the sepals or petals as regards number, the flower flower delivery bethlehem easton pa diplostemonous; if more than double, additional rows of FIG.

- Flower of cowslip Primula veris cut vertically. s, Sepals joined to form a gamosepalous calyx; c, corolla consisting of tube and flower delivery bethlehem easton pa limb; a, stamens springing from the mouth of the tube; p, pistil.

article - Irregular gamopetalous labiate corolla of the Dead-nettle Lamium album. The upper lip u is composed of two petals united, the lower lip 1 of the two lips there is a throat is the part where the tube and the labiate limb the arching of the upper lip this corolla is called ringent.

- Irregular gamopetalous ligulate flower of Ragwort Senecio. - Flower of Paeonia peregrina,in longitudinal section. stamens may be developed in the usual centripetal acropetal order, as in Rhamnaceae; or they may be interposed between the pre-existing ones or be placed outside them, i. develop centrifugally basipetally, as in geranium and oxalis, when the flower is said to be obdiplostemonous. When the stamens are fewer than twenty they are said to be flower delivery bethlehem easton pa when above twenty they are indefinite, and are represented by the flower delivery bethlehem easton pa 00.

The number of stamens is indicated by the Greek numerals prefixed to the term androus; thus a flower with one stamen is monandrous, with two, three, four, five, six or many stamens, di- tri- tetr- pent- hexor polyandrous, respectively.

article The function of the stamen is the development and distribution of the stamen usually consists of two parts, a contracted portion, often thread-like, termed the filament fig. 25 f, and a broader portion, usually of two lobes, termed the anther flower delivery bethlehem easton pa, containing the powdery pollen p, and supported upon the end of the portion of the filament in contact with the anther-lobes is termed the the FIG.

c, Calyx; p, petal; e, stamen; s, calyx, petals and stamens spring from above the ovary o in which two chambers are shown each with a pendulous ovule; d, disc between the stamens and Strasburgers Lehrbuch mission of Gustav Fischer. - Flowers of Aristolochia Clem- atitis cut through longitudinally.

Young stamen is abortive, flower in which the stigma N is receptive and cannot perform and the stamens 3 have not yet opened; its II. Older flower with the stamens S anther is developed o n the c orolla dried up. erX2 dth e hairs before the filament, and when the latter is not produced, the anther is sessile, flower delivery bethlehem easton pa in the mistletoe.

article The filament is usually, as its name imports, filiform or threadlike, and cylindrical, or slightly tapering towards its is often, however, thickened, compressed and flattened in various ways, becoming petaloid in Canna, Marania, water-lily fig.

32; subulate or slightly broadened at the base and drawn out into a point like an awl, as in Butomus umbellatus; or clavate, that is, narrow below and broad flower delivery bethlehem easton pa, as in Thalictrum. In some instances, as in Tamarix gallica, Peganum Harmala, and Campanula, the base of the filament is much dilated, and ends suddenly in a narrow thread-like these cases the base may flower delivery bethlehem easton pa off lateral stipulary processes, as in Allium and Alyssum filament varies much in length and in length sometimes bears a relation to that of the pistil, and to the position of the flower, whether erect or filament is usually of sufficient solidity to support the anther in an erect position; but sometimes, as in grasses, and other wind-pollinated flowers, it is very delicate and hair-like, so that the anther is pendulous fig.

The filament is generally continuous from one end to the other, but in some cases it is bent or jointed, becoming geniculate; at other times, as in the pellitory, it is is colourless, or of different in fuchsia and Poinciana, it is red; in Adamia and Tradescantia virginica, blue; in Oenothera and Ranunculus acrisyellow.

article Hairs, scales, teeth or processes of different kinds are some times developed on the spiderwort Tradescantia virginica the hairs are beautifully coloured, moniliform or necklace-like, and afford good objects for studying rotation of the are usually articulated to the thalamus or torus, and the stamens fall off after fertilization but in Campanula and some other plants they are continuous with the torus, and the stamens remain persistent, although in a withered are produced in the whorl of stamens by cohesion of the filaments to a greater or less extent, while the anthers remain free; thus, all the filaments of the androecium may unite, forming a tube round the pistil, or a central bundle when the pistil is abortive, the stamens becoming monadelphous, as occurs in plants of the Mallow tribe; or they may be arranged in two bundles, the stamens being diadelphous, as in Polygala, Fumaria and Pea; in this case the bundles may be equal or frequently happens, especially in Papilionaceous flowers, that out of ten stamens nine are united by their filaments, while one the postericr one is free fig.

When there are three or more bundles the stamens are triadelphous, as in Hypericum aegyptiacum, or polyadelphous, as in Ricinus communis castor-oil.