STAIRENS are those parts in the flowers of phanerogamous plants which excite the pistil to the formation of the fruit, and thus effect fertilization or fecundation (q.v.). A stamen consists of a receptacle—the anther ; which contains a dust—the pollen—various in color, but generally yellow, and is generally supported on a stalk called the filament ; the anther being the blade of a metamorphosed leaf. and the filament the leaf-stalk. The filament is, however, sometimes wanting, and the anther is .then said to"":" be sessile. Each anther generally consists of two cells, forming two lobes, which, before they open to give forth the pollen, are again divided- into two cell-like parts, and at the time of their maturity open by longitudinal clefts, by pores, or by valves, to scatter the pollen, which is conveyed to the stigma either by its own falling, by the wind, or by the insects which seek honey in flowers. See PISTIL. The pollen consists of single cells, whiith arc usually free; more rarely, the pollen of each cell is united into a mass, called the pollen-mass or pollintem, as iii the Orel idea and Asclepia dacetv. The stamens are either found along with the pistil in the sametlower,• and then arranged around it, in which case the flower is hermaphrodite ; or they are placed by themselves in separate flowers, which are therefore called male flowers. the starlit zit are sometimes united together, generally b' the filaments, which form a tube, and the flower is monadelpIams ; sometimes, by their union, they form two sets. when the flower is diadelphous ; sometimes three or more, when it is polyadelphoas ; and the filaments are sometimes united with the pistil into a column, from which the anthers spring, as if they grew from the pistil, when the flower is gynandraus. See BOTANY. The stamens form either one or more whorls, and when in one whorl are either opposite to the petals or alternate with them. The latter is regarded as their normal position. Sometimes, by abortion, there is only one stamen. Being leaf-organs, stamens arise from the 21X1;;; hut
they very frequently grow upon the corolla, so that they seem to derive their origin from it. When the stamens seem to arise from the corolla or from the calyx, they, and also the flower, are said to be perigynous (Gr. pert, around, and gyne, a wife); when they grow from the pistil, they are epigynous (Gr. epi, upon); and when from beneath it, hypogynous (Gr. hypo, under). These distinctions have been much made 1.1-e of, by Jussieu and others, in classification. The transitions of petals into stamens can be easily traced in some flowers, for example, in the water lily. In double flowers, the stamens have been changed into petals. Umlauts adopted the stamens as the means of his divi sion of plants classes (see Bo rANY); but in so far as the classification was founded on their mere number, it was artificial, the number of stamens being various in plants very closely allied. Stamens are among the organs of plants which most frequently dis play irritability (q. v.).
Thu filament assumes a great variety of forms. Sometimes it is short and thick, sometimes long and slender; sometimes dilated at the base; sometimes petal-like, with the stamen at its tip; sometimes forked, or divided into three teeth, of which the central one hears the anther; sometimes bent or jointed, sometimes spiral. The form of the anther varies still more than that of the filament; indeed, the variety of forms is endless. The connective is a body which unites the lobes of the anther. When the filament is con tinuous with the connective, the anther-lobes seeming to be united to it through their whole length, the anther is said to be adnate or adherent ; when the filament ends at the base of the anther. the anther is mate or erect. In many flowers, as in those of grasses, the anther is attached to the filament, by a mere point, and is very movable, easily turned by the wind. It is then said to be versatile.