Anther Sentence Examples
In these cases the anther is to a greater or less degree fixed.
Botanists were for a long time content to know that the scattering of the pollen from the anther, and its application to the stigma, were necessary for the production of perfect seed, but the stages of the process of fertilization remained unexplored.
When the pollen-grains are ripe, the anther dehisces and the pollen is shed.
They are attracted to the flower by its colour or its perfume; they seek, collect or feed on its honey, and while so doing they remove the pollen from the anther and convey it to another flower, there to germinate on the stigma when its tubes travel down the style to the ovary where their contents ultimately fuse with the "oosphere" or immature egg, which becomes in consequence fertilized, and forms a seed which afterwards develops into a new plant (see article Angiosperms).
The movements of the pollen-masses may readily be seen with the naked eye by thrusting the point of a needle into the base of the anther, when the disks adhere to the needle as they would do to the antenna of an insect, and may be withdrawn.Advertisement
From the base of the inner part of the tube of the flower, but quite free from it, uprises a cylindrical stalk surrounded below by a small cup-like outgrowth, and bearing above the middle a ring of five flat filaments each attached by a thread-like point to an anther.
Each cone consists of an axis, on which numerous broad and thin bracts are arranged in regular rows; in the axil of each bract occurs a single flower; a male flower is enclosed by two opposite pairs of leaves, forming a perianth surrounding a central sterile ovule encircled by a ring of stamens united below, but free distally as short filaments, each of which terminates in a trilocular anther.
In Scrophularia the fifth stamen appears as a scale-like body; in other Scrophulariaceae, as in Pentstemon, it assumes the form of a filament, with hairs at its apex in place of an anther.
Then the walls of the mother-cells are absorbed, and the pollengrains float freely in the fluid of the pollen-sacs, which gradually disappears, and the mature grains form a powdery mass within the anther.
In orchids each of the pollen-masses has a prolongation or stalk (caudicle) which adheres to a prolongation at the base of the anther (rostellum) by means of a viscid gland (retinaculum) which is either naked or covered.Advertisement
In Orchidaceae the stigma is situated on the anterior surface of the column beneath the anther.
One such yellow anther can be seen in the bottom right corner of the image below.
Mitochondrial biogenesis and function are of vital importance during anther development.
In flowering plants, anther s produce pollen which contains male gametes, and the embryo sac within the ovary contains a female gamete.
Under the microscope, an anther can be seen to have many spherical to ellipsoidal pollen grains on its surface.Advertisement
In some Guttiferae, as Hebradendron cambogioides (the Ceylon gamboge plant), the anther opens by a lid separating from the apex (circumscissile dehiscence) .
Anther popular option is cantaloupe or honeydew wedges wrapped with prosciutto.
Each has a small calyx in the form of a shallow rim, sometimes five-lobed or toothed; five petals, which cohere by their tips and form a cap or hood, which is pushed off when the stamens are ripe; and five free stamens, placed opposite the petals and springing from a fleshy ring or disk surrounding the ovary; each bears a twocelled anther.
The pollen is set free by the opening (dehiscence) of the anther, generally by means of longitudinal slits, but sometimes by pores, as in the heath family (Ericaceae), or by valves, as in the barberry.
The division between the lobes is marked on the face of the anther by a groove or furrow, and there is usually on the face a suture, indicating the line of dehiscence.Advertisement
This column stands up from the base of the flower, almost at right angles to the lip, and it bears at the top an anther, in the two hollow lobes of which are concealed the two pollen-masses, each with its caudicle terminating below in a roundish gland, concealed at first in the pouch-like rostellum at the front of the column.
In such cases the contact of an insect or other body with those processes is sufficient to liberate the pollen often with elastic force, even when the anther itself is not touched.
Older flower with the stamens (S) anther is developed o n the c orolla dried up.er(X2) dth e hairs before the filament, and when the latter is not produced, the anther is sessile, as in the mistletoe.
The anther entire (a) with its filament; section of anther (b) showing the four loculi.
The anther consists of lobes containing the minute powdery pollen grains, which, when mature, are discharged by a fissure or opening of some sort.Advertisement
The endothecium varies in thickness, generally becoming thinner towards the part where the anther opens, and there disappears entirely.
The walls of the cells are frequently absorbed, so that when the anther attains maturity the fibres are alone left, and these by their elasticity assist in discharging the pollen.
Sometimes, however, only two cavities remain in the anther, by union of the sacs in each lobe, in which case the anther is said to be bilocular or dithecal.
That part of the anther to which the filament is attached is the back, the opposite being the face.
When the filament is continuous with the connective, and is prolonged so that the anther-lobes appear to be united to it throughout their whole length, and lie in apposition to it and on both sides of it, the anther is said to be adnate or adherent; when the filament ends at the base of the anther, then the latter is innate or erect.
The pollen-grains or microspores contained in the anther consist of small cells, which are developed in the large thick-walled mother-cells formed in the interior of the pollen-sacs (microsporangia) of the young anther.
The object of these movements will be appreciated when it is remembered that, if the pollen-masses retained the original direction they had in the anther in which they were formed, they would, when transported by the insect to another flower, merely come in contact with the anther of that flower, where of course they would be of no use; but, owing to the divergences and flexions above alluded to, the pollen-masses come to be so placed that, when transplanted to another flower of the same species, they come in contact with the stigma and so effect the fertilization of that flower.
The Monandreae have been subdivided into twenty-eight tribes, the characters of which are based on the structure of the anther and pollinia, the nature of the inflorescence, whether terminal or lateral, the vernation of the leaf and the presence or absence of a joint between blade and sheath, and the nature of the stem.
The perianth consists of five or six oblong greenish lobes, within which is found a tuft, consisting of a large number of stamens, each of which has a very short filament and an oblong two-lobed anther bursting longitudinally, and surmounted by an oblong lobe, which is the projecting end of the connective.
Many plants produce, in addition to ordinary open flowers, so-called cleistogamous flowers, which remain permanently closed but which notwithstanding produce fruit; in these the corolla is inconspicuous or absent and the pollen grows from the anther on to the stigma of the same flower.
The anther is developed before the filament, and is always sessile in the first instance, and sometimes continues so.
Sometimes the anther has a single cavity, and becomes unilocular, or monothecal, or dimidiate, either by the disappearance of the partition between the two lobes, or by the abortion of one of its lobes, as in Styphelia laeta and Althaea officinalis (hollyhock).
Occasionally there are numerous cavities in the anther, as in Viscum and Rafesia.
Below the anther the surface of the column in front is hollowed out into a greenish depression covered with viscid fluid - this is the two united stigmas.
Even in homogamous flowers cross-pollination is in a large proportion of cases the effective method, at any rate at first, owing to the relative position of anther and stigma or the fact that the plant is self-sterile.
Thus in Dicentra and Corydalis there are six stamens in two bundles; the central one of each bundle alone is perfect, the lateral ones have each only half an anther, and are really stipules formed from the staminal leaf.
When the anther lobes are rendered horizontal by the enlargement of the connective, then what is really longitudinal dehiscence may appear to be transverse.