Loudon's encyclopædia of plants : comprising the specific character, description, culture, history, application in the arts, and every other desirable particular respecting all the plants indigenous to, cultivated in, or introduced to Britain / [J.C. Loudon].

  • Loudon, J. C. (John Claudius), 1783-1843.
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: Loudon's encyclopædia of plants : comprising the specific character, description, culture, history, application in the arts, and every other desirable particular respecting all the plants indigenous to, cultivated in, or introduced to Britain / [J.C. Loudon]. Source: Wellcome Collection.

    778/1618 (page 748)
    Class XX. — GYNANDRIA. The singular plants which constitute this class are distinguished from all others by the anomalous structure of their (lowers. These do not, as is usually the case, contain a certain number of stamens surrounding a central ovarium or style, but on the contrary are furnished with a solitary fleshy undivided process, round which the sepals radiate, and which supplies the place of stamens and style. The nature of this process has been variously explained : the modern opinion is that it is formed by the accretion of the stamens and style into a single mass, and this opinion seems to be confirmed by analysis and analogy. Omitting, therefore, a notice of such theories respecting its nature as are opposed to that which is now received as the most correct, it will suffice to explain a little in detail, the opinion which is adopted in this work. The central process, called the columna or column, is understood to be formed by the filaments of three stamens surrounding a style, and by mutual accretion firmly united with it and with each other into a solid mass. Of these three stamens, it mo3t frequently happens that the two lateral are sterile, and not furnished with even the vestige of an anthera; and that their presence is not indicated by more than two irregular excrescences, as in Orchis, or by the same number of small appendages, as in Satyrium, or by two horn-like or tooth-like processes, present in several of the genera with waxy pollen-masses : it even happens, and not unfrequently, that no vestige whatever of them remains. But in Cypripedium both are fertile and bear perfect anthers, while the central stamen is bar- ren and foliaceous. When the lateral stamens are, as above stated, abortive, which is the most common form of the columna, the central stamen bears at its upper extremity an anther, which is either moveable or fixed firmly in its place. The pollen which this contains, assumes three very distinct appearances in different tribes. It is either granular, dividing into many separable small pieces, as in Orchis ; or powdery, consisting of an infinite number of granules, as in Spiranthes ; or waxy, when it consists of a few large concrete masses, as in Epidendrum. The stigma is most frequently concave, and placed nearly under the anther, but in such a manner, that there is no contact between it and the pollen. In what way, therefore, fecundation can take piace among truly Gynandrous plants, is one of those mysterious contrivances of nature which has not yet been explained. It is generally believed to take place by absorption in some undiscovered manner, before the flowers expand; but it is extremely difficult to understand how this can occur in many genera. The foregoing remarks apply only to the tribe of plants called Orchideous. The few genera attached to the latter part of the class are Gynandrous by the cohesion indeed of their stamens and style, but in a much more obvious manner. Gynandrous plants are among the most interesting of the vegetable productions of the globe, whether we consider the vivacity of their colors, or the singularity of their organization, or the grotesque appearance of their tortuous roots, or the delicious perfume of their flowers. They are distributed in abundance over all the earth. In Europe and the temperate parts of the world, they are principally found in meadows and pastures among grass ; but in tropical regions tney often constitute the chief beauty of the forest, occupying the forked branches of living trees, or the prostrate trunks of fallen timber, over which, in company with ferns and parasi- tical Aroideas, they climb and trail in every direction, until they adorn the one with bright hues and rich odours foreign to their nature, and render the others more beautiful in death, than in the full vigour of their existence. Order 1. MONANDRIA. Stamen 1. ^ 1. Anther terminal, erect. Pollen granular, cohering by an elastic thread. 1855. Disa. Flowers ringent: helmet with a spur or bag at the base. Inner sepals united to the column. Lip without a spur. 185G. Satyrium. Flower ringent: five anterior sepals united at base. Lip behind, fornicate with two spurs or bags at the base. Anther resupinate. Stigma 2-lipped. 1857. Platanthera. Flower vaulted. Lip entire with a spur. Cells of the anther widely divided at their base by the broad interposed stigma. Glands of pollen masses naked. Lips of stigma absent. 1858. Gymnadenia. Cor. ringent. Lip spurred at the base beneath. Glands of the stalks of the pollen- mass naked, approximate. 1859. Orchis. Cor. ringent. Lip spurred on the underside at the base. Glands of the stalks of the pollen- mass (1-2) contained in one common little pouch. 1860. Nigritella. Ovary straight. Flower spreading. Lip posterior, entire, with a scrotiform spur. Glands of pollen-masses distinct, and enclosed in a single 2-celled pouch. 1861. Habenaria. Cor. ringent. Lip spurred on the upper side at the base beneath. Glands of the stalk of the pollen-mass naked, distinct, with the cells of the footstalks adnate or separated. 1862. Bartholina. Flower ringent: inner sepals united below with the lip. Lip spurred beneath at the base. Stalks of the pollen-masses long; cells united to the column : glands distinct, half covered by the exterior lobe. 1863. Glossula. Sepals conniving in a galea: the upper without a spur. Lip anterior, spurred, 3-parted, with an inflated spur. Pollen-masses 2, 2-parted, with 2 glands inclosed in distinct pouches. 1861. Anacamptis. The flower of Orchis, from which it differs in having the gland of the pollen-masses single, with indexed edges, and enclosed in a pouch. 1865. Aceras. Flower ringent. Lip without a spur. Glands of the pollen-masses included in a common pouch. 1866. Ophrys. Flower somewhat spreading. Lip without a spur. Glands of the pollen-masses inclosed in two distinct pouches. 1867. Chamorchis. Ovary reclinate at end. Flower galeate. Lip without a spur, undividea. Glands of the pollen-masses naked. Upper lip of stigma divided. Anther of Orchis. 1868. Herminium. Flower somewhat spreading. Lip without a spur. Glands of the pollen-masses naked, distinct. 1869. Serapias. Flower ringent. Lip without a spur. Column sharp-pointed. Pollen-masses attached to a single gland inclosed in one pouch. \ 2. Anther parallel with stigma. Pollen powdery. 1870. Goodyera. Cor. ringent, with the 2 exterior or lateral segments of the perianth placed beneath the lip, which is gibbous at the base and undivided at the extremity. Column free. Pollen angular. 1871. Diuris. Flower irregular. Two outer linear sepals placed beneath the trifid lip : the inner clawed and spreading. Column with the lateral lobes petaloid. Pollen farinaceous. 1872. Ponthieva. Flower irregular. Lip behind, with the inner sepals inserted in the column. Pollen farinaceous.