Page:Illustrations of Indian Botany, Vol. 2.djvu/182

 88

ILLUSTRATIONS OF INDIAN BOTANY.

or several series. Corolla monopetalous, inserted on the top of the calyx tube, neurumphi- petalous, that is, the petals are furnished on the margins with nerves, whence there usually appear only 5 nerves in the tube (two and two united), extending from the base to the divisions, and ten in the limb, one on each margin of each lobe ; to these are sometimes added, but very rarely visible, accessory nerves occupying the middle of the petals. The length of the tube from the base to the point of apparent attachment of the filaments is various. The throat is often dilated from the insertion of the filaments to the lobes : the lobes are usually 5, more rarely 4, 3, or 2, valvate in aestivation ; sometimes they are all equal, sometimes more or less unequal or irregular, or palmated, or two-lipped (the outer lip formed by the cohesion of 3 lobes, and the inner of 2 ; or the outer of 4 and the inner of 1, sometimes divided by a single fissure on the interior side, and then all are united into a single, flat, 5-toothed, strap-like petal. Stamens 5, rarely 4, wanting, or rudimentary, in female or sterile flowers : filaments alternate with the lobes of the corolla and therefore congruent with the nerves of the tube ; attached to the tube of the corolla and free above ; either altogether distinct or united into a tube (monadelphous), jointed near the apex, the upper joint antheriferous and occupying the place of a connective. Anthers erect, united into a tube round the style, ( Syngenesia of Synantherea J, linear, 2-celled, opening within by a longitudinal slit, 4-valved ; valves bent outwards (extroflexis) terminating in an appendix or wing, varying in different plants in the size and shape, often differing in consistence from the polleniferous portion : the base often lengthened into two tails, varying in length and shape. Pollen globose, or elliptic, echinulate or smooth. Ovary of one carpel, adhering to the calyx, with 1 ovule. Style terete or rarely thickened at the base (bulbosus), in male flowers, when present, often most simple ; in female and hermaphrodite ones two-cleft ; the branches (commonly called stigmas) flat above, convex below, sometimes altogether free, sometimes more or less united. Stigmatic glands, or true stigmas, in a double row, seated on the upper surface of the branches of the style, the rows continuous, marginal, roughish, more or less prominent or distinct. The upper parts of the style, of hermaphrodite flowers, furnished with rigid pollen-col- lecting hairs, seated either on the apex of the branches, or on their lower side; which are wanting in female or neuter flowers.

The fruit, or achaenium, consists of the calyx tube, with the pericarp and seed coat more or less intimately united between themselves, and enclosing the embryo. The fruit is therefore 1-celled and 1-seeded, articulated with the receptacle, usually sessile, but some- times stipitate, furnished at the base with a basilar or lateral areola ; erostrate or beaked at the apex, surmounted by the pappus, terminated by an epigynous disk embracing a styliform or hollow central nectarium, continuous with the ovary. Seed erect, attached to the bottom of the fruit by a very short funiculus. Interior lamina of the seed coat Endopleura (albumen of Lessing), thickish, soft, diaphanous, perforated by the diaphanous funiculus. Embryo straight, radicle short, straight; cotyledons flat, often somewhat con- vex on the back, rarely curved, occasionally, by accident, three.

Inflorescence. Flowers collected into a capitulus, or glomerulus (the old com- pound flower). A Capitulum consists of a number of flowers, attached to a receptacle, or apex of a branch (a condensed spike), sometimes flat, sometimes conical, or elongated, the exterior or lower ones opening first. Flowers either all hermaphrodite, the capitulus is then Homogamous ; or the exterior ones are female or neuter, the interior ones hermaphrodite, Heterogamous ; or all, on the same plant, are either male or female, the capitula are then Monoicous ; sometimes they are Heterocephalous, that is, in the same plant some are male some female; sometimes they are Dioicous, that is, the capitula of the plant are either all male or all female. Some capitula have all the flowers tubular, and are then discoid or flosculose, or they are all strap-shaped, and are then called Ligulatce or Semiflosculosce, or sometimes the flowers of the margin or ray are ligulate, and those of the centre or disk tubulai*, when they are called radiate. Sometimes all are bilabiate and are then falsely-discoid or radiatiform. Discoid and falsely-discoid capitula sometimes have the marginal flowers like, but larger than the centre ones, and are then said to be crowned.

The Involucrum, formerly called common calyx, consists of a number of leaves or