At the base of the ovarium of Cyperaceæ are often found little filiform appendages, called hypogynous sete by most botanists. These are probably of the nature of the squamulæ of Grasses, and have been named perisporum by some French writers.

Bractea are generally distinct from each other, and imbricated or alternate. Nevertheless, there are some striking exceptions to this; as remarkable instances of which may be cited Althea and Lavatera among Malvaceæ, all Dipsaceæ, and some Trifolia, particularly my Tr. cyathiferum (Hooker, Fl. Boreali-Amer.), in all which the bractea are accurately verticillate, and their margins confluent, as in a true calyx. 4. Of the Flower.

The Flower is a terminal bud enclosing the organs of reproduction by seed. By the ancients the term flower was restricted to what is now called the corolla; but Linnæus wisely extended its application to the union of all the organs which contribute to the process of fecundation. The flower, therefore, as now understood, comprehends the calyx, the corolla, the stamens, and the pistillum, of which the two last only are indispensable. The calyx and corolla may be wanting, and a flower will nevertheless exist; but if neither stamens nor pistillum nor their rudiments are to be found, no assemblage of leaves, whatever may be their form or colour, or how much soever they may resemble the calyx and corolla, can constitute a flower.

The flower, when in the state of a bud, is called the alabastrus (bouton of the French), a name used by Pliny for the rose-bud. Some writers say alabastrum, forgetting, as it would seem, that that term was used by the Romans for a scent-box, and not for the bud of a flower. Link calls the parts of a flower generally, whether united or connate, moria, whence a flower is bi-polymorious (Elem., 243.); but I know of no writer who employs these terms, which indeed are quite superfluous.

The flowers of an anthodium, which are small, and somewhat different in structure from ordinary flowers, are called florets (flosculi; elytriculi of Necker; fleuron of the French).

The period of opening of a flower is called its anthesis; the manner in which its parts are arranged with respect to each other before opening is called the aestivation. Estivation is the same to a flower-bud as vernation (p. 53.) is to a leafbud: the terms expressive of its modifications are to be sought in Glossology. This term æstivation is applied separately to the parts of which a flower may consist; thus, we speak of the æstivation of the calyx, of the corolla, of the stamens, and of the pistillum; but never of the aestivation of a flower, collectively.

5. Of the Inflorescence.

Inflorescence is a term contrived to express generally the arrangement of flowers upon a branch or stem. The part which immediately bears the flowers is called the pedunculus or peduncle, and is to be distinguished from any portion of a branch by not producing perfect leaves; those which are found upon it called bractea being much reduced in size and figure from what are borne by the rest of the plant.

The term peduncle, although it may be understood to apply to all the parts of the inflorescence that bear the flowers, is only made use of practically, to denote the immediate support of a single solitary flower, and is therefore confined to that part of the inflorescence which first proceeds from the stem. If it is divided, its principal divisions are called branches; and its ultimate ramifications, which bear the flowers, are named pedicels. There are also other names which are applied to modifications of the peduncle.

In plants which are destitute of stem, it often rises above the ground, supporting the flowers on its apex, as in the Cowslip. Such a peduncle is named a scape (hampe, Fr.). Some botanists distinguish from the scape the pedunculus radicalis, confining the former term to the peduncle which arises from the central bud of the plant, as in the Hyacinth; and applying the latter to a peduncle proceeding from a lateral bud, as in Plantago media.

When a peduncle proceeds in a nearly right line from the base to the apex of the inflorescence, it is called the rachis, or the axis of the inflorescence. This latter term was used by Palisot de Beauvois to express the rachis of Grasses, and is perhaps the better term of the two, especially as the term rachis is applied by Willdenow and others, without much necessity it must be confessed, to the petiole and costa of Ferns. In the locustæ of Grasses the rachis has an unusual toothed flexuose appearance, and has received the name of scobina from M. Dumortier. If it is reduced to a mere bristle, as in some of the single-flowered locustæ, the same writer then distinguishes it by the name of acicula. I mention these and similar terms, in order that nothing which can even remotely lead to information may be omitted; but I cannot recommend their adoption.

When the part which bears the flowers is repressed in its developement, so that, instead of being elongated into a rachis, it forms a flattened area on which the flowers are arranged, as in Compositæ, it becomes what is called a receptacle; or, in the language of some botanists, the receptacle of the flower (fig. 72.).

When the receptacle is not fleshy, but is surrounded by an involucrum, it is called the clinanthium (the thalamus of Tournefort), as in Compositæ, or, in the language of M. Richard, phoranthium; the former term is that generally adopted. But if the receptacle is fleshy, and is not enclosed within an involucrum, as in Dorstenia and Ficus (fig. 73.), it is then called by Link Hypanthodium; the same writer formerly named it Amphanthium, a term now abandoned.

According to the different modes in which the inflorescence is arranged, it has received different names, the right application of which is of the first importance in descriptive botany. If flowers are sessile along a common axis, as in Plantago, the inflorescence is called a spike (épi, Fr.), (fig. 76.); if they are pedicellate, under the same circumstances, they form a raceme (grappe, Fr.), (fig. 77.) as in the Hyacinth: the raceme and the spike differ, therefore, in nothing, except that the flowers of the latter are sessile, of the former pedicellate. These are the true characters of the raceme and spike, which have been confused and misunderstood in a most extraordinary manner by some French writers.

When the flowers of a spike are destitute of calyx and corolla, the place of which is taken by bracteæ, and when with such a formation the whole inflorescence falls off in a single piece, either after flowering or ripening the fruit, as in Corylus, Salix, &c., such an inflorescence is called an amentum or catkin (chaton, Fr.; Catulus, Iulus, nucamentum, of old writers), (fig. 81.) Linnæus considered the catkin to be an elongated filiform receptacle, analogous to that of Compositæ, in which he is followed by Sir James Edward Smith, Link, and others. This opinion arises from a distinction being drawn between the axis of a spike and the receptacle of Composite; but, as I have already stated, the latter can be considered in no other light than that of a depressed axis or rachis: so that, when the amentum is said not to be a true axis, but an elongated receptacle, a difference is drawn between words rather than things; for if a receptacle is only a depressed axis, an elongated receptacle is necessarily a return to the common form of the axis.

If a spike consists of flowers destitute of calyx and corolla, the place of which is occupied by bractea, supported by other bractea which enclose no flowers, and when with such a formation the rachis, which is flexuose and toothed, does not fall off with the flowers, as in Grasses, each part of the inflorescence so arranged is called a spicula or locusta (épillet, Dec.; paquet, Tournefort). Link is of opinion that the rachis of a spicula, as well as that of the amentum, is a kind of receptacle.