* Pint's sylvestris - Plate 19 C.
Separated by some botanists from the great group of Monocotyledons, with which they are associated by others, is a small intermediate group, called Dictyogens, the peculiar features of which are, that they combine with the floral structure of Endogens (Monocotyledons) the netted venation and woody structure of Exogens (Dicotyledons). Of this group we have two illustrations.
First, of the family of Dioscoreaceous plants, which contains the Yam, we have a native species, the Black Bryony,* which bears very much the general aspect of the plants of this family. This Black Bryony, like the cultivated Yams, has thick tuberous root-stocks, and rather slender stems, which twine over hedges and bushes to a considerable extent, in many parts of the country. It is rather an elegant plant in its general aspect, though wanting in beauty of inflorescence. The stems are quite smooth, and furnished with alternate glossy bright green leaves of a heart-shaped figure, tapering to a slender point, and attached by longish stalks. These leaves are traversed by a few longitudinal strongly-marked ribs, between which they are occupied by a network of smaller veins. The plant is dioecious, that is, it bears only staminiferous flowers on one plant, and pistilliferous or fertile ones on another. The former grow in long slender racemes, which are often branched and longer than the leaves; they are individually small, consisting of a perianth of six small green segments, and six stamens - quite inconspicuous. The latter, which are equally wanting in attractiveness, and are even less striking on account of their growing in much shorter and less elegant racemes, consist of six segments and a three-branched style, the ovary being inferior; these however are succeeded by bright scarlet berries of globular form.
* Tamus communis - Plate 19 D.
Another Dictyogen is found in the Herb-Paris,* which belongs to the Trilliaceous family, - though this is by some botanists regarded as a section only of the Liliaceous Order. It is a dwarf herb with a creeping rootstock, producing a simple erect stem, six to nine inches or rarely somewhat more in height, furnished with a few scales at the base, but otherwise naked to the top, where grows a whorl of broadly ovate or obovate leaves, two to three inches long, strongly marked with a few longitudinal ribs, and netted between them with finely reticulated veins. In the centre of this guard of leaves stands a single erect flower on a stalk of moderate length, and consisting of a perianth of eight segments, of a yellowish-green colour, the outer series narrow-lanceolate and much broader than the inner ones, which are quite linear; within this eight erect stamens, which are awl-shaped, with the anther-cells affixed one on each side near the middle. The ovary is superior, four-celled, with four styles, and becomes a succulent bluish-black berry. The name Paris is said to come from par, parts, equal, in allusion to the regularity of numbers occurring in the parts - four leaves, four sepaline and four petaline divisions, twice four stamens, four styles, and a four-celled ovary, - which latter becomes a lurid-purple berry, whence rustics give the plant the name of One-berry, or True-Love.
We must now select a few illustrations from the different families of Monocotyledons, commencing with those in which the sexes are separated.
Of this group, the Common Frog-bit,† itself the type of the Hydrocharidaceous family, furnishes an illustration. This is a pretty water plant, with rather slender stems, producing here and there tufts of floating leaves and submerged roots.
* Paris quadrifolia - Plate 20 A.
† Hydrocharis Morsus-ranae- - Plate 20 B.
The leaves are roundish, entire, somewhat fleshy, smooth, and lie flat on the water. The flowers rise up amongst and above the leaves, and consist of three small outer green segments, representing a calyx, and three larger inner white ones representing the petals of a corolla, and large enough to give the plant a rather attractive character, being produced freely on the surface of ponds and ditches. In the staminate flowers, a variable number of stamens, from three to twelve, is produced; while in the female flowers, which have an inferior ovary, there are six styles with two-cleft stigmas. The flowers issue from spathes formed of two thin bracts, those of the male plants being shortly stalked, and those of the females sessile among the leaves; in the latter the pedicel is enlarged at the top into a sort of tube to the perianth, enclosing the ovary, which becomes a dry six-celled fruit, containing several seeds. Mr. Lees has observed of this common water-plant: "The economy of this almost unregarded tenant of the water is not unworthy of notice, nor when closely examined is it devoid of beauty. Its floating reniform leaves are purple beneath, and it increases almost entirely by floating runners, so that small retired pools are sometimes entirely covered with the thick-set foliage, affording an impervious retreat to thousands of Lymneae and aquatic insects. The stainless flowers are of so delicate a structure that they are injured by contact with the water, and instead therefore of floating on its surface, they are providently provided with elevating stalks, around whose basis is a pellucid protecting bract. About wild commons and shady untrodden lanes, little shield-like pools often appear, whose waters are entirely hidden, roofed over, with a verdant covering of the Hydrocharis, and scattered about this emerald table appear the numerous white and delicate tripetaled blossoms, as if Titania and her fairy court had there prepared a picnic banquet in the shadowy retreat. On such a picture I have gazed in the silence of a summer's evening, when, as these silvery flowers are long conspicuous in the twilight, the splendour of the broad rising moon has increased and harmonized the illusion of the scene."