Fig. 30.—Flower and fruit of the Hawthorn. number of styles varies in the many different species included in the genus from one to five. The corolla, calyx, and stamens are the same as in the other genera included in this tribe, but the petals (b) are rounder and rather more indented. The seeds vary from one to five, each being enclosed in a bony covering, or stone, the whole being surrounded by the fleshy part of the calyx, which forms the eatable part of the Haw. In some of the species the haws are so large as to appear like little apples; but they may be always easily distinguished by the ripe ovary, or case which incloses the seed, being bony; whereas in all the varieties of Pyrus, the outer part of the ovary is cartilaginous, like the core of the apple. The seeds of the Hawthorn are a long time before they come up, from the hardness of this bony covering, which does not open naturally when ripe. The species composing the genus Raphiolepis, the Indian Hawthorn, have been separated from Cratægus; chiefly on account of the covering which encloses the seeds being of a paper-like texture, instead of bony, and each cell containing two seeds. The limb of the calyx also falls off before the fruit is ripe, instead of remaining on to form what is called an eye, as it does in the common Hawthorn. The leaves of the plants belonging to this genus vary in the different species; but those of the common Hawthorn are wedge-shaped, and cut deeply into three or five lobes.
The different species which compose the genus Cratægus were formerly considered to belong to the genus Mespilus. This genus, which is now almost confined to the common Medlar (Mespilus germanica), agrees with Cratægus in having each seed enclosed in a bony covering, but it differs in the limb of the calyx being in large leafy segments; and in the disk being very large and visible even when the fruit is ripe, from the tubular part of the calyx not closing over it.
Among the plants formerly included in the genus Mespilus, may be mentioned Photinia serrulata, and Eriobotrya japonica, both natives of Japan. The first of these was once called Cratægus glabra, and it is remarkable for its beautiful glossy leaves, which are of a deep green when old, and beautifully tinged with red when young; the flowers are white, and they are produced in what botanists call corymbose panicles. There are some other species of the genus Photinia, but only two or three are common in British gardens. Eriobotrya japonica, the Loquat-tree, was formerly called Mespilus japonica. It is remarkable for its large and handsome leaves, which are woolly on the under side. The flowers, which are small and white, are produced in large panicles, and they are followed by large pendulous bunches of the yellow pear-shaped fruit, which is covered with a woolly substance, and hence the botanic name Eriobotrya, which signifies woolly grapes. The tree will stand out in the open air in England, and it will flower freely in a greenhouse, but it requires a stove to ripen its fruit.
Cotoneaster and Amelanchier were also formerly included in Mespilus, and they are very closely allied to Photinia and Eriobotrya. The species belonging to Photinia, however, are easily known by their shining leaves, and the petals of their flowers being reflexed, that is, curved back; and the species of Eriobotrya are distinguished by their woolliness, which spreads over even the flowers and fruit. The Cotoneasters are known by the small petals of their flowers, which curve inwards, and remain a long time without falling. The leaves are also thick, and woolly or clothed with rusty hair on the under side; and the flowers, which are produced in cymes or panicles, with woolly pedicels, are followed by bright red haws, resembling those of the hawthorn. Lastly, the genus Amelanchier is known by its long narrow petals, and its ovary having five or ten cells, with five styles united at the base.
TRIBE VI.—SANGUISORBEÆ.
The plants included in this tribe agree more or less with the common Burnet (Sanguisorba officinalis). This plant, which is found in great abundance in rich meadows on calcareous soils, has its flowers produced in a close terminal spike. The flowers have no petals, but the calyx, which is four-cleft, is pink, and there are four glossy brown bracts to each flower; so that, on the whole, the flowers are rather ornamental, notwithstanding their want of petals. There are only four stamens, and two carpels with slender styles and pointed stigmas. The leaves are pinnate, consisting generally of nine leaflets, and each pair of leaflets is furnished with two stipules. The Alchemilla, or Ladies’ Mantle, is nearly allied to the Burnet; but the flowers are in small corymbs, instead of spikes. The flowers have no petals; but the limb of the calyx is coloured, and divided into eight unequal segments. There are generally four stamens and only one style, though sometimes there are two. The ovary contains one or two carpels, each containing a single seed, and these when ripe are enclosed in a capsule, formed by the tubular part of the calyx becoming hardened. The leaves are lobed, plaited, and serrated at the margin; and those of the Alpine species (A. alpina), which is often found wild on the Scotch mountains, are covered with a beautiful silky substance of the most brilliant whiteness.