CHAPTER VIII.
THE ORDER OLEACEÆ, OR JASMINEÆ: ILLUSTRATED BY THE COMMON WHITE JASMINE; THE YELLOW JASMINE; THE PRIVET; THE PHILLYREA; THE OLIVE; THE FRINGE-TREE (_Chionanthus Virginica_); THE LILAC; THE COMMON ASH; AND THE MANNA OR FLOWERING ASH.
This order was established by Jussieu, who divided it into two tribes—Jasmineæ and Oleineæ, which are now very generally considered as distinct orders. I have, however, thought it best to keep them together, as I wish to make as few divisions as possible, to avoid burthening the memory of my readers. All the genera in both tribes agree in their flowers having only two stamens, an ovary with two cells, and two seeds in each cell; and anthers with two cells, which open with a long slit lengthways.
The species of the Ash have no corolla; but in all the genera where there is one, the filaments of the stamens, which are very short, are inserted in it; and it is generally funnel-shaped—as, for example, the corolla of the Jasmine. Though the ovary is two-celled, and the cells two-seeded, each flower very often only produces one perfect seed. The leaves are generally pinnate.
TRIBE I.—JASMINEÆ.
The genus Jasminum is the only one in this tribe which contains plants common in British gardens; and of all the species contained in it, the common white Jasmine (_J. officinale_) is perhaps the best known. The flowers are produced in terminal clusters of four or six. The calyx is tubular, with the limb cut into numerous narrow segments; (see _a_ in _fig._ 64;) and the corolla is funnel-shaped, with a spreading limb (_b_) divided into four or five pointed segments, which are folded over each other, and somewhat twisted in the bud. The two stamens and the style and stigma are enclosed in the corolla; and the fruit is a berry divided into two cells, with one seed in each. There is no albumen in the seeds. The leaves (_c_) are impari-pinnate, with the single terminating leaflet larger than the others; and the petioles are articulated. The common yellow Jasmine (_J. fruticans_) has flowers in terminal clusters of three each, and its leaves are either ternate, that is, with three leaflets, or simple. The branches are angular, and the leaves quite smooth. The Nepaul yellow Jasmine, (_J. revolutum_) has pinnate leaves of five or seven leaflets, which are smooth and shining. The flowers are large and produced in compound corymbs. They are a bright yellow, and very fragrant. The segments of the corolla are obtuse, and the stigma club-shaped. There are above seventy species of Jasmine, more than twenty of which have been introduced into Britain; but they may be all easily recognised by their flowers, which bear a strong family likeness to each other, and by the petioles of their leaves, which are always articulated or jointed, that is, they will break off the stem without tearing the bark. In other respects the leaves vary exceedingly in this genus, some being simple and others compound; and some being opposite, as in the common Jasmine, and others alternate, as in _J. revolutum_.
TRIBE II.—OLEINEÆ.
This tribe contains numerous genera, among which the most common are the Privet (_Ligustrum_), Phillyrea, the Olive (_Olea_), the Fringe-tree (_Chionanthus_), the Lilac (_Syringa_), the Ash (_Fraxinus_), and the Flowering or Manna Ash (_Ornus_). All these genera agree in their general character with Jasminum, except as regards their seeds, which abound in albumen.
In the common Privet (_Ligustrum vulgare_), the flowers, which are produced in terminal compound racemes, have a very short calyx (see _a_ in _fig._ 65), with a funnel-shaped corolla, having a wide tube in proportion to the limb (_b_), which is very short and divided into four segments. The anthers of the stamens and the stigma are seen in the throat of the corolla. The berry is drupe-like, and generally contains two one-seeded nuts. The leaves are simple and opposite. There are many species of Privet, but the handsomest is _L. lucidum_, the leaves of which are broad and shining, and the panicles of flowers spreading. This tree yields a kind of waxy matter from its leaves and branches when boiled, which is said to be used by the Chinese for candles.
The Phillyrea is a handsome evergreen shrub, very useful in shrubberies, from its forming a close compact bush of a deep green, which makes a good background to Tree Roses, Almond-trees, _Magnolia conspicua_, or any other flowering plant that would appear naked if its flowers were not relieved by a background of green. The flowers of the Phillyrea are small and of a greenish white. The fruit is a drupe, containing a two-celled stone or nut, but with seldom more than one perfect seed.
The Olive (_Olea sativa_) has small white flowers, resembling those of the Privet, and a fleshy drupe like a Sloe, with a one or two celled stone or nut. The oil is contained in the fleshy part of the fruit, and the best oil is that which is obtained by crushing the pulp of the fruit without breaking the stone or nut.
The Fringe-tree (_Chionanthus virginica_) differs from the preceding genera in the length of the segments of the limb of its corolla, which is cut into long slender shreds like fringe. In all other respects except that the pulp of the fruit does not contain oil, this genus is closely allied to the Olive.
The common Lilac (_Syringa vulgaris_) has its flowers disposed in a kind of panicled raceme called a thyrsus. The calyx is very small, and obscurely four-toothed (see _a_ in _fig._ 66), and the corolla (_b_) is funnel-shaped, with a four-parted limb; the stigma is two-cleft, and both the style and stamens are enclosed in the tube of the corolla. The fruit is a dry two-celled and two-seeded capsule, which opens with two valves, as shown at _c_, each valve having a narrow dissepiment down the middle: the shape of the seed is shown at _d_. The leaves are simple, opposite, and entire; and the branches are filled with pith, which may easily be taken out and the branch left hollow like a pipe; and hence the generic name of Syringa, from _Syrinx_ a pipe.
The Ash (_Fraxinus excelsior_) differs so much from the other genera as to seem scarcely to belong to the same order. The flowers are without any petals, and frequently without any calyx; and some of them, which are called the female flowers, have no stamens, while others, which are called the males, have no pistil. Some of them, however, have both stamens and pistil. The fruit is what is called a samara or key; that is, it is furnished with a membrane-like wing so as to resemble a dry leaf. It is two-celled, but very frequently only one-seeded. The shape of the keys, and the manner in which they grow, is shown at _a_ in _fig._ 67; and the leaves, at _b_. The leaves are opposite and generally pinnate, with five or six pairs of leaflets; but there is one species with simple leaves (_Fr. simplicifolia_). The Weeping Ash is only an accidental variety of the common kind. The leaves of the Ash come out late and fall early; but the tree may easily be recognised when quite bare by the greyness of its bark and its black buds. It will grow in any soil; but it is injurious to arable land, from its roots spreading widely near the surface.
The Manna, or flowering Ash, (_Ornus europæus_), differs widely from the common Ash in its flowers, which are white, with a corolla divided into four long narrow segments. The two stamens have long filaments, with a small pistil (_c_), the stigma of which is notched. The flowers are produced in great profusion in loose panicles, and they are very ornamental, the samaras and leaves closely resembling those of the common ash. There are several species of this genus, which were all formerly included in the genus Fraxinus. The Manna is the sap of the tree, and it is procured by wounding the bark.