DISTRIBUTION. - Represented in both hemispheres from the Arctic zone to the Equator, though rare between the Tropics, and chiefly confined to great elevations. Most numerous in Europe and temperate Asia.-British genera 14, species 45.

Herbs. Leaves opposite. Flowers regular. Stamens definite. Placenta free-central.

Type-Bladder Campion (Silene inflata).

An herbaceous perennial, with ascending stems, opposite entire leaves, definite dichotomous inflorescence, and regular flowers.

OBSERVE the free central placenta, characteristic of the Order. Inside and at the base of the ovary traces of

FIG. 85. Transverse section of an ovary, showing free central
placentation.

arrested dissepiments may be found, indicating that the placenta results from the axile cohesion of the carpels.

Observe, also, the somewhat berried fruit of Cucubalus. A capsule is the characteristic form of fruit in the Order. Several species of the Order are common in gardens, as Clove-pinks, Piccotees, and Carnations, derived from Dianthus Caryophyllus (from the specific name of which species the name of the Natural Order is derived), Sweet William (D. barbatus), Pinks (various species of Dianthus), species of Lychnis, and Soapwort (Saponaria). The last-named and some others of the Family contain a considerable quantity of carbonate of soda or of potash, and may be used in washing linen; hence the name "Soapwort."

Tufts of a Sandwort (Arenaria) are in the Kew Museum, brought from an elevation of 14,000 to 18,000 feet in the Himalaya, by Drs. Hooker and Thomson.

11. Natural Order — Hypericineæ. The St. John'swort Family.

DISTRIBUTION.-Dispersed through tropical and temperate regions of both hemispheres.—One British genus, species II.

Shrubs or herbs. Leaves opposite. Flowers regular. Sepals imbricate. Stamens indefinite, polyadelphous.

FIG. 86.-Vertical section of a flower of Hypericum perfcratum.

Type-Common St. John's-wort (Hypericum perfora

tum).

O. B.

K

A perennial erect herb, with opposite entire glandulardotted leaves, and terminal cymose yellow regular flowers.

:

OBSERVE the immersed glands of the leaves, appearing like translucent dots when held up to the light the dark "glands" on the sepals and petals: the unequalsided petals.

Hypericum is the only British genus with polyadelph

ous stamens.

FIG. 87.-One of the bundles of stamens from the flower of Hypericum.

FIG. 88.-Transverse section of the 3-celled ovary of same, showing axıle placentation.

FIG. 89.-Embryo of same: the short notch separates the cotyledons.

66

A Natural Order (not European) allied to the Hypericums-Ternströmiaceæ-includes the Tea shrub (Thea chinensis), the dried leaves of which we import as Tea" in enormous quantities from China and, of late years, from India. The original culture of tea was confined to China, where it has been in use from remote antiquity; tradition representing it as having been introduced to human notice in fabulous times by a monkey. It is not, however, known in the wild state in China, though it is found native in the jungles of North-Eastern India. From the

cultivated native Indian variety, and from Chinese plants introduced into India, large quantities of Tea are now prepared. The total import of Tea into the United Kingdom in 1877 exceeded 186,000,000 lbs., 151,000,000 lbs. being entered for home use. In the year 1666 Tea was sold in England at 60s. per pound.

Black and green Tea may be prepared from any of the varieties of the Tea plant by peculiar methods of drying; the leaves which are intended for green Tea being dried more rapidly than those destined for black. Inferior kinds of green are artificially coloured. "Brick Tea," used in Central Asia, is made from common kinds and refuse, mixed with bullocks' blood, pressed

and dried in moulds. When used, it is boiled with salt, butter, &c. Brick tea has lately been sold in the London market for re-exportation to Russia.

To the same Natural Order belong also the favourite Camellias of our plant-houses, evergreen shrubs introduced from Japan. The genus Camellia is confined to Eastern and Southern Asia. It is so nearly allied to Thea as scarcely to merit generic separaation. The species are prone to the substitution of petals for stamens in their flowers: hence the Camellia is rarely seen with single flowers.

12. Natural Order-Linaceæ.

The Flax Family.

Slender herbs. Flowers regular. Sepals imbricate.

definite. Placentas axile.

Stamens

DISTRIBUTION.-Scattered through the Tropics, and North temperate zone of both hemispheres.—British genera 2, species 5.

Type-Common Flax (Linum usitatissimum).

An erect tall and slender annual herb, with narrow alternate leaves, and conspicuous blue regular flowers.

OBSERVE an inner whorl of five stamens imperfectly developed, indicated by short filaments without anthers. In some exotic allies the stamens are decandrous from the inner five becoming antheriferous. A cross section of the ovary exhibits, apparently, ten cells. There are really five, each of which becomes more or less "spuriously divided by the infolding of the dorsal suture of each