A woody climber, with opposite entire leaves, and terminal heads of fragrant irregular flowers.

OBSERVE the thick cellular pith of Elder (Sambucus nigra), useful for pith-balls for electrical experiments, and the cylinder of wood, after the pith is removed, for popguns. Observe, also, the enlarged lobes of the corolla in cultivated varieties of Guelder Rose (Viburnum Opulus). In the wild form, the outer flowers only of the cymes are enlarged in this way, at the expense of the essential organs: they are barren or neuter, in consequence.

Observe, also, Tuberous Moscatel (Adoxa moschatellina), a low, tender herb, with small capitate flowers, of which the upper one of each head has 4, and the four lateral flowers each 5, stamens. The stamens are branched, and each branch bears one lobe of the anther, so that the flowers appear to be octandrous or decandrous. Compare the neuter flowers of Guelder Rose and Hydrangea in the former the lobes of the corolla, in the latter the lobes of the calyx, are enlarged.

Linnæa borealis, a small creeping wiry evergreen, with pretty pendulous flowers, native of Scotland, and common in the North of Europe, is named after Linnæus, who is represented in his portraits with a sprig of this plant in his button-hole.

34. Natural Order-Rubiaceæ. Tribe Stellatæ. The Stellate Tribe of the Madder Family.

DISTRIBUTION.-Dispersed through temperate regions of both hemispheres ; less numerous between the tropics, where, however, typical Rubiaceæ abound. - British genera 4, species 14.

Herbs. Leaves verticillate.

Corolla epigynous. Stamens

epipetalous. Ovary 2-celled.

Type-Sweet Woodruff (Asperula odorata).

A perennial herb, with slender creeping rhizome, erect stem with verticillate leaves, and a terminal cyme of small white flowers.

All British Rubiaceæ belong to the Tribe Stellatæ, characterised by the leaves in whorls. The more typical members of the Order abound in tropical countries, where many species are amongst the commonest weeds. Others, however, are highly ornamental, and are cultivated in our plant-houses. A few species are of great economic importance, especially the Coffee shrub (Coffea arabica) a native of Eastern Tropical Africa, but cultivated very extensively in Ceylon, the East and West Indian Islands, and Brazil. The seeds are contained, two together, in a fruit of about the size and colour of a Cherry. The pulp of the pericarp is removed by washing and mechanical contrivance, leaving the parchment

like endocarp immediately enclosing the seeds to be separated in a rolling-mill.

In 1890 upwards of eight hundred and sixty-four thousand cwts. of Coffee were imported. More than two hundred and fifty-six thousand cwts. were entered for home consumption.

Other important exotic species are the Quinine-producing Cinchonas or Peruvian barks, natives of the Andes of Peru, and now introduced into British India and Java Ipecacuanha, the emetic root of Cephaëlis Ipecacuanha: and Rubia tinctorum, a plant of the Levant and Southern Europe, cultivated in France for the sake of its rhizome, which affords the valuable dye, Madder. Upwards of 283,000 cwts. of Madder and Garancine (the latter prepared from Madder by the action of sul

phuric acid) were imported in 1872. Indian Madder is the produce of an allied species, R. cordifolia.

The seeds of Cleavers, or Goose-grass (Galium Aparine), are said to have the flavour of Coffee when roasted.

35. Natural Order-Valerianeæ. The Valerian Family. DISTRIBUTION.-Principally confined to the north temperate zone and South American Andes.-British genera 2, species 6.

Herbs. Corolla epigynous.

Stamens epipetalous, fewer than

corolla-lobes. Fruit I-celled.

Type-Common Valerian (Valeriana officinalis). An erect perennial herb, with opposite pinnatifid leaves, and terminal many-flowered cymes of small pale lilac or white flowers.

OBSERVE the dioecious flowers of Marsh Valerian (Valeriana dioica): the calyx of the ripe fruit of Common Valerian; at the time of flowering, the limb of the calyx is represented by a thickened rim, but as the fruit ripens the limb expands in the form of a crown of feathered hairs (pappus): the gibbous one-sided dilatation of the base of the corolla-tube in the same species; in Centranth (Centranthus) it is lengthened down into a spur: a transverse section of the ovary exhibits but a

single cell containing one ovule, the other two cells being aborted.

Spikenard is the root of Nardostachys jatamansi, a North Indian plant. It has been highly valued as a perfume from early antiquity. The root of Common Valerian possesses a strong and peculiar odour, which acts powerfully on the nervous system of cats.

Corn-salad, or Lamb's-lettuce (Fedia olitoria), is eaten as a salad.

36. Natural Order-Dipsacea. The Teasel Family.

DISTRIBUTION. -Temperate regions of the Old World, especially around the Mediterranean; also at the Cape of Good Hope.-British genera 2, species 5.

Herbs. Stamens epipetalous, same number as corolla-lobes. Ovary I-celled, inferior. Ovule pendulous.

Type-Blue Scabious (Scabiosa succisa.)

Herb with a præmorse (truncate) rootstock, opposite entire leaves, and terminal involucrate flower-heads.

OBSERVE the small involucel enclosing each individual flower, very easily mistaken for a calyx: the rigid pointed bracts of the flowers of Fuller's Teasel (D. fullonum). The heads are fixed into frames, and used to give a