ORDER XXXI.--TILIACEÆ.--THE LINDEN TRIBE.
FIG. 120.--THE FLOWERS AND SEED-VESSEL OF THE COMMON LIME TREE.
The only genus belonging to the natural order Tiliaceæ which is easily to be procured in Britain is that of Tilia, the Lime trees. The common Lime (_Tilia europæa_) is generally a tall, well-formed tree, with rather broad leaves, which are heart-shaped at the base, tapering at the point, and serrated at the margin: they are also smooth on the outer surface, thin, and of a light and delicate texture; below there is a little tuft of hair at the angle of the veins. The flowers are produced in cymes or compound umbels (see _fig._ 120); and their main pedicel appears to spring from one long entire bract (_a_). The calyx is in five sepals, and it falls off before the corolla, which is composed of five pale yellow petals, which are very sweet-scented.
The stamens are numerous, and the filaments separate, bearing two-celled anthers, which burst by long slits. The ovary has only one style, the tip of which is cleft into five small stigmas; and it is divided into five cells, each containing one or two ovules. The fruit or capsule (_b_) is round, and has a leathery skin, covered with a soft down; and when ripe, the cells often become united so as to form one, with only one or two perfect seeds in the whole capsule, the other ovules proving abortive. The whole plant abounds in mucilage, and the sap when boiled affords sugar. The inner bark is so tough and fibrous, that it is used for making what are called bast mats: it being first rendered flexible by steeping it for a long time in water. The wood is of very fine texture, but soft and white, and it is thus admirably adapted for carving. The American Limes have a small scale at the base of each petal of the flower; but the other differences between the species are very slight.
ORDER XXXII.--ELÆOCARPÆ.--THE ELÆOCARPUS TRIBE.
East India shrubs and trees, little known in Britain. "The hard and wrinkled seeds of Elæocarpus are made into necklaces in the East Indies, and, set in gold, are sold in our shops."--(_Hook._)
ORDER XXXII*.--DIPTEROCARPÆ.--THE CAMPHOR TREE TRIBE.
There are two kinds of Camphor, one produced by boiling the branches of a kind of laurel, and the other (the Camphor of Sumatra) is found in large pieces in the hollow parts of the branches of _Dryobalanops Camphora_, one of the species included in this order. None of these trees have been introduced into Britain.