This plant, the tubers of which for a long time were a luxury obtainable by the rich only, now yields the support of the poor, and furnishes the cheapest food known; the peasantry of Ireland almost subsist upon Potatoes, and the poor of most parts of Europe find it indispensable to their living.
Orders of Monochlamydeæ.
6. Corylaceæ (Castanea vesca) Sweet Chestnut.
(Quercus pedunculata) Oak.
(Corylus avellana) Hazel Nut.
Sweet Chestnut.
This order contains some of our finest trees; the Oak, that prince of trees, is of this order. It attains a great age and size, and there are some celebrated specimens existing which have stood many centuries. Oaks constitute the greater part of the forest trees, both on the Continent and in England; great numbers are cut in France for fire-wood, and in both countries for ship-building. The roof-timbers of our old churches and halls are nearly all oak. The bark of the oak is largely used for tanning leather. About 30,000 tons are imported into this country yearly for this purpose, besides the product of our own trees. The bark of the Cork-oak (Quercus suber) is used for making corks, some 2,000 tons of this are imported annually. Moreover, the Gall-nut used in tanning, and also to make black dye, is the product of an oak. The Chestnut is a fine tree, the nuts of which are commonly eaten by the peasantry of Spain and Italy as food; the tree grows to a great age and to an enormous size.














