As Alders in the spring, their boles extend,
And heave so fiercely that the bark they rend.
Virgil, ecl. x.
Vitruvius informs us, that the morasses about Ravenna were piled with this timber to build upon; and Evelyn says that it was used in the foundations of Ponte Rialto, over the Grand Canal at Venice. The wood is also valuable for various domestic purposes.
Besides the common Alder there are introduced at least six other species:—
1. A. Glutinosa, already described.
2. Emarginata, leaves nearly round, wedge-shaped, and edged with green.
3. Laciniata, leaves oblong and pinnatifid, with the lobes acute.
4. Quercifolia, leaves sinuated, with the lobes obtuse.
5. Oxyacanthœfolia, leaves sinuated and lobed; smaller than those of the preceding variety, and somewhat resembling the common hawthorn.
6. Macrocarpa, leaves and fruit larger than those of the species.