In Gaelic the alder is called _fearn_, which appears in a multitude of place-names, such as Balfern, Glenfarne, Farnoch, Fearn, Fernie, and Fernaig. The consonant _f_ being liable in Gaelic to be silenced by aspiration, the descriptive name _amhuinn-fhearn_, alder river, has been worn down into Nairn, and probably some, at least, of the numerous streams called Earn or Erne derive their titles from a similar contraction.
Among the exotic species of alder I only know of one worth attention for ornamental purposes, to wit, the heart-leaved alder (_A. cordata_); which, being found indigenous only in Corsica and Southern Italy, might scarcely be expected to take kindly to our humid climate. It does so, however, growing as vigorously as our native alder, and proving somewhat more decorative. The leaves are of a shining, dark green with lighter undersides, and the cones are at least an inch long, carried erect.
The grey alder (_A. incana_) has nothing to recommend it; except, perhaps, to Norwegian anglers, who know how the fieldfares nest among its thickets in garrulous colonies. It is not easy to understand how the British Isles have missed having this species as a native, for it is very widely distributed over Europe from the shores of the Arctic Ocean on the north to Servia and the Apennines on the south. It is also spread widely over the northern United States and Canada.
[Illustration: TULIP TREE (_Liriodendron tulipifera_)
The tulip tree (_Liriodendron tulipifera_) is descended from an extremely remote ancestry, and remains one of the stateliest denizens of the North American river valleys, ranging from 150 to 190 feet high. The form of its leaves is unique among those of forest trees, being lyrate, ending in two pointed or rounded lobes considerably longer than the midrib. Ruskin declared it to be the only leaf which did not display one form or other of a Gothic arch--round or pointed. These leaves turn a beautiful clear yellow in autumn, and in summer the flowers, in size and shape like those of a tulip, attract numbers of bees. If only they were a little more gaily painted, the tulip tree would be among the showiest of park trees; but the petals are of a dull greenish white, with a splash of orange at the base of the interior of each, where one can't see it--unless one happens to be a bee.