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This variety occurs in the Caucasus, and is very similar to var. dentzcudata,’ occurring in the same region and in north Persia, which is less pubescent. Var. barbata is in cultivation at Kew.

2. Var. guercifolia, Willdenow, Berlin Baumz. 44 (1796). Oak-leaved alder. Leaves obovate, lobed like the common oak. This variety has been found wild in Sweden.

3. Var. sorbifolia, Dippel, Laubholzkunde, ii. 161 (1892). Service-leaved alder. Leaves oval, lobed like those of Pyrus intermedia. This variety has been found wild in Finland.

4. Var. laciniata, Willdenow, loc. cit. Cut-leaved alder. Leaves (Plate 268, Fig. 7), divided half-way to the midrib into three to six pairs of non-serrated triangular segments ; petiole slender, about an inch long.

The cut-leaved alder, according to Duhamel, occurs wild in the north of France, particularly in Normandy, and in the woods of Montmorency near Paris. Thouin states, according to Loudon, that it was first found by Trochereau de la Berli¢re, and planted by him in his garden near St. Germain, where the stool remained in 1838, from which all the nurseries of Paris were supplied with plants. The largest trees we have seen of this variety are described on p. 942.

5. Var. imperialis, Petzold and Kirchner, Arb. Musc. 599 (1864). Alnus imperialis, Desfossé-Thuillier, Illust. Hort. vi. 97, fig. (1859).

Leaves (Plate 268, Fig. 8) oval, divided more than half-way to the midrib, into six or seven pairs of long narrow lanceolate non-serrated curved segments. This variety, so far as we know, does not attain to as large a size as the ordinary form of the cut-leaved alder. A specimen at Ponfield, Hertford, is 25 feet high by 1 foot 8 inches in girth.

6. Var. incisa, Willdenow, Sp. Pl. iv. 335 (1805) (var. oxyacanthæfolia, Loddiges, Catalogue, 1836). Thorn-leaved alder. Leaves (Plate 268, Fig. 10) small, deeply incised, resembling those of the common hawthorn. A fine specimen, 44 feet high by 2 feet 8 inches in girth, is growing in the arboretum at Barton, near Bury St. Edmunds.

7, Var. rubrinervia, Dippel, loc. cit. A tree, pyramidal in habit, with large and shining leaves, furnished with red petioles and nerves, vigorous in growth and handsome in appearance. In cultivation at Aldenham.

8. Var. pyramidalis, Dippel, loc. cit. Branches erect, leaves as in the type.

9. Var. aurea, Verschaffelt, ex Dippel, loc. cit. Lemaire, Illust. Hortic. 1866, t. 490. Leaves yellow. Found as a seedling in Vervaene’s nursery at Ledeberg-les-Gand. In cultivation at Aldenham.

10. Var. maculata, Winkler, loc. cit. Leaves variegated with yellow. There is a small specimen at Aldenham, which is slow in growth.

Hybrids? between Alnus glutinosa and Alnus incana are common in the wild state, where the two species are growing together, and have been observed in

1 Ledebour, loc. cit. Alnus denticulata, C.A. Meyer, loc. cit.

2 A. glutinosa × incana; A. spuria, Callier. Schneider, Laubholzkunde, 130 (1904), distinguishes three forms of this hybrid.