Page:TheTreesOfGreatBritainAndIreland vol01.djvu/172

144 :::::Scandica. Leaves with 7-9 pairs of nerves, lobes deep, with sharp teeth.
 * Minima. Leaves with 5-7 pairs of nerves, smaller and narrower than in the preceding varieties.
 * Certain forms of Pyrus pinnatifida closely resemble scandica, but the lobing in these will be found always irregular and often very deep.
 * 15. Pyrus lanata, D. Don. Himalayas. Leaves large, broad oblong, woolly underneath, nerves 12-15 pairs, lobes regularly serrate.
 * C. Under surface of the leaves, which are orbicular in outline, snowy-white tomentose.
 * 16. Pyrus Apia, Ehrhart, van flabellifolia. Greece. Leaves with 3-5 pairs of nerves.
 * 17. Pyrus Aria, Ehrhart, var. græca. Greece, Asia Minor. Leaves with 6-10 pairs of nerves.

V. Leaves simple, not lobed, and only occasionally obscurely tabulate.


 * A. Aronia. Leaves finely serrate in margin, with glands on the upper surface of the midrib. This section comprises 2 North American species and a hybrid of garden origin, small shrubs, only referred to here to prevent their being confused with other species of Pyrus.
 * 18. Pyrus arbutifolia, Linnæus fil. North America. Leaves beneath whitish grey tomentose, with about 6 pairs of nerves directed forwards at a very acute angle.
 * 19. Pyrus alpina, Willdenow. A hybrid between Pyrus Aria and the preceding species. Leaves densely grey tomentose beneath, with 9-10 pairs of nerves directed outwards at an angle of 45°.
 * 20. Pyrus nigra, Sargent. North America. Leaves glabrous beneath or very slightly pubescent.


 * B. Leaves without glands on the midrib.
 * (21-22) Leaves glabrous beneath. These 2 species, of which the first is a shrub and the other a small tree, are only referred to here to distinguish them from other species.
 * 21. Pyrus Chamæmespilus, Linnæus. Vosges, Jura, Alps, Pyrenees. Leaves sessile or nearly so, elliptic, with 6-8 pairs of nerves.
 * 22. Pyrus alnifolia, Franchet and Savatier. Japan and China. Leaves stalked, broadly ovate, with 9-12 pairs of nerves.


 * (23-26) Leaves white pubescent beneath.
 * 23. Pyrus Aria, Ehrhart. Europe, Caucasus, Siberia, Central China. Leaves oval or elliptic with very slight lobules or only doubly-toothed, the teeth or lobules diminishing in size from above downwards; nerves 7-12 pairs, very prominent on the lower surface, pubescence snowy white.