144 ^^^ Trees of Great Britain and Ireland 



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. Pypus 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. gfrseca. 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. Pypus arbutifolia, Linnaeus fil. North America. Leaves beneath 



whitish grey tomentose, with about 6 pairs of nerves directed forwards 

 at a very acute angle. 



19. Pypus 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. Pypus 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 Charasemespilus, Linnaeus. Vosges, Jura, Alps, Pyrenees. 



Leaves sessile or nearly so, elliptic, with 6-8 pairs of nerves. 



22. Pypus alnifolia, Franchet and Savatier. Japan and China. Leaves 



stalked, broadly ovate, with 9-12 pairs of nerves. 



(23-26) Leaves white pubescent beneath. 



23. Pypus Apia, 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 down- 

 . wards ; nerves 7-12 pairs, very prominent on the lower surface, 

 pubescence snowy white. 



