Page:TheTreesOfGreatBritainAndIreland vol01.djvu/171

6. Pyrus Sorbus, Gaertner. Central and Southern Europe. Winter buds greenish, viscid, pubescent only at the tip; under surface of the leaves slightly pubescent in spring, soon becoming glabrous.

 

II. Leaves pinnate, but upper 3 or 5 leaflets coalesced or decurrent by their bases on the rhachis.^[1]

7. Pyrus Aucuparia, Gaertner, var, satureifolia, Koch. A hybrid. Differs from the common form in the coalescence into one large segment of the 3 upper leaflets; leaflets glabrous beneath.

8. Pyrus Aucuparia, Gaertner, var. decurrens, Koehne (Pyrus lanuginosa, Hort. non DC.) A hybrid. Upper leaflets decurrent on the rhachis by broad bases, often the upper 3 or 5 coalescing into one segment; leaflets tomentose beneath.

 

III. Leaflets pinnate or deeply cut at the base, with 1-4 pairs of segments, the upper part of the leaf lobed or serrate; leaves very variable in shape.^[1]

9. Pyrus hybrida, Moench. A shrub of hybrid origin. Main axis of the leaf glandular above, under surface of the leaf sparingly pubescent, the parents being Pyrus aucuparia and Pyrus arbutifolia.

10. Pyrus pinnatifida, Ehrhart. A hybrid. Axis of the leaf without glands, under surface densely grey tomentose.

 

IV. Leaves simple, lobed.

A. Under surface of the leaf glabrous, or nearly so, light green in colour.

11. Pyrus torminalis, Ehrhart. Europe, Algeria, Asia Minor, and the Caucasus.

B. Under surface of the leaf grey tomentose.

12. Pyrus cratægifolia, Savi. Italy. Leaves small, resembling those of a hawthorn, on each side 4-6 triangular-ovate toothed lobes.

13. Pyrus latifolia, Boswell Syme. Britain, France, Spain, Central Europe. Leaves broad-oval with a wide base; lobes decreasing from below upwards, small triangular, separated by sinuses, which form a right angle and are not narrowed. In some forms the lobes are mucronate, in others cuspidate; and, in var. decipiens, the outline of the leaf is like intermedia, but the lobing is different.

14. Pyrus intermedia, Ehrhart. Europe. Leaves elliptic, with a usually narrow base, lobes decreasing from below upwards, rounded, mucronate, separated by narrow sinuses, which are very acute or almost closed at their bases. This includes several forms:—

Mougeoti. Leaves with 9-12 pairs of nerves, lobes shallow.

1. These two sections comprise hybrids, the leaves of which vary in shape, not only on different individual trees, but often also on a branch. Hybrid origin may always be suspected when such variation is observed, or when the lobing or cutting is irregular and not symmetrical.