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142, The Trees of Great Britain and Ireland
5. Sorbus. Ovary with 3 or 5 cells, styles free. Fruit crowned by the calyx,
endocarp membranous or coriaceous. Leaves pinnate. Includes two sub
sections :
Aucuparia, with 3-celled ovary and small globular fruit, and
Cormus, with 5-celled ovary and large pear- or apple-shaped fruit.
6. Aria. Ovary with 2 to 5 cells, styles free. Fruit crowned by the calyx, endo
carp membranous, flesh granular. Leaves simple. Includes the whitebeam
and its allies.
7. Micromeles. Ovary with 2 to 3 cells. Fruit small, globose, umbilicate, endo
carp membranous or coriaceous, calyx-lobes deciduous. Leaves simple.
Includes several Asiatic species.
SYNOPSIS OF THE PRINCIPAL SPECIES IN CULTIVATION EXCLUSIVE OF
PEARS AND APPLES.
(Cf. Plates 43-45 where leaves of most of the species are shown.)
I. Leaves regularly pinnate, the leaflets being separate and never decurrent by their
bases on the rhachis.
A. Aucuparia. Mountain ashes. Leaflets unequal-sided at the base. Fruit small,
not exceeding \ inch.
(1-3) Winter buds •white-tomentose.
1. Pyrus Aucuparia, Gaertner. Europe, Northern Asia, Japan. Young
branchlets and leaves pubescent, adult leaves glabrous or only slightly
pubescent beneath. The common mountain ash.
2. Pyrus lanug-inosa, DC. South-eastern Europe. Only differs from the
preceding in the adult leaves being densely woolly beneath.
3. Pyrus thianschanica, Regel. Chinese Turkestan. Young branchlets
and leaves glabrous ; adult leaves quite glabrous beneath and con
spicuously veined on the upper surface.
(4-5) Winter buds shining, glutinous, glabrous or sparingly pubescent, the
pubescence appressed and of a rusty colour.
4. Pyrus americana, Torrey and Gray. North America. Leaflets long,
narrow, acuminate, glabrous beneath.
5. Pyrus sambucifolia, Chamisso and Schlechtendal. Manchuria, North-
East Asia, Japan, North America. Leaflets broader than in No. 4,
obtuse or acute (not acuminate), more or less pubescent beneath.
B. Cormus. True Service. Leaflets nearly equal sided at the base. Fruit large,
inch diameter or more.
Pyrus
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^
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 shaped
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 tmnentose.
12. Pyrus cratsegifolia, 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.