staminate, others mixed; ovary in perfect flowers glabrous. Fruit’ with horizontally spreading wings, glabrous or pubescent.
In summer it is distinguishable from all the other small-leaved maples by the leaves being ciliate in margin, with petioles containing milky sap. In winter the corky ridges on older twigs are characteristic; young branchlets are glabrous or pubescent towards the tip, with crescentic three-dotted leaf-scars, which join at their ends around the twigs. Terminal buds sessile, about } inch long, with scales pubescent at the apex and fringed with white cilia. Lateral buds almost appressed to the twigs.
Varieties
Two varieties occur in the wild state both in England and on the Continent ; var. hebecarpum, in which the carpels of the fruit are pubescent, and var. leiocarpum, with glabrous fruit. The leaves show considerable variation in shape and in the amount of pubescence on the lower surface; and six sub-varieties are distinguished by Schneider,’ as follows :—
1, subtrilobum. Leaves three-lobed; fruit pubescent.
2. lobatum. Leaves with five obtuse, toothed lobes; fruit pubescent.
3. acutilobum. Leaves with five acute, almost entire lobes; fruit pubescent.
4. pseudomarsicum. Leaves three-lobed ; fruit glabrous.
5. normale. Leaves with five obtuse, toothed lobes; fruit glabrous. Var. collinum is a form of this, with the leaves glabrous beneath.
6. austriaca. Leaves with five acute, almost entire lobes ; fruit glabrous.
In var. pulverulentum, as cultivated at Kew, the leaves are spotted with white. This appears to be a very slow-growing tree. In var. variegatum the leaves are white in margin.
A hybrid’ between this species and A. monspessulanum has been found wild in Herzegovina, and has been named A. Bornmülleri, Borb. A. neglectum, Lange, described above in the Synopsis, p. 637, is a hybrid between A. campestre and A. pictum, var. colchicum.
Distribution
Acer campestre is spread generally throughout Europe, with the exception of the greater part of Scandinavia, Finland, Northern Russia, and the south of the Iberian Peninsula; and extends into Western Asia, where it is found in the Caucasus and in the province of Astrabad in Persia, where it reaches its most easterly and southernmost point.
In Norway, according to Schübeler, it is not indigenous; but it lives as far north as Trondhjem and grows as tall as 25 feet in the south. Its northern limit as a wild tree, beginning in the province of Scania in South Sweden, crosses into the province of West Prussia in Germany, where it grows at Thorn, and extends through Poland and Central Russia to Vladimir, where it reaches its northernmost
1 A series of abnormal fruits, each with three to eight keys, instead of two, the normal number, is exhibited in the Kew Museum. Cf. Sir W. Thiselton-Dyer in Ann. of Bot. xvi. 556 (1902).
2 Schneider, Laubholzkunde, ii, 230, 231 (1907).
