Acer L.
Genus composed of about 153 species of trees and shrubs, distributed through temperate regions of the northern hemisphere to the temperate mountains of Java and Malaysia, with a diversification centre in China. In North Africa it is represented at least by 4 taxa included in 3 species, all distributed through the more humid environments of the Mediterranean area.
Mediouni, K. & Azira, F. 1992. Contribution à l’étude de la dynamique des formations à Erables (Acer) d’Aït Ouabane (Djurdjura). Foret Médit., t XIII 2: 109-114.
Pignatti, S. 1982. Flora d’Italia. Volume II. Edagricole, Bologna.
Van Gelderen D.M. et al. 1994. Maples of the world. Timber Press Inc. Hong Kong.
Key to species
1 Plants with latex, noticeable in petiole of freshly cut leaf. Fruit with wings slightly tapered at the base, forming an angle greater than 160º Acer campestre
1 Plants without latex. Fruit with wings tapered at the base generally forming an acute angle, sometimes slightly obtuse, up to 110°(120°) 2
2 Leaves with 3 subequal lobes, rarely with 2 small basal lobes, with entire margin or with very small and few teeth Acer monspessulanum
2 Leaves with 5 unequal lobes; basal lobes smaller, rarely absent; with irregularly dentate or serrated margin 3
3 Leaves up to 8(10) cm, with the upper lobes of parallel sides, rarely converging toward the apex, rather deep (at least up to halfway). Undersides ± densely hairy, at least along main veins Fruits with wings that form an angle up to 70 ° Acer opalus subsp. granatense
3 Leaves larger, up to 18(20) cm, with upper lobes with converging sides, shallow (less than a third of the leaf). Undersides densely tomentose. Fruits with wings that form a generally larger obtuse angle Acer opalus subsp. neapolitanum
Updated by: P. Sánchez Gómez & J.F. Jiménez Martínez.