International Aroid Society

KEY TO THE SECTIONS OF SYNGONIUM

Ia. Leaf blades of adult plants simple; leaf blades of juvenile and the pre-adult climbing phases
not markedly different from those of the adult

2a. Leaf blades lacking posterior lobes or the blades merely subcordate ------------------- Section Oblongatum (Species 1-3)

2b. Leaf blades with large, well-developed posterior lobes, the blades ovate, oblong-ovate
or hastate ------Section Cordatum (Species 4-13)

lb. Leaf blades of adult plants markedly divided, trisect, 5-11-palmatisect or incised-lobate;leaf blades of juvenile and pre-adult climbing phases markedly different from those of the adult.

3a. Leaf blades of adult plants incised-lobate (the anterior lobe pinnately lobed); leaf shape of pre-adult climbing phase usually not simple, usually variously lobed but not as deeply lobed as the adult ----- Section Pinnatilobum (Species 14)

3b. Leaf blades of adult plants trisect or 5-1 I-pedatisect; leaf shape of pre-adult climbing phase simple, usually hastate or sagittate -- Section Syngonium (Species 15-33)