genera, Hook.

Turner, Ian M. & Utteridge, Timothy M. A., 2016, Whither Polyalthia (Annonaceae) in Peninsular Malaysia? Synopses of Huberantha, Maasia, Monoon and Polyalthia s. s., European Journal of Taxonomy 183, pp. 1-26 : 2

Key to genera

1. Lower surface of leaves densely covered with minute papillae giving a white or glaucous appearance .............................................................................................................................................. Maasia

– Leaves not white or glaucous below .................................................................................................. 2

2. Leaf venation herringbone (eucamptodromous) with insertion of lateral veins to the midrib decurrent; intercostal venation scalariform to subscalariform ............................................................. Monoon

– Leaf venation looping (brochidodromous) with insertion of the lateral veins to the midrib not decurrent; intercostal venation reticulate ........................................................................................... 3

3. Leaf base generally more or less symmetrical, not (sub)cordate. Ovules 1 per carpel. Seeds 1 per monocarp ...................................................................................................................... Huberantha

– Leaf base generally more or less asymmetrical, often (sub)cordate. Ovules usually 2–6 per carpel. Seeds usually 2 or more per monocarp ............................................................................ Polyalthia