Acer oblongum is andromonoecious and exhibits cryptic monoecy.
It possesses three types of floral morph: Staminate type I, Hermaphrodite type and Staminate type II flowers on same individuals.
Early blooming Staminate type I flowers may serve to attract and sustain bees.
Hermaphrodite flowers do not possess male function because the anthers are indehiscent.
Staminate type II flowers are involved in pollination and fertilization events.