Noun | 1. | Hippocastanaceae - trees having showy flowers and inedible nutlike seeds in a leathery capsule dicot family, magnoliopsid family - family of flowering plants having two cotyledons (embryonic leaves) in the seed which usually appear at germination order Sapindales, Sapindales - an order of dicotyledonous plants Aesculus, genus Aesculus - deciduous trees or some shrubs of North America; southeastern Europe; eastern Asia |