Aquifoliaceae

Alternate, often spine-toothed, glossy evergreen leaves on trees and shrubs; tiny, unisexual, four-petalled flowers on separate male and female plants ripen into a bright red berry-like drupe that persists through winter.

Only female plants bear the familiar bright red berries — a male plant nearby is needed for pollination, but it will never itself produce the classic holiday-decoration fruit.

To check whether a plant belongs to Aquifoliaceae, compare the leaf arrangement, leaf type, flower symmetry, fruit type, and one distinctive marker together. A single feature can mislead; the family pattern is the combination.