Williamsonia possessed a sturdy stem and had multiple fern-like leaves.
The plant did not live in groups.
The stamens of Williamsonia curved inward and upward.

Williamsonia produced flowers up to 4 inches (10 cm) in length.
Its stalked seeds would have grown from a central receptacle, and the entire flower of Williamsonia would have been surrounded by protective bracts (which are often the only part of the plant to undergo fossilization).
The cones of Williamsonia were monosporangiate.
They were “cup shaped” and could be up to 15 centimetres (5.9 in) in diameter.
As many as 25-50 ovules could be present in each cone.
The development of the ovules appears to be similar to that of Cycadeoidea.

Early Cretaceous (Berriasian)
Yixian Formation
Huangbangi Valley, Beipiao, Liaoning Province, China
Extremely rare 40mm flower on 102mm slab
Flower, Gymnosperm