Stephania auriformis was an early Eocene member of the moonseed family, known from the hard inner stone of its fruit. Menispermaceae today are dominated by climbing plants, and placement in the living genus Stephania makes a climbing habit plausible, although the London Clay fossil itself preserves the fruit rather than attached stems or leaves.

The endocarp formed a tough protective case around the seed. Its horseshoe-shaped seed cavity, central opening and ribbed dorsal crest are characteristic of Stephania-type fruits. The species also occurs outside Britain, showing that this fruit form had a wide Palaeogene distribution.