Question: how is Hymenocallis and Sinojackia connected?

Context paragraphs:
Hymenocallis: Hymenocallis (US) or (UK) is a genus of American plants in the amaryllis family.

Sinojackia: Sinojackia is a genus of five to eight species of flowering plants in the family Styracaceae, all endemic to China.

Supporting paragraphs: Hymenocallis Sinojackia
Answer: plants