References

For Forsythia

Green. 2004. In Kadereit, J.W. 2004. The families and genera of vascular plants. VII. Flowering plants – Dicotyledons – Lamiales (except Acanthaceae including Avicenniaceae). Springer, Berlin. 478 pp.

Hardin, J.W. 1974. Studies of the southeastern United States flora. IV. Oleaceae. Sida 5: 274-285.