Taxonomy ed. 3, 253 (1897), vide Merrill in Castanea, 13: 67 (1948)
Taxonomy ed. 3, 253 (1897), vide Merrill in Castanea, 13: 67 (1948) [details]
Compositae Working Group (CWG) (2025). Global Compositae Database. Helianthus undulatus Chapm.. Accessed at: https://www.compositae.org/gcd/aphia.php?p=taxdetails&id=1140392 on 2025-09-12