Recognized species are supported by:
Strophostyles helvola (L.) Elliot (legitimate name; but variously called S. helvula)
Strophostyles leiosperma (Torrey & A. Gray) Piper
Strophostyles umbellata (Muhl.
ex Willd.)
Britton

Species identification is still ambiguous due to similar morphological characters and potential interspecific hybridization.
Recognized species are supported by:
Strophostyles helvola (L.) Elliot (legitimate name; but variously called S. helvula)
Strophostyles leiosperma (Torrey & A. Gray) Piper
Strophostyles umbellata (Muhl. ex Willd.) Britton

Species identification is still ambiguous due to similar morphological characters and potential interspecific hybridization.
Strophostyles