Stenanthium is a small North American genus of flowering plants in the family Melanthiaceae, order Liliales, placed within the tribe Melanthieae. Plants in the genus are commonly known as featherbells. Members are herbaceous perennials that grow from a slender, cylindrical bulb — a trait that distinguishes them from closely related genera such as the deathcamases — and produce brown seeds that lack a fleshy outer seed coat (sarcotesta).
The genus has been significantly reshaped by 21st-century molecular phylogenetic research. Several species formerly placed in Stenanthium were transferred to the genus Anticlea, while two or three species previously assigned to Zigadenus (the deathcamases, sensu lato) were brought into Stenanthium. The exact number of accepted species remains a matter of taxonomic opinion: the Flora of North America and the USDA recognize two species (Stenanthium gramineum and Stenanthium occidentale), while other authorities recognize additional segregate species including S. leimanthoides, S. densum, S. macrum, and S. tennesseense. Plants of the World Online treats S. occidentale as belonging to Anticlea rather than Stenanthium. The species recognized in the genus occur in the eastern and south-central United States.
Distribution
Stenanthium species occur in the eastern and south-central United States. The genus is restricted to North America.
Taxonomy Notes
Molecular phylogenetic studies in the early 21st century substantially revised the circumscription of Stenanthium. Three former members were transferred to Anticlea, and two to three species from Zigadenus sensu lato were incorporated. The number of accepted species remains unsettled: Flora of North America recognizes two, while additional taxa such as S. leimanthoides, S. macrum, and S. tennesseense are accepted by some authorities.
