Stillingia is a genus of flowering plants in the family Euphorbiaceae, order Malpighiales, comprising shrubs and subshrubs commonly known as toothleaf. The genus was first described for science in 1767, published in Mantissa Plantarum by Linnaeus. Members of the genus are distributed across Latin America, the southern United States, and various islands in the Pacific and Indian Oceans, typically growing in open, sandy habitats such as sandhills and pine flatwoods.
Plants in the genus are herbs or subshrubs, often with alternate, ovate leaves bearing serrulate or crenulate margins — a character that gives rise to the common name "toothleaf." Stillingia is known to contain diterpene esters, a chemical class of biological interest. The most widely known species, Stillingia sylvatica (queen's-delight), is an herb or subshrub of the south-central and southeastern United States averaging 25–70 cm in height, flowering from March to June.
The genus was considerably larger historically, but many former members have since been transferred to related genera, including Actinostemon, Excoecaria, Gymnanthes, Maprounea, Sapium, Sebastiania, and Triadica, among others, as molecular and morphological study has refined the circumscription of Euphorbiaceae tribes.
Etymology
The genus name Stillingia honors Benjamin Stillingfleet (1702–1771), a British botanist and naturalist. The genus was established in 1767.
Distribution
Stillingia is native to Latin America, the southern United States, and various islands in the Pacific and Indian Oceans. In the United States, species such as S. sylvatica and S. texana are found in sandy, open habitats including sandhills and pine flatwoods of the south-central and southeastern states.
Ecology
Species of Stillingia characteristically grow in sandy, well-drained soils in open habitats such as sandhills and pine flatwoods. Stillingia sylvatica (queen's-delight) is associated with the sandy soils of the southeastern United States coastal plain, where it flowers between March and June.
Taxonomy Notes
The genus was first described in 1767 and published in Mantissa Plantarum. Its circumscription has changed substantially: many species formerly placed in Stillingia have been transferred to related genera including Actinostemon, Adenopeltis, Anomostachys, Balakata, Bonania, Ditrysinia, Excoecaria, Grimmeodendron, Gymnanthes, Homalanthus, Maprounea, Microstachys, Neoshirakia, Sapium, Sclerocroton, Sebastiania, Shirakiopsis, Spegazziniophytum, Spirostachys, and Triadica.
