Desmodium glabellum is a
species of
flowering plant in the
legumefamilyFabaceae. It is native to the eastern and central United States. It is commonly called Dillenius' tick-trefoil in honor of
Johann Dillenius, a British botanist of German birth. It is also known as the tall tick-trefoil.
Description
Desmodium glabellum is a
herbaceousperennial plant. It grows to 5 feet tall with alternate palmately trifoliate leaves. Light pink to purplish flowers appear June through September. Seeds in sticky pods arranged in a row of 2-5 segments appear August–October. This species is very similar to Desmodium perplexum from which it was recently split.[4]
Taxonomy
Desmodium glabellum was first described as Hedysarum glabellum by the French botanist
André Michaux in 1803.[5] The
type specimen was collected in a grassland in "Lower Carolina".[6] Michaux described the stem of the species as nearly
glabrous,[7] hence the specific name glabellum and the corresponding common name smooth tick-trefoil (not to be confused with Desmodium laevigatum, which also goes by that common name). In 1825, the Swiss botanist
Augustin de Candolle placed Hedysarum glabellumMichx. in genus Desmodium,[2] and so Hedysarum glabellum is a
basionym for Desmodium glabellum(Michx.) DC.[3]
The American physician, botanist, and politician
William Darlington described Desmodium dillenii in 1837.[8][9] Darlington's description was based upon an illustration of Hedysarum trifoliatum published by the German-born British botanist
Johann Jacob Dillenius in 1732.[10][11] Recognizing Dillenius' contribution, Darlington referred to Desmodium dillenii as Dillenius's Desmodium. In 1950, the American botanist
Bernice Schubert rejected Desmodium dilleniiDarl. as a nomen confusum (a term having no standing in the
International Code of Nomenclature of 2018),[12] which means "confusing name". In an attempt to resolve the confusion, Schubert split the
taxon into two distinct taxa, a newly described Desmodium perplexum,[13] and the previously described Desmodium glabellum. However, Schubert did not identify the plant in Dillenius' illustration. The matter remained unresolved until 2020 when the
morphologies of the taxa in question were sufficiently clarified.[14] Subsequently the plant in Dillenius' illustration was identified as Desmodium glabellum,[15] and hence the name Desmodium dilleniiDarl. is a
synonym for Desmodium glabellum(Michx.) DC.[16] The common name Dillenius' tick-trefoil is often used to refer to Desmodium glabellum.[1][17][18][19]
Desmodium glabellum is a member of the Desmodium paniculatum complex, a group of closely related taxa that also includes Desmodium paniculatumsensu stricto, Desmodium perplexum, Desmodium fernaldii, and the synonym Desmodium dillenii.[20] Alternatively, some botanists lump these taxa into a single
polymorphic species, Desmodium paniculatumsensu lato,[21][22] in which case Desmodium glabellum becomes a synonym of Desmodium paniculatum.
Distribution and habitat
Desmodium glabellum is native to the eastern and central United States.[23] It grows in fields, woodland borders, and disturbed areas.[24]
^USDA, NRCS (n.d.).
"Desmodium glabellum". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 31 January 2024.
^"Desmodium glabellum". State-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 2 February 2024.
^Weakley, Alan S.; Southeastern Flora Team (2024).
"Desmodium glabellum". Flora of the southeastern United States. University of North Carolina Herbarium, North Carolina Botanical Garden. Retrieved 31 January 2024.