As in POWO:
http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:799460-1

See also GRIN, which says:

"valid publication verified from original literature
-although the specific epithet is commonly spelled "laevigata", Rafinesque consistently spelled this "levigata" and there is no basis for correcting his spelling"
https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?456532