Sium rigidius Linnaeus, Species Plantarum 1: 251. 1753.

"Habitat in Virginia." RCN: 2026.

Lectotype (Reveal in Jarvis & al. in Taxon 55: 215. 2006): Clayton 279 (BM-000042233).

Current name: Oxypolis rigidior (L.) Raf. ( Apiaceae).