According to Cássio van den Berg, who studied their phylogeny, Loefgrenianthus is closely related to Leptotes and both form a sister clade to another small clade that includes Pseudolaelia, Constantia and Isabellia.
Larval host: Florida fishpoison tree is a larval host plant for several butterfly species including: the native cassius blue butterfly (Leptotes cassius) and hammock skipper (Polygonus leo) and the introduced fulvous hairstreak (Electrostrymon angelia).