This northeastern taxon of wet peaty woods and thickets (F, W) has been reported from BELL or KNOX by Treiber (1980), perhaps based on a coll. at GH. K (in previous editions) has mapped other records from e. Ky. However, no clearly verified colls. have been located. In Tenn., the only verified records may be from higher elevation at the northeast corner of that state (Carter & Johnson Cos.), based on SERNEC (2024). In the keys of W and Wyatt et al. (2025), stewardsonii differs from pusilllum as follows: spathe tube strongly fluted (versus not so or rarely weakly fluted); spathe hood interior green or purple with conspicuous white stripes (versus green or purple usually without well-defined white stripes); spadix 4-6 mm in diameter (versus 2-3 mm); spathe apex long-acuminate (versus acuminate).