This widespread eastern taxon of mesic to subxeric woods is largely tetraploid (2n = 56), in contrast to the other segregates of triphyllum (2n = 28). A. triphyllum, like other Araceae, is highly unpalatable due to oxalate crystals, and deer generally avoid it (Frankland & Nelson 2003). However, plants may still suffer from dense deer populations due tto soil compaction and perhaps other damages (Heckel et al. 2010). Forms with purple (typical), striped (forma zebrina) and green (forma viride) spathes are all scattered widely through Ky. Colls. need to be studied more closely to distinguish pusillum; see also notes under other species. A. triphyllum and its close allies (purpurascens, ?striatum, quinatum) differ from pusillum and allies as follows (W, Wyatt et al. 2025): plants with fresh leaves distinctly glaucous or lighter in color on the lower surface (versus similar in color), spathe flange 2-7 mm broad (versus 1-5 mm); spathe apex acuminate to acute (versus acuminate to long-acuminate). These are not reassuring characters!