There have been several reports under this name (Short & Peter 1835; and citations of M), but colls. need location and verification. H. marianum is poorly understood but widely reported in southeastern states, apparently derived from hybrids of venosum and gronovii (W). An allied taxon, H. traillii Greene, was also mapped in Ky. by FNA 19, but most potential records (M) are from colls. of B (US) that were initially named under the synonym, H. greenii Port. & Brit. (not to be confused with the true H. greenei Gray of western states). H. traillii probably has hybrid origin similar to marianum but is endemic to the shale-barren region of Pa., W.Va. and Va. (FNA 19). B's colls. of "greenii" may be referable to marianum, but initial examination suggests that they could just be interpreted as depauperate gronovii. They are from BATH, BOON, LAUR, LETC, MCRE, MENI and WOLF.