Much new information about the vascular plants of Iowa has resulted from three years of botanical exploration in various parts of the state since the first Notes were presented in 1953. Some of the more interesting results of the author\u27s botanical gleanings in the period 1953-1955 have been published (Aikman and Thome 1956, Beal and Monson 1954, Cooperrider 1955a and 1955b, Grant and Thorne 1955, and Thome 1955.) Much more data, however, about species not previously reported from Iowa or rarely collected in the state should be placed on record for interested botanists. This information, with supplementary data from overlooked specimens of earlier collectors, is here presented by families in Englerian sequence, with pertinent comments ...