Keywords: Silphium asteriscus-linedrawing.png Silphium asteriscus An illustrated flora of the northern United States Canada and the British Possessions Courtesy of Kentucky Native Plant Society 1913 Nathaniel Lord Britton 1859-1934 and A Brown PD-old-auto-1923 1934 Britton Brown Illustrated flora of the northern states and Canada Silphium asteriscus Silphium - botanical illustrations |