Fig. 23. <i><a href="//commons.wikimedia.org/wiki/Woodsia_ilvensis" title="Woodsia ilvensis">Woodsia ilvensis</a></i> from the second edition of <a href="//commons.wikimedia.org/wiki/Britton_%26_Brown,_Illustrated_flora_of_the_northern_states_and_Canada" title="Britton &amp; Brown, Illustrated flora of the northern states and Canada">An Illustrated Flora of the Northern United States, Canada and the British Possessions</a><i> (New York, 1913)</i>
Nathaniel Lord Britton &amp; Addison Brown
1913
An Illustrated Flora of the Northern United States, Canada and the British Possessions, 2nd edition