Fig. 7. <i><b>Botrychium tenebrosum</b></i> from the second edition of <a href="//commons.wikimedia.org/wiki/Britton_%26_Brown,_Illustrated_Flora,_Second_Edition" title="Britton &amp; Brown, Illustrated Flora, Second Edition">An Illustrated Flora of the Northern United States, Canada and the British Possessions</a><i> (New York, 1913)<br>Syn. </i><a href="//commons.wikimedia.org/wiki/Botrychium_simplex" title="Botrychium simplex">Botrychium simplex</a><i> var </i>tenebrosum<i></i>
Nathaniel Lord Britton &amp; Addison Brown
1913
An Illustrated Flora of the Northern United States, Canada and the British Possessions, 2nd edition