A graphic chart with 11 species of lichen
<bdi><a href="https://en.wikipedia.org/wiki/en:Ernst_Haeckel" class="extiw" title="w:en:Ernst Haeckel"><span title="German biologist, naturalist, philosopher, physician, and artist (1834-1919)">Ernst Haeckel</span></a>
</bdi>
published 1920
<i>The Encyclopedia Americana</i>, v. 17, 1920, between pp. 398 and 399; see also <i>Kunstformen der Natur</i> (1904), plate 83: Lichenes (see <a rel="nofollow" class="external text" href="http://caliban.mpiz-koeln.mpg.de/haeckel/kunstformen/high/Tafel_083_300.html">here</a>, <a rel="nofollow" class="external text" href="http://caliban.mpiz-koeln.mpg.de/haeckel/kunstformen/high/Tafel_083_schema_300.html">here</a>, <a rel="nofollow" class="external text" href="http://caliban.mpiz-koeln.mpg.de/haeckel/kunstformen/high/Tafel_083_text_1_200.html">here</a> and <a rel="nofollow" class="external text" href="http://caliban.mpiz-koeln.mpg.de/haeckel/kunstformen/high/Tafel_083_text_2_200.html">here</a>)