Common alder tree, Alnus surrulata, and black alder, Alnus glauca
© Science & Society
Leaves, aments and seed of the common alder tree, Alnus surrulata, and black alder, Alnus glauca. Handcolored stipple engraving from a botanical illustration by Pancrace Bessa, engraved on copper by Gabriel, from Francois Andre Michaux's North American Sylva Philadelphia, 1857. French botanist Michaux (1770-1855) explored America and Canada in 1785 cataloging its native trees.