Taxonomic signals in pollen amino acids: closely related species often have a similar chemistry. Each symbol denotes one plant species. Plants hosting oligoleges are displayed with « + » plants not known to host them with « o ». Species that plot together are similar in their relative proportions of amino acids (free and protein-bound pooled). Four examples of plant families are highlighted to indicate their similar pollen composition (NMDS, stress = 9.53, Bray-Curtis similarity).