Performance of the network in function of the phylogenetic relatedness of taxa used for training, validation, and testing. (a) Angiosperm phylogeny (modified from APG III, 2009) and diversity in the training set (full circles) and test set (open circles). The open diamond indicates the position within the angiosperm phylogeny of the taxa used for validation (Lannea species; see text). The numbers in the central frame denote the performance indices: precision, recall, and F‐score. Average precision, recall, and F‐score for the training set are 0.84, 0.91, and 0.87, respectively. Images (b, c, and d) visualize the performance of the network on unseen taxa belonging to the test set with (b) Cyrtorchis chailluana (Orchidaceae, Asparagales), (c) Lannea schweinfurthii (Anacardiaceae, Sapindales), and (d) Ipomoea eriocarpa (Convolvulaceae, Solanales). Green crosses denote the actual stomata, red x's the stomata recognized by the network with a confidence of 0.7 or higher. Color gradient from green (low confidence) to yellow (high confidence)