Figure 1 from: Robinson H, Yankowski S (2016) The Taxonomic Significance of ducts in the corolla lobes of Vernonia (Vernonieae: Asteraceae). PhytoKeys 58: 1-7. https://doi.org/10.3897/phytokeys.58.7009

Figure 1 - A–D: A, B, Vernonia noveboracensis cross-sections of corolla lobes, outer surface upward C longitudinal section of corolla lobe showing multiple ducts D corolla lobe from specimen in preservative showing only poorly defined partitions between ducts E Vernonia angustifolia, corolla lobe from freshly collected specimen showing fresh resin in ducts F Vernonanthura brasiliana, corolla lobe from dried herbarium specimen showing solidified contents of ducts with walls over-lying cell layer G Vernonia echioides, part of corolla lobe from dried herbarium specimen showing some short-stalked capitate glands H Vernonia incana, part of corolla lobe from dried herbarium specimen.