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 V. 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.