Articles: PubMed:Evidence-based medicinal value of Rudbeckia hirta L. flowers. PubMed:Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides. PubMed:A new highly oxygenated pseudoguaianolide with 5-LOX inhibitory activity from Rudbeckia hirta L. flowers. PubMed:Indirect effects on mutualisms: parasitism of bumble bees and pollination service to plants. PubMed:Profiling the chlorogenic acids of Rudbeckia hirta, Helianthus tuberosus, Carlina acaulis and Symphyotrichum novae-angliae leaves by LC-MS(n). PubMed:Formation of UV-honey guides in Rudbeckia hirta. PubMed:Nonstomatal versus stomatal uptake of atmospheric mercury. PubMed:Growth and Landscape Performance of Ten Herbaceous Species in Response to Saline Water Irrigation. PubMed:Management of lesion nematodes and potato early dying with rotation crops. PubMed:Mercury accumulation in grass and forb species as a function of atmospheric carbon dioxide concentrations and mercury exposures in air and soil. PubMed:Monoclonal antibodies against an arabinogalactan-protein from pressed juice of Echinacea purpurea. PubMed:The Effect of Marigolds (Tagetes spp.) and Other Cover Crops on Pratylenchus penetrans and on Following Potato Crops. PubMed:The Potential of Thiarubrine C as a Nematicidal Agent against Plant- parasitic Nematodes. PubMed:The complex nature of the mechanism of toxicity of antibiotic dithiacyclohexadiene polyines (thiarubrines) from the asteraceae. PubMed:Plant regeneration from protoplasts of Dimorphotheca and Rudbeckia. PubMed:Flavonols: pigments responsible for ultraviolet absorption in nectar guide of flower. PubMed:Pigments of Yellow-Eyed Races of the Black-Eyed Susan (Rudbeckia Hirta). PubMed:Pigments of yellow-eyed races of black-eyed susan, Rudbeckia hirta.