Robuta

https://fsus.ncbg.unc.edu/main.php?pg=show-taxon-detail.php&taxonid=6349 Silphium asteriscus var. trifoliatum - FSUS silphium asteriscus var https://www.ideals.illinois.edu/items/10615 Conservation Assessment for Whorled Rosinweed (Silphium trifoliatum L.) | IDEALS conservation assessment silphium ideals https://species.wikimedia.org/wiki/Silphium_asteriscus_var._trifoliatum Silphium asteriscus var. trifoliatum - Wikispecies silphium asteriscus var wikispecies