(Before 1980) This plant is a yellow-flowered selection from a swarm of natural hybrids on the Choptank River located on the Maryland/Delaware River. The two species that have hybridized are periclymenoides and atlanticum. Our plant is located just north of R. calendulaceum, in the area containing the Hemlock grove, in a section (now obscured) that was rock-lined to enclose a planting of azaleas.