On Rosa virginiana; or could be Rosa carolina; either way, an indigenous Rosa species.
On what I believe is a St Jonh's Wort/Hypericum
See also on neighboring St John's Wort: https://www.inaturalist.org/observations/214025938
On what I believe is a St Jonh's Wort/Hypericum
See also on neighboring St. John's Wort: https://www.inaturalist.org/observations/214025355
Rather beautiful lens-shaped galls on the garden plant that is in the previous observation -- the plant is a garden variety ornamental cultivar of a St. John's Wort.
More images made a couple days later are here:
Out of the ~40 Asclepias viridiflora plants I saw on the lower half of this bluff, all but 2 or 3 had this rust on them