This milkweed volunteers in this same spot every year. It's covered in milkweed bugs, but no monarchs were apparent. Very urban area.
--Asclepias incarnata, Grandview Alley BNP
We spent well over an hour just circling around this patch of milkweed enjoying the abundance of pollinators and other insects. See the last image for a panorama of the patch which included a few hundred plants, up to 4 ft tall.
Asclepias L. (1753), the milkweeds, is a genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species. It previously belonged to the family Asclepiadaceae, but this is now classified as the subfamily Asclepiadoideae of the dogbane family Apocynaceae.