Dogbane (Apocynum cannabinum) is the representative species for the dogbane family, Apocynaceae, which includes milkweeds and other plants that ooze milky sap ladened with poisonous alkaloids. Indeed, Apocynum translates to "poisonous to dogs," or "dog killer." Sap from the plant is reported to have been used against ravenous feral dogs. However, it apparently has no effect on werewolves; that's Wolfsbane (Aconitum spp., family Ranunculaceae). Yet another example of the value of knowing plant taxonomy and being able to make an accurate plant ID ... as though your life depended on it.
I recently came across two insects that specialize in feeding on dogbane. The so-called Dogbane Beetle (Chrysochus auratus) should be familiar to BYGL readers; we've reported on it in the past. However, the Dogbane Webworm (Saucrobotys futilalis) was totally new to me; I had never come across this caterpillar nor had I heard of it before.