This milkweed is perennial. Aphids really like it and often cover sections of the stem. It is a host for the Monarch caterpillar, Danaus plexippus (fourth photo). It also attracts the Queen butterfly, Danaus gilippus. It grows plentifully by the trail at the Silver Creek Fish Hatchery and is found sporadically in other locations. Tarantula hawks (middle left picture) like it too, so be careful.