Synonyms for Milkweed (same or very similar meaning)
WordNet sense 1 (any of numerous plants of the genus Asclepias having milky juice and pods that split open releasing seeds with downy tufts):
silkweedWordNet sense 2 (annual Eurasian sow thistle with soft spiny leaves and rayed yellow flower heads):
Sonchus oleraceusFrom the ODE community, based on WordNetadd/edit