bladder worm: encysted saclike larva of the tapeworm
larva: the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose
musk thistle: Eurasian perennial naturalized in eastern North America having very spiny white cottony foliage and nodding musky crimson flower heads; valuable source of nectar