About Eupatorium capillifolium (Lam.) Small
Eupatorium capillifolium (Lam.) Small, commonly called dog fennel or dogfennel, is a North American perennial herbaceous plant in the family Asteraceae, native to the eastern and south-central United States. It typically grows between 50 cm and 2 meters tall, producing several stems that fork from a large, substantial base. The stems and base are covered in highly dissected leaves that resemble branching green threads that grow from the stem in fractal patterns. When crushed, the leaves release a sour odor similar to dill pickles, while the flowers have a subtle floral scent. Dog fennel contains pyrrolizidine alkaloids, compounds that can cause liver failure. This species thrives on roadsides, in fields and reduced tillage crops, and in areas that have burned or otherwise been disturbed. It grows in the early to middle (seral) stages of ecological succession. Its native range covers the southern and eastern United States, extending from Massachusetts south to Florida, and west to Missouri and Texas; it is also native to Cuba and the Bahamas. Unlike other insect-pollinated species in its genus, E. capillifolium is wind-pollinated. Mature scarlet-bodied wasp moths (Cosmosoma myrodora) native to Florida eat dog fennel, storing the plant's toxins to protect themselves from predators. An essential oil extracted from Eupatorium capillifolium has anti-fungal properties.
