Dogfennel

eupatorium capillifolium

Dogfennel is a tall, aggressive perennial herb native to the eastern and southern United States. While often classified as a weed due to its rapid colonization of disturbed pastures and agricultural land, this plant plays a unique role in local ecosystems and boasts a striking, ethereal aesthetic. The plant has a pungent, dill-like aroma when crushed, which serves as a natural deterrent against many generalist herbivores.

Habitat: Commonly found in disturbed fields, pastures, roadsides, and pine flatwoods, preferring sandy, well-draining soils.

Appearance

Dogfennel is easily identified by its towering height, often reaching 1 to 3 meters, and its incredibly fine, thread-like leaves that give the plant a soft, feathery appearance. The stems are stout, hairy, and woody near the base, turning reddish-purple as the plant matures. In late summer and autumn, the upper branches erupt with thousands of tiny, cream-colored to greenish-white flower heads clustered in massive, plume-like panicles.

KingdomPlantaePhylumTracheophytaClassMagnoliopsidaOrderAsteralesFamilyAsteraceaeGenusEupatorium

Dogfennel

Interesting facts

Despite its name and feathery appearance, dogfennel is a member of the aster family and is not closely related to true culinary fennel.

Historically, pioneers stuffed their mattresses with dried dogfennel to repel bedbugs and fleas.

The toxic alkaloids in dogfennel can cause severe liver damage to cattle and horses if they are forced to graze on it when other forage is scarce.

Special abilities

Produces pyrrolizidine alkaloids, toxic compounds that deter livestock and most insects from feeding on its tissues.

Generates thousands of lightweight, wind-blown seeds per stem, allowing it to quickly colonize open areas.

Emits strong essential oils when damaged, which historically have been used to repel fleas and other biting insects.

Measurements & details

Length: 100-300 cm
Lifespan: 2-5 years

Diet & Feeding

As a photosynthetic plant, dogfennel synthesizes its own energy from sunlight, carbon dioxide, and water while absorbing essential minerals through its root system.

Primary Foods

Sunlight
Water
Carbon Dioxide
Soil Nitrogen
Phosphorus

Ecological connections

eaten by

Scarlet-bodied Wasp Moth

Cosmosoma myrodora

Male moths feed on the fluids of dogfennel to acquire defensive chemicals, which they then transfer to females during mating for egg protection.

mutualism

Western Honey Bee

Apis mellifera

Attracted to the massive late-season blooms for crucial fall nectar reserves.

Traits

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Also known as

No aliases listed yet.

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How long is Dogfennel?

100-300 cm

How long does Dogfennel live?

2-5 years

What does Dogfennel eat?

As a photosynthetic plant, dogfennel synthesizes its own energy from sunlight, carbon dioxide, and water while absorbing essential minerals through its root system.

Where is Dogfennel usually found?

Commonly found in disturbed fields, pastures, roadsides, and pine flatwoods, preferring sandy, well-draining soils.