Dogfennel , Dog Fennel

Eupatorium capillifolium (Lam.) Small

Asteraceae (Sunflower Family)


Dogfennel is a native, warm season, rhizomatous perennial plant. As an erect plant, it can grow up to 3 meters in height. The leaves are divided into several thread-like segments and are one or two pinnately divided. The upper stem leaves may be entire or not divided. Dogfennel has a pappus (i.e., a ring of fine, feathery hairs surrounding composite plants) containing 20 to 30 bristles. Heads are in dense, paniculiform (i.e., resembling a panicle with a branching inflorescence) arrays.    Bloom time occurs from August to October. The flowering heads occur as elongated leafy, branched, or wand-like heads. The phyllaries subtending the flowers are hairless and in various lengths. The phyllaries are mostly green with whitish margins. The numerous tiny flowers are white. The seeds are very small and measure about 1 mm in length. Seedlings emerge from spring to early autumn. Plants will re-sprout from broken stems.     Dogfennel has little to no value for livestock and wildlife use and is usually considered a pest plant. Cattle graze it sparingly, if at all, even when other forage is scarce.  


Found growing in unimproved pastures, old fields, open sites, roadsides, wooded sites, and disturbed sites with sandy soils. Dogfennel grows quickly in moist, well-drained soils with full sun to part shade. It tolerates most soil types including dry, sandy soils. Drought tolerant.