Eupatorium serotinum Michx.

Late Boneset

Eupatorium serotinum plant

Family - Asteraceae

Stems - To 2m tall, pubescent above, glabrescent below.

Eupatorium serotinum stem

Leaves - Opposite, toothed, petiolate, acuminate, ovate to lanceolate, to +15cm long, 10cm broad, typically glabrous.

Eupatorium serotinum leaf

Inflorescence - Terminal corymbiform clusters with many flower heads. Flower heads with +/-15 flowers.

Eupatorium serotinum inflorescence

Involucre - +/-5mm long(tall). Phyllaries imbricate, obtuse or rounded, pubescent.

Eupatorium serotinum involucreInvolucre.

Ray flowers - Absent.

Disk flowers - Disk florets 9-15 per head. Corolla white to grayish-lavender, 5-lobed. Pappus of capillary bristles. Achenes black when mature.

Eupatorium serotinum flowersHeads.

Eupatorium serotinum flowersFlorets.

Flowering - August - October.

Habitat - Pastures, prairies, waste ground, disturbed sites, roadsides, railroads.

Origin - Native to U.S.

Other info. - One of the most common "weeds" in the state, this plant is a dominant presence of the landscape when in full bloom. It is a pioneering plant and thrives in areas which get cut or mowed on occasion. It is definitely the most common Eupatorium in Missouri.

Photographs taken off Hwy 60, Carter County, MO., 8-28-03 (DETenaglia); also near Fremont, MI, 9-22-2012 (SRTurner).