Lanceleaf Ragweed

Ambrosia bidentata Michx.

Asteraceae (Sunflower Family)

▲ ▼ mature plants

▲ mature plant

▲ ▼ stem, leaves and inflorescences

▲ inflorescence detail

Ambrosia bidentata Michx., Lanceleaf Ragweed: (Bayer Code: AMBBI; US Code AMBI2)

Is a moderately-branched native summer annual weed with upward-bent lance-shaped or narrowly 3-lobed leaves (2-3 feet tall)
Inflorescence is larger than common ragweed, and has downward-curving bracts between flower clusters in the spike (helps distinguish from annual marshelder, which has upward-pointing bracts between flowers in spike); also allergenic
Prefers moist soils, but may grow in any fertile soil

(Updated January 19, 2019)