Alternate name: Stinking Dog Fennel, Stinking Chamomile
Family: Asteraceae, Aster view all from this family
Description Introduced annual herb.
Habit: erect, branched stems, green becoming red; holding ferny foliage with a strong foul smell; taproot.
Height: 4-36 in (10-90 cm).
Leaf: alternate, very fine, feathery, compound; each blade to 2.5 in (60 mm) long and 1 in (25 mm) wide.
Flower: daisy-like, terminal, 3/4-1.25 in (18-35 mm) wide; 10-16 oval white rays, 3 small teeth; around a domed yellow center, 1/4-1/2 in (5-10 mm) wide.
Fruit: tiny dry seed, wrinkled and bumpy, 1/16 in (1-2 mm) long.
Warning The foliage that may cause skin irritation if handled.
Flower April to October.
Habitat Disturbed sites, clearings, fields, roadsides.
Range Native to Europe; introduced as an ornamental; now naturalized throughout North America, except for arctic Canada; found in all 50 states of the U.S.
Discussion Also known as: dog-fennel, mayweed chamomile, stinking chamomile, stinkweed. This plant is considered weedy and/or invasive throughout North America. It can cause severe dermatitus in humans, and the leaves are unpalatable to livestock.