UC IPM Online UC ANR home page UC IPM home page


SKIP navigation


How to Manage Pests

Identification: Weed Photo Gallery

Mayweed chamomile

Scientific name: Anthemis cotula (Sunflower Family: Asteraceae)

Click on image to enlarge

Life stages of Mayweed chamomile top picture bottom left picture bottom right picture

Mayweed chamomile, often called dog fennel, is an annual bushy broadleaf plant that germinates in early spring. In California it is found in the northwestern region, central-western region, central Sierra Nevada, Central Valley, South Coast, Transverse Ranges, and Peninsular ranges up to 6600 feet (about 2000 m). Mayweed chamomile inhabits agricultural land and other disturbed areas.


Coastal dunes, chaparral, woodlands, crop fields, orchards, vineyards, landscaped areas, gardens, roadsides and other disturbed, unmanaged sites.


Although they dry up rapidly and are seldom seen, the cotyledons (seed leaves) are oval, hairless, and small at roughly 1/10 to 1/3 of an inch (2.5–8 mm) in length. The leaves in the first leaf pair are opposite to one another along the stem and can be nearly hairless to hairy. Subsequent leaves are alternate to one another along the stem, are lobed to deeply divided, and nearly hairless to hairy.

Mature plant

Mayweed chamomile can have a spreading form or be an erect plant, reaching 6 inches to 3 feet (15–90 cm) long. Although similar looking to pre-flowering pineappleweed, Chamomilla suaveolens, and lesser swinecress, Coronopus didymus, mayweed chamomile can be distinguished by its more finely dissected leaves that appear to clasp the stem. Also crushed pineappleweed smells like pineapple whereas crushed mayweed's odor is unpleasant.


Flowering takes place from April to August. Tiny flowers cluster to form a daiseylike flowerhead with white flowers (ray flowers) circling a center of yellow flowers (disc flowers).


Fruit are single seeded, wedge shaped, and ribbed.


Mayweed chamomile reproduces by seed.

Related species/Similar looking plants

Lesser swinecress

More information

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2014 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/WEEDS/mayweed_chamomile.html revised: January 8, 2014. Contact webmaster.