HPIPM:Pineappleweed

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Asteranae
Order	Asterales
Family	Asteraceae
Subfamily	Asteroideae
Tribe	Anthemideae
Subtribe	Matricariinae
Genus	Matricaria

Scientific Name

Matricaria discoidea

Scientific Name Synonyms

Lepidotheca suaveolens

Chamomilla suaveolens

Common Name

pineapple-weed

Pineappleweed (Matricaria discoidea)

Compiled by Melissa Graves, and Marjolein Schat, Montana State University from the following sources:

http://plants.usda.gov/java/profile?symbol=MADI6

http://www.illinoiswildflowers.info/weeds/plants/pineapple_weed.htm

Identification and Life Cycle

Pineappleweed (Matricaria discoidea), also called disc mayweed, is an annual in the sunflower (Asteraceae) family. Mature pineappleweed is 3 to 12 inches high. The small, yellowish green flowers at the ends of stems do not have showy petals. The foliage of pineappleweed is finely divided and gives off a strong, pineapple odor when crushed. Seedlings have opposite, bright green, narrow leaves with a pair of lobes near the base. Later leaves are alternate and fern-like, several times divided into narrow, fingerlike lobes.

Habitats

Habitats include stony slopes of pastures, barnyards, edges of driveways and sidewalks, gravelly areas along railroads and roads, and sunny waste areas that are rocky or gravelly. Disturbed areas are strongly preferred.

Impacts

Pineappleweed occurs in cereal and broad-leaved arable crops. This species is also a frequent weed of intensive vegetable cropping systems.

Biology and Ecology

Pineappleweed typically flowers from June to September, but flowering can occur as late as November. Seed set begins in July, normally within 40-50 days of flowering. Seed production per plant can average from 850 to 7,000 seeds. Seed germination is determined by availability of light, with a small amount being sufficient. Seed sown in cultivated fields emerges between February and November, with peak germination periods from March to May and August to October. Plants emerging between January and April have a longer vegetative period prior to flowering than plants emerging from mid-May to mid-July. Plants emerging after August will typically overwinter as vegetative rosettes and will flower the following spring. Earlier flowering plants set seed and die before winter. Flowering of pineappleweed is determined by day length, with shorter days contributing to a delay in the flowering period.

Biological Control

There are no biological control agents available for pineapple weed.

Mechanical and Cultural Control

Seedlings and larger plants should be controlled by cultivation to prevent seeding. Pineappleweed seedlings are more numerous on tine-cultivated or no-till land than ploughed land.

Chemical Control

There are a number of chemical control options for pineappleweed.

Consult herbicide labels for additional rate, application, and safety information. Additional herbicide information can be found at http://www.greenbook.net.

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.

References

For more information and images please visit IPM Bugwood: http://www.ipmimages.org/search/action.cfm?q=pineappleweed&Start=1&results=16