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Publication #SP 37

Mexican-tea, Chenopodium ambrosioides L.1

D. W. Hall, V. V. Vandiver, and J. A. Ferrell2

Classification

Common Name: Mexican-tea

Scientific Name: Chenopodium ambrosioides L.

Family: Chenopodiaceae, Goosefoot Family

Seedling

The stem is pink (Figure 1). The cotyledon blades are ovate and green on both surfaces, or tinged pink on the lower surfaces. The first two leaves are opposite, while the subsequent leaves are alternate.

Figure 1. 

Seedling, Mexican-tea, Chenopodium ambrosioides L.

Mature Plant

Mexican-tea is a strong scented herb which may be annual or perennial (Figure 2). Its growth can be erect or ascending, up to 1 m tall. The stems and branches may be smooth or minutely hairy. The leaves are alternate, oblong to ovate or lanceolate in shape, and contain varying numbers of small dots which are glands. The margins may be wavy or toothed. The leaf size is gradually reduced upward on the plant. The flowers occur in clusters on spikes, with the upper spikes in a branched arrangement. The leaves may or may not be present on the spikes. The calyx is about 1 mm long, usually glandular, and completely encloses the fruit which is small, bladder-like and 1-seeded. The seeds are nearly black, similar to C. album but smaller (0.6-0.8 mm in diameter). Taxonomically, C. ambrosioides can be separated from C. album by the presence of hairs or glands. C. album can be separated by the presence of waxy particles which are absent on C. ambrosioides.

Figure 2. 

Mature plant, Mexican-tea, Chenopodium ambrosioides L.

History

The Greek word Chenopodium means "goose" and "foot," which refer to the shape of the leaves of some species. The Greek and later Latin species name ambrosioides means that this plant resembles some species of Ambrosia.

Habitat

This weed occurs in waste areas, cultivated lands and disturbed sites throughout Florida, northward to Maine and Ontario, and westward from Florida to Texas and California. This plant is native to the West Indies, Mexico, Central and South America and is naturalized in Europe, Asia, Africa and North America.

Biology

This plant has a very disagreeable odor. It will bloom and fruit when only 4 cm tall or can reach its maximum height of 1 m tall before flowering and fruiting.

Footnotes

1.

This document is an excerpt from Weeds in Florida, SP 37, a publication of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: May 1991. Revised: February 2006. Reviewed: February 2009. Please visit the EDIS Website at http://edis.ifas.ufl.edu.

2.

David W. Hall, former extension botanist, Herbarium, Florida Museum of Natural History; Vernon V. Vandiver, associate professor emeritus, Agronomy Department, Jason A. Ferrell, assistant professor, Agronomy Department; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.