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Woollyleaf bur ragweed (Ambrosia grayi)

Woollyleaf bur ragweed Common Names: Bur Ragweed, woollyleaf bursage, lagoonweed

Description: Native to the Great Planes States of Nebraska, Kansas, Colorado, New Mexico, Oklahoma, and Texas.

Habit: Perennial that reproduces by underground root-stocks and seeds and can reach a height of 3.9-11.8 inches. Roots can reach a depth of 15 feet.

Leaves: Alternate or opposite, broadly ovate, pinnately 3-5 parted or entire, long petioled, dusty white or green in color, 0.39-1.8 inches long.

Stems: Erect, growing 1-2 feet tall, branching from the base and covered with fine, woolly hairs.

Flowers: Male flowers are in small drooping heads at the top of plant while female flowers are in the axil of the leaves, usually one per leaf. Composite heads in short racemes.

Fruit and seeds: 3-7 mm long with hooked spines or curved at the tip.

Habitat: Native to northern Mexico. Can be found in roadsides, ditches, fields and wet areas.

Reproduction: By seed or underground root-stock.

Monitoring and rapid response: Prevent spread by cleaning harvesting and tillage equipment before leaving infested areas. Can be controlled using general use herbicides such as 2,4-D LVE, Dicamba, Glyphosate, Picloram and Imazapic.

Credits: The information provided in this factsheet was gathered from the Kansas Department of Agriculture, Nebraska Invasive Species Program and the Center for Invasive Species and Ecosystem Health.

Individual species images that appear with a number in a black box are courtesy of the network ( Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (

Common Name:

Woollyleaf bur ragweed

Scientific Name:

Ambrosia grayi







USDA Symbol: