Showy Tick Trefoil

Desmodium canadense

Margaret Melgaard, Wisconsin State Herbarium

Emmet J. Judziewicz, Wisconsin State Herbarium

Showy Tick Trefoil is a common wildflower with small pink flowers. It grows up to six feet tall, but is usually much shorter.

This plant blooms in July and August with large clusters of flowers, but it is probably best known for its seeds, which cling to people's socks and clothing.

Showy Tick Trefoil grows in fields, meadows, roadsides, shores, open woods, and edges.

Emmet J. Judziewicz, Wisconsin State Herbarium

Stan Malcom

The leaves of Showy Tick Trefoil are split into three leaflets. Leaflets are usually dark green and slender, growing up to three inches long.

Each pink (sometimes purple) flower is only 1/2 inch long, but they are always together in long clusters. Flowers have two petals which are important in pollination.

This plant has a special way to make sure it gets pollinated. When an insect, such as a bee or butterfly, lands on a flower to collect nectar, the two petals close on the insect and the flower shoots pollen on its body. The flower then relaxes and the insect is free to visit elsewhere.

Once a flower has been pollinated (received pollen from another flower), it dies and a fruit takes its place.

The fruits of Showy Tick Trefoil are hairy pods, split into triangle-shaped seeds. When an animal brushes against the plant, the hairs on the seed grab onto its fur. This way the seeds can travel to new places and grow new plants.

As the plant grows older, it leans over closer to the ground. This makes sure animals will be able to rub agains it.

Showy Tick Trefoil seeds grow quickly after fires. This plant is also perennial, meaning it grows back every year.

Showy Tick Trefoil is a host plant for the caterpillars of many butterfly species, including Silver-spotted Skipper, Clouded Sulphur, and Eastern Tailed Blue.

Small adult butterflies visit trefoil flowers for nectar, especially hairstreaks and coppers (two families of small butterflies). Bees also visit flowers for nectar and, as mentioned above, all of these insects help pollinate the flowers.

The seeds of Showy Tick Trefoil are eaten by Northern Bobwhite, Wild Turkey, Eastern Towhee, Dark-eyed Junco, Virginia Opossum, and White-footed Mouse.

White-tailed Deer eat leaves and stems.

Showy Tick Trefoil is helped by a bacteria called Rhizobium.

Stan Malcom

Relationships in Nature: 

Animals Using as Food Source

Animals Using as Shelter

Associations With Other Plants


Northern Bobwhite

Clouded Sulphur

Spotted Joe-pye Weed

Honey Bee Pa

Wild Turkey

Eastern Tailed Blue

Spotted Jewelweed

Golden Northern Bumble Bee Pa

Virginia Opossum

Silver-spotted Skipper

Common Milkweed

Eastern Tailed Blue Pa

White-footed Mouse

Common Mullein

Eastern Gray Squirrel D

White-tailed Deer

Common Ragweed

Eastern Chipmunk D

Clouded Sulphur


Virginia Opossum D

Eastern Tailed Blue

Common Dandelion

Striped Skunk D

Silver-spotted Skipper

Bracken Fern

Raccoon D

Honey Bee

Kentucky Bluegrass

Red Fox D

Golden Northern Bumble Bee

Lamb's Quarters

White-tailed Deer D

Pennsylvania Smartweed

Woodchuck D

White-footed Mouse D

Meadow Vole D

Eastern Cottontail D

Human D

Relationship to Humans:

People are very helpful to this plant when they brush up against it. Trefoil seeds cling very easily to socks and other clothing. This can be annoying to people when they have to pick the seeds (sometimes called "hitch-hikers") off. Showy Tick Trefoils provide great beauty on roadsides and in meadows.


Desmodium canadense


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