Arabidopsis thaliana (Mouse-ear Cress)

Plant Info
Also known as: Thale Cress
Family:Brassicaceae (Mustard)
Life cycle:annual
  • Weedy
Habitat:part shade, sun; sandy or gravelly soil, disturbed areas, along railroads, fields, woods, lawns, bluffs
Bloom season:April - May
Plant height:2 to 14 inches
Wetland Indicator Status:none
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

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Detailed Information

Flower: Flower shape: 4-petals Cluster type: raceme

[photo of flowers] Elongating cluster of stalked flowers at the ends of branching stems, with a few to several flowers open at the tip and fruit developing below. Flowers are about 1/8 inch across with 4 rounded white petals and 6 yellow stamens. The sepals behind the flower are about half as long as the petals and have a few hairs around the edges.

Leaves and stems: Leaf attachment: alternate Leaf attachment: basal Leaf type: simple

[photo of basal leaves] Leaves are primarily basal with a few leaves widely spaced on the stems. Basal leaves are 1 to 2 inches long, up to ½ inch wide, oblong to narrowly spatula shaped, with rounded tips, stiff hairs across the surface, toothless or with tiny teeth around the edges, narrowing at the base to a stalk. Basal leaves may wither away as the plant matures.

[photo of stem leaves] Stem leaves are about 1 inch long, up to 3/8 inch wide, tapering to a point at both ends, stalkless and mostly toothless. Stems are bristly hairy at the base and hairless in the upper plant. Multiple stems may arise from the base.

Fruit: Fruit type: capsule/pod

[photo of fruit] Fruit is a slender cylindrical pod up to ¾ inch long, spreading or angled up, sometimes curved up.


An interesting weed, chosen for plant study and experiments worldwide, even on the International Space Station, due to its extremely short life cycle and ease of propagation. It can go from seed to maturity in about 6 weeks, and easily colonizes when left to its own devices. It is similar in appearance to the native Lyre-leaved Rock Cress (Arabidopsis lyrata), which has larger flowers, lobed or divided basal leaves, narrower stem leaves, and does not form colonies. Mouse-ear Cress is no doubt under-reported in Minnesota.

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More photos

Photos by K. Chayka and Peter M. Dziuk taken at a nursury grower's plot in Pine County.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Elaine - East Gull Lake (S. Cass / Crow Wing counties)
on: 2012-05-27 12:08:59

This is currently blooming along the wooded paths serving Madden's Resort. I didn't know what it was so looked it up. Love this site for local identification use, thanks!

Posted by: Carrie Anne - Minneapolis, MN
on: 2013-10-04 19:04:57

Oh this makes me sad. Check out

"Last year, Don Wyse, an agronomy professor and researcher, knowing of David Marks’ expertise in Arabidopsis, suggested that his lab spend some time investigating pennycress – an all but unstudied plant with promising traits – as a possible cover crop and biofuel source. Wyse reasoned that Marks' substantial knowledge of Arabidopsis would translate well to the task of tapping the potential of pennycress. One thing led to another and soon plant biology graduate student Kevin Dorn, who is advised by Marks and Wyse, was involved in an effort to sequence the pennycress genome with the goal of improving pennycress."

Posted by: K. Chayka
on: 2013-10-04 19:44:26

Just what we need, more "crop improvement". There's the potential here to make what is now an occasional weed and turning it invasive. :-(

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