a genus of the mustard family having white or yellow or purplish flowers; closely related to genus Arabis
"The researcher decided to use Arabidopsis as a model organism because its small, white-flowered plants are closely related to the familiar garden plant known as Arabis."
Any cress (or related plant) of the genus Arabidopsis
"Researchers often use arabidopsis as a model organism to study how plants respond to drought stress in controlled laboratory settings."