Thale cress
Arabidopsis thaliana
Description
A. thaliana is a small plant, 2 to 25 cm (1 to 9.5 in) in height, with a basal rosette of leaves that are 0.8 to 3.5 cm (0.3 to 1.3 in) long and up to 1 cm (0.4 in) wide; cauline leaves (on the flowering stem) are smaller. The small white flowers, which are less than 0.5 cm in diameter, have 4 petals and develops into a siliqua (a seed capsule or pod) that contains 20-30 small plump tan brown seeds, each 0.5 mm or less in diameter.