Botanical name: Sisymbrium altissimum Family: Brassicaceae (Mustard family)
Tumble mustard is a broadleaf winter or summer annual and sometimes biennial plant with a highly branched top. Tumble mustard exists as a rosette until the flower stem develops at maturity. Leaves at the base of young winter rosettes are coarse and deeply lobed. Leaves near the top are smaller and deeply cut to form threadlike divisions. In mature plant, stems are erect and branched. The plant can reach a height of 5 feet. Leaves at the base of tumble mustard (rosette leaves) are coarse and deeply divided, or lobed to compound (fully divided into separate leaflets), have stalks, and are about 6 inches (15 cm) long. Upper leaves are stalkless, smaller than the lower leaves, deeply cut to form threadlike divisions, and do not clasp the stem. Long unbranched hairs sparsely cover leaves. Tiny, pale yellow (rarely white) flowers with four petals cluster on thick, spreading stalks are borne at the top. Tumble Mustard is found in Europe and temperate Asia. In India it is found in Jammu & Kashmir and Lahaul. Flowering: April-September.
Identification credit: Varun Sharma
The flower labeled Tumble Mustard is ...