Raphanus raphanistrum

Native to northern Africa, western Asia, Europe, and Macaronesia. Introduced and naturalized in North America.

Minnesota secondary noxious weed

Minnesota restricted weed seed

Fields, roadsides, disturbed areas.

June to August

Yellow, turning to white

12″ to 24″

This is a 12″ to 24″ tall, erect, annual forb rising from a small, thick taproot. Initially, there is a rosette of basal leaves. Later, a stem is produced.

The stems are branched in the upper portion and usually covered with firm, stiff hairs.

The basal leaves are up to 8 inches long and 2 inches wide. They are oblong, two to four times longer than wide, to inversely egg-shaped, attached to the leaf stalk at the narrow end. They are pinnately divided into 5 to 15 oblong lobes with the lower lobes very small, the upper getting progressively larger, the largest lobe at the end. The upper leaves are alternate, smaller, often unlobed, and attached to the stem on short leaf stalks. All leaves are covered with short, stiff hairs.

The inflorescence is a cluster of stalked flowers at the end of each stem and branch.

The flower is ½″ to ¾″ in diameter on ¼″ to ¾″ long flower stalks. The petals are 4-parted, yellow, and prominently veined, eventually turning to white. They narrow abruptly near the base to a long claw. The flower stalks become erect when the flower matures.

The flower is replaced by a single fruit, a 1-celled pod, ¾″ to 1¼″ long with a ⅜″ to 1″ long beak-like tip. It stands erect on the already erect flower stalk. It has two segments. The lower segment is short and does not bear seeds. The upper segment contains 4 to 10 seeds in a single row. It is thick and cylindrical when fresh, prominently ribbed and dented between the seeds when dry. To disperse its seeds it breaks into fragments between the 1-seeded segments.

Garden radish (Raphanus sativus) has pink or light purple flowers and a thicker taproot. The seed pods have 2 or 3 seeds.