Wild radish  (Raphanus raphanistrum)

Wild radish is a winter or summer annual, or sometimes a biennial broadleaf. In California both wild radish and radish, Raphanus sativus, are widespread and where they occur together they readily hybridize. The resulting offspring pose a problem for identification to species because of the range of characteristics they exhibit. Wild radish is found throughout California except for deserts, up to 2600 feet (800 m) and radish is found throughout except for deserts, the Great Basin, and some mountain areas, to 3300 feet (1000 m). Both are susceptible to several diseases and pests that damage a variety of crops. These pests include flea beetle, thrips, blackleg of brassicas, and turnip yellow mosaic tymovirus (TYMV). They also attract several beneficial predators of crop pests, as well as bees. Wild radish can be found in agricultural fields and other disturbed sites.

Habitat

Crop fields, orchards, vineyards, neglected gardens, parks, roadsides, and other disturbed locations.

Seedling

Cotyledons (seed leaves) are kidney to broadly heart shaped, about 2/5 to 4/5 inch (1–2 cm) long, with a deep notch at the tip and a base that abruptly tapers to a hairless stalk. Leaves are alternate to one another along the stem. The seedlings resemble mustards in the genus Brassica but are duller green and more roughly textured. Both the first true leaves and a few later leaves have a long football shape, a base that tapers or is deeply lobed once or twice, irregularly round-toothed edges, and attach to the stem on long stalks. Both the first true leaves and later few leaves have a long football shape, a base that tapers or is deeply lobed once or twice, irregularly round-toothed edges, and are attached to the stem with long stalks.

Young plant

Plants exist as rosettes until the flower stem develops at maturity.

Mature plant

Mature plants are erect, up to 2 feet (1.2 m) tall, and usually branch in the upper portion. Leaves vary in size and shape, but are usually sparsely covered with stiff, flattened hairs, especially toward the base. Lower leaves range from football to egg shaped, deeply lobed (but sometimes weakly lobed) to deeply divided into leaflets, have irregularly round edges or sharp toothed edges, and are typically 2-1/3 to 8 inches (6–20 cm) long. Upper leaves are reduced in size, football shaped, toothed, sometimes lobed at the base, and either stalkless or on a short stalk.

Flowers

Flowers have four petals that are narrowed at the base, are generally 3/5 to 1 inch (15-25 mm) long, and may have dark violet veins.

• Wild radish flowering takes place from April through July. Flower petals range from white to a faded yellow, or pale purplish pink.
• Radish flowering takes place from February through July. Flower petals are usually pale purplish-pink and occasionally, white.

Hybridized populations usually exhibit many flower colors, from white to purple to pink or light yellow brown with streaks of different colors.

Fruits

Seedpods are initially fleshy and with time become dry and corky. They are long and narrow, almost straight, roundish in cross-section, with a pointed tip. The pods do not open to release seed.

• Wild radish: Seedpods are mostly 1-3/5 to 3-1/6 inches (4–8 cm) long and 1/6 to 1/4 of an inch (4–6 mm) wide, with a nearly uniform diameter for most of the length, and a beak about 2/5 to 4/5 of an inch (1–2 cm) long. Dry pods are noticeably constricted between seeds.
• Radish: Dried seedpods have straight sides or may have slight constrictions between seeds. The diameter is largest below the middle and tapers toward the end of the pod.

Seeds

Seed are round to egg shaped, from less than 1/10 of an inch up to 1/6 of an inch (2–4 mm) long and roughly 1/12 of an inch (2 mm) wide. They are brown, reddish brown, or yellowish brown.

Reproduction

Reproduces by seed.

Related or similar plants

• Cultivated radish, Raphanus sativus

More information

• Broadleaf ID illustration
• Wild radish Calflora's distribution map
• Radish Calflora's distribution map
• For agriculture: UC IPM Pest Management Guidelines