WILD SPECIES Cultivated radish or wild radish ( sativus) Wild radish () Mustard Family ()

DESCRIPTION These two radish species are herbaceous annuals (sometimes perennials) that frequently invade grasslands and open, disturbed areas, including roadsides. Wild radish, Raphanus raphanistrum, may also be found in wetland areas. Although both species grow wild and both are commonly called wild radish, Raphanus sativus is the (escaped) cultivated , while R. raphanistrum is its wild relative. (Sativus means “cultivated”in Latin.) Both species can grow to 3 feet or taller. The are erect, with branching stems that typi- cally give mature plants a bushy appearance.The leaves are alternate, with lower leaves pinnately Raphanus sativus compound. ANNUALS

REPRODUCTION IMPACT Raphanus sativus has 4-petaled flowers that Wild are capable of excluding native range from white to pink, and bloom mostly plant species. Both radish species are also agri- between April and June,or almost year-round in cultural weeds. R. raphanistrum seeds in large the East Bay.R. raphanistrum has 4-petaled pale quantities may be poisonous to livestock. yellow and white flowers with dark veins, and blooms later in the year. The flowers are polli- KEY FACTORS nated by bees and butterflies. Seed pods u High seed production. (siliques) are dark green or occasionally dark red, ribbed, and either smooth or downy. R. u Long seed dormancy. sativus may have only up to 5 seeds per pod,but R. raphanistrum pods contain up to 10 seeds. TREATMENT OPTIONS The seeds are dark, oval, and hard. u Pull individual plants by hand or with a Weed Wild radishes reproduce only by seed. Seeds Wrench before seed pods develop. Given the can remain viable for at least 5 years and report- stout taproot, it’s best to do this after a heavy edly up to 20 years. Seeds are generally rain. The taproots in mature plants make wind-dispersed, but are also spread by water hand removal more difficult. and machinery. Germination takes place in u Cut plants below the root crown with a pick or spring and fall. shovel before seed pods develop.

THE PLANTS: HOW TO REMOVE BAY AREA WEEDS 85 ACTS F P -U ISPOSAL OLLOW NTERESTING F seed and long high the seed production Given viability of wild radishes, to is important it check to times a year several site the to return germination. seedling for I the Mediterranean. to native are Radishes D be removed and bagged withseed should Plants from the site whenever feasible or composted will that be maintained area in a small on-site example,(for weeding). follow-up by Plants on-site. seed can be decompose left to without WEED WORKERS’ HANDBOOK WEED WORKERS’ wild radish if a radish wild covers it Some weed workers spray a 1 spray workers weed Some brush cut or Foliar spray. large area. It’s important to do the first mow- first the do to important area.large It’s develop. seed pods any before ing as Mow as feasible, ground the to close plants the as often resprout. percent solution of glyphosate on the leaves flowers. plant the before However, wild radishes are reportedly developing resistance . several to application Glyphosate might best be reserved for follow-up spot treatment. Mow Notes u u

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