1Pepperwort, Lepidium campestre, a plant of the family Brassicaceae (Cruciferae) once credited with great medicinal virtues (now rare, perhaps obsolete).
2Pennycress, Thlaspi arvense.
Origin
Late 16th century; earliest use found in John Gerard (c1545–1612), herbalist.
Definition of mithridate mustard in US English:
mithridate mustard
noun
1Pepperwort, Lepidium campestre, a plant of the family Brassicaceae (Cruciferae) once credited with great medicinal virtues (now rare, perhaps obsolete).
2Pennycress, Thlaspi arvense.
Origin
Late 16th century; earliest use found in John Gerard (c1545–1612), herbalist.