Plant Profile: Rorippa sylvestris L.

Yellow fieldcress, a member of the Brassicaceae family, is a persistent weed characterized by its creeping, fleshy white roots that generate numerous new plants. The flowers of this species are yellow. It can propagate through small root fragments, measuring under an inch, which may become entangled in the roots of nursery plants. It is believed to have been brought over from the Netherlands alongside herbaceous perennials, particularly hostas and daylilies. To distinguish yellow fieldcress from similar species, one should examine the roots. Both marsh yellowcress and southern yellowcress develop a white taproot but do not have the horizontal, spreading roots typical of yellow fieldcress. In the case of very young plants, it can be challenging to tell these three species apart until they grow large enough to exhibit the creeping roots. In terms of vegetative characteristics, yellow fieldcress leaves are generally more finely divided and have more pointed lobes along the edges compared to marsh yellowcress. However, these leaf traits can vary significantly and should not be solely relied upon for accurate identification. The seed capsules of marsh yellowcress are shorter and thicker, measuring less than half an inch, in contrast to those of yellow fieldcress. As yellow fieldcress is a perennial, most preemergence herbicides are ineffective against it; therefore, it is essential to remove any infested plant material to prevent further spread.