Globe-podded whitetop (Cardaria pubescens), lenspod whitetop (C. chalapensis), and heart-podded whitetop (C. draba) are three closely related exotic mustards often referred to collectively as 'whitetop.' Whitetop is sometimes called hoary cress. All three whitetop species have small white flowers with four petals and six stames and grayish-green, arrowhead shaped leaves that clasp around the stem at their base. Whitetop is well adapted to moist habitats, especially sub-irrigated pastures, hay fields, rangeland, roadsides, and ditch banks. Whitetop also invades cropland, especially alfalfa. Successful management of whitetop requires the use of integrated weed management strategies. This includes combining strategies to prevent the movement of these weeds, containing existing infestations, and integrating control methods to reduce weed infestations to tolerable levels.