Hill mustard
(Bunias orientalis)
An herbaceous biennial that can act like a perennial in Wisconsin. Grows to be 1-4’ tall with warty bumps along stem as well as hairs on stem and leaves.
Overview
Other names for this plant include:- Common names: Turkish warty cabbage, Turkish rocket
- It invades grasslands, fields, pastures, roadsides and disturbed areas.
- Capable of invading high-quality areas and creating monoculture stands.
- Plants may contain allelopathic compounds (chemicals toxic to surrounding vegetation).
Classification in Wisconsin: Prohibited/Restricted (Restricted in Dane, Grant, Green, Iowa, Lafayette, and Rock counties; Prohibited elsewhere).
Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for hill mustard was based upon this literature review [PDF] developed by the department.
Identification
Leaves: Look similar to dandelion leaves; highly lobed, lance-shaped and covered with hairs. Leaves sometimes have warty texture as well. Basal leaves can be 12” or longer and get smaller as they move up the stem.
Flowers: Dense clusters of 4-petaled, yellow, fragrant flowers. Blooms in late spring. Flowers are self-fertile and hermaphroditic (containing both male and female organs).
Fruits & seeds: Oval or tear-shaped fruits are covered with warty bumps and contain 2-4 seeds.
Roots: Taproot at least 1” wide, generally in a cluster of roots. Extremely hard to pull or dig roots out.
Similar species: Hill mustard resembles yellow rocket (Barbarea vulgaris; non-native), but is easily distinguished by its stem texture and fruit. Yellow rocket is shorter, its stems do not have warty bumps and its fruits have narrow seed pods.
Control
Mechanical: Use tillage to dislodge root system. When flowers appear, mow as close as possible to ground to halt seed production. Continual mowing regimes may be needed as mowing once may result in greater seed production.
Chemical: Foliar spray with 2,4-D or metsulfuron before seed set.
For more information on control techniques, visit the Hill mustard factsheet [exit DNR] by University of Wisconsin-Extension.
Resources
Sources for content:- Renz, Mark J. and Jerry D. Doll. Hill Mustard, an invasive mustard on the move in Southwestern Wisconsin [exit DNR]. UW-Madison Extension.