Latin Name: Linaria dalmatica
Physical Description: it is a perennial herb from a long creeping rhizome. Stems are erect, smooth, grow up to 1 m tall and secrete a milky substance when broken. Leaves are alternate, waxy, pointed at the tip and clasp the stem. Flower are reminiscent of a snapdragon with petals ranging from 2cm to 4cm long. Flowers are two-lipped, yellow, often with an orange bearded throat and long spur.
Habitat: it is commonly be found growing in fields, pastures, riparian areas, rangeland and disturbed sites such as roadsides, forest clearings and agricultural fields.
Impacts: it out-competes native plants and reduces the biodiversity of grasslands and forests. It reduces available foliage for livestock and wildlife and could pose toxicity issues if ingested.
Reproduction: it reproduces by seed and vegetatively through adventitious root buds. Fruits are 2 celled capsules with many irregularly-shaped black seeds. A single plan can produces up to 500,000 seeds per year. Roots can extend 3m deep and 3m laterally from the parent plant.
Mechanical: small populations can be controlled by pulling immature plants that have not yet established an extensive root system. Mowing will reduce the number of seeds but is not recommended as it can stimulate vegetative growth. Mechanical efforts require multi-year management efforts to deplete established seed banks.
Chemical: Several herbicides with the following active ingredients can control Dalmatian toadflax: 2,4-D, Glyphosate, Aminopyralid, Clopyralid, Picloram, Dicamba, Imazapyr, and Metsulfuron. For available products, contact your local agri-supply store. Prior to any herbicide application, read and follow the label instructions.
Biological: Several weevil species are established in British Columbia as biological controls:
- Brachypterolus pulicarius– seed feeding beetle
- Mecinus janthiniformis– stem mining beetle
- Rhinusa antirrhini– seed feeding beetle