Dalmation Toadflax

Description

Dalmatian toadflax is a perennial forb with a large taproot, waxy, fleshy leaves, and a showy spike of bright yellow flowers.

Type

Perennial

Habitat & Impacts

It can grow in a wide range of habitats from gravelly, disturbed roadsides to open forests. Infestations of Dalmatian toadflax can reduce forage quality and quantity for livestock and can reduce native vegetation cover in areas of severe infestation. Toadflax can displace sod-forming or bunchgrasses and increase soil erosion, surface runoff, and sediment production (Lajeunesse 1999). Cattle may occasionally graze toadflax flower stalks, but this may lead to mild poisoning and usually, cattle avoid this species. Sheep will graze toadflax without apparent ill effect.

Method of Spread

Dalmatian toadflax reproduces by seed or can spread vegetatively from the roots. Each plant can produce a very large number of seeds, up to 500,000 per plant, but most seeds land close to the parent plant (Robocker 1970). However, birds and mammals may eat Dalmatian toadflax seedheads and spread seeds a considerable distance. Dalmatian toadflax seeds may remain viable in the soil for up to ten years. Dalmatian Toadflax can also spread by creeping roots.

Location

Throughout the region except for the Coast and Nazko. Scattered throughout the Chilcotin, and heavily present in the Tatlayoko Valley.

Mechanical

Mechanical treatments consist of: Cutting plants prior to seed set to control seed production, repeated disking or tilling in cultivated fields over several years to reduce or eliminate infestations in cultivated fields or hand pulling prior to seed set to control small infestations.

Chemical

Chemical treatments in the Cariboo Chilcotin Coast consist of a fall application of picloram or picloram/2,4-D to control toadflax infestations in areas that do not have a successful bioagent catch. Dichlorprop may also be used in this region.

Biological

Mecinus janthinus, a stem weevil has been used with great effectiveness in the Cariboo. Many sites in the region have declined or been eliminated in recent years due to the successful establishment of the biocontrol agent. There are areas in the region, particularly the Chilcotin, where biocontrol agent releases in the past were not successful. A large biocontrol release in 2007 is being monitored in the Tatlayoko Valley and the management strategy will be re-evaluated if biocontrol proves unsuccessful. Other seed eating biocontrol agents are being developed.

CCCIPC Priority & Treatment Strategy

Priority 1 (new invader) in Nazko and Central Coast.

Priority 2 in Chilcotin (containment).

Priority 4 for all other areas (biocontrol)

Local Level

Handpull or cut.

Landscape Level

Biocontrol releases, and chemical treatment on localized areas such as private land.