Weed Seed: Linaria dalmatica (Dalmatian toadflax)

Family

Plantaginaceae

Common Name

Dalmatian toadflax

Regulation

Primary Noxious, Class 2 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.

Distribution

Canadian: Occurs in AB, BC, MB, NB, NS, ON, QC, SK and ephemeral in NL and YT (Brouillet et al. 2016^Footnote 1).

Worldwide: Native to southeastern Europe and western Asia (USDA-ARS 2016^Footnote 2). Introduced in North America, Argentina, South Africa, India, Australia, and beyond its native range in Europe (Germany, Hungary, Italy, Switzerland and the United Kingdom) (CABI 2016^Footnote 3).

Duration of life cycle

Perennial

Seed or fruit type

Seed

Identification features

Size

• Seed length: 1.0 - 2.0 mm
• Seed width: 1.0 -1.5 mm

Shape

• Seed rectangular-blocky

Surface Texture

• Seed covered in ridges that form a wavy-wrinkled pattern

Colour

• Seed black with bronze highlights

Other Features

• The seed edges are winged, approximately 0.2 mm wide

Habitat and Crop Association

Old fields, pastures, gardens, vineyards, forest plantations, roadsides, railway lines and disturbed areas (Darbyshire 2003^Footnote 4, CABI 2016^Footnote 3). Persists in alfalfa and summerfallow in North America (Vujnovic and Wein 1997^Footnote 5).

General Information

Dalmatian toadflax was introduced into North America in the late 19th century as an ornamental (Vujnovic and Wein 1997^Footnote 5). It is adaptable to a wide range of environmental conditions and soil types, but is mostly found on coarse soils in sparsely vegetated sites (Vujnovic and Wein 1997^Footnote 5).

Dalmatian toadflax is a perennial species that produces large numbers of seed every year (up to 400,000 per plant) and can also regrow from root pieces (Vujnovic and Wein 1997^Footnote 5). This combination of characteristics makes eradication difficult; some success has been found with biological control (Vujnovic and Wein 1997^Footnote 5).

Similar species

Broomleaf toadflax (Linaria genistifolia)

• Broomleaf toadflax seeds are a similar size, blackish colour, rough surface and sharp winged edges as Dalmatian toadflax.
• Broomleaf toadflax seeds have a silvery-blue sheen, have one tapered end and the winged edges have a microscopic reticulate pattern compared to Dalmatian toadflax.

Striped toadflax (Linaria repens)

• Striped toadflax seeds are a similar size, dark colour and rough surface as Dalmatian toadflax.
• Striped toadflax seeds lack winged edges, have a dull brownish surface and granular edges compared to Dalmatian toadflax.

Photos

Similar species