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. 2016Footnote 1).

Worldwide: Native to southeastern Europe and western Asia (USDA-ARS 2016Footnote 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 2016Footnote 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 2003Footnote 4, CABI 2016Footnote 3). Persists in alfalfa and summerfallow in North America (Vujnovic and Wein 1997Footnote 5).

General Information

Dalmatian toadflax was introduced into North America in the late 19th century as an ornamental (Vujnovic and Wein 1997Footnote 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 1997Footnote 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 1997Footnote 5). This combination of characteristics makes eradication difficult; some success has been found with biological control (Vujnovic and Wein 1997Footnote 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

Dalmatian toadflax (Linaria dalmatica) seeds
Dalmatian toadflax (Linaria dalmatica) seed
Dalmatian toadflax (Linaria dalmatica) seed showing bronze highlights
Dalmatian toadflax (Linaria dalmatica) seed
Dalmatian toadflax (Linaria dalmatica) seed, cross-section

Similar species

Similar species: Broomleaf toadflax (Linaria genistifolia) seeds
Similar species: Broomleaf toadflax (Linaria genistifolia) seeds
Similar species: Striped toadflax (Linaria repens) seeds
Similar species: Striped toadflax (Linaria repens) seeds
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