Weed Seed: Galega officinalis (Goat's rue)

Family

Fabaceae

Common Name

Goat's-rue

Regulation

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

Distribution

Canadian: Occurs in ON, QC (Darbyshire 2003Footnote 1, Brouillet et al. 2016Footnote 2).

Worldwide: Native to northern Africa, Europe, Türkiye and Pakistan (USDA-ARS 2016Footnote 3). Introduced in Canada, the United States, Argentina, Chile and New Zealand (CABI 2016Footnote 4).

Duration of life cycle

Perennial

Seed or fruit type

Seed

Identification features

Size

  • Seed length: 3.1 - 5.0 mm
  • Seed width: 1.5 - 2.2 mm
  • Seed thickness: 1.0 - 1.5 mm

Shape

  • Seed long oval with a side notch, compressed

Surface texture

  • Seed dull, slightly roughened

Colour

  • Most seeds are a dull greenish-yellow, some are reddish-brown

Other structures

  • Hilum is round and surrounded by a ring of raised tissue
  • Furrow evident between radicle and cotyledons

Habitat and Crop Association

Old fields, pastures, rangelands, grasslands, fencelines, shores, riverbanks, roadsides and disturbed areas (Darbyshire 2003Footnote 1, CABI 2016Footnote 4). Reported as a weed in alfalfa (Whitson et al. 2000Footnote 5).

General Information

Goat's-rue has a history of use as a bee plant, forage and medicinal plant (USDA-ARS 2016Footnote 3). It was initially introduced into Utah in the 1890s as a forage plant, but was found to contain an alkaloid toxic to livestock (Tingey 1971Footnote 6).

Since its introduction, this species has infested moist, waterlogged and acidic soils in pastures and old fields in Utah. It is proving difficult to eradicate in those habitats (Lasseigne 2003Footnote 7).

Similar species

Oriental goat's rue (Galega orientalis)

  • Oriental goat's-rue seed are a similar size, long oval shape and round hilum as goat's-rue.
  • Oriental goat's-rue seeds have a pointed base, glossy surface and a shallow or no radicle furrow. Goat's-rue seeds are dull with a round base and pronounced radicle furrow.

Photos

Goat's rue (Galega officinalis) seeds
Goat's rue (Galega officinalis) seed
Goat's rue (Galega officinalis) seed, hilum view

Similar species

Similar species: Oriental goat's rue (Galega orientalis) seeds
Similar species: Oriental goat's rue (Galega orientalis) seed