Weed Seed: Abutilon theophrasti (Velvetleaf)

Family

Malvaceae

Common Name

Velvetleaf

Regulation

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

Distribution

Canadian: Occurs in all provinces except NL, NT, NU and YT (Brouillet et al. 2016^Footnote 1). Prevalent in southern ON and QC (Warwick and Black 1988^Footnote 2).

Worldwide: Native to Asia (India or China) and introduced to Europe, northern Africa and North America (CABI 2016^Footnote 3).

Duration of life cycle

Annual

Seed or fruit type

Seed

Identification features

Size

Seed length: 3.0 - 4.0 mm
Seed width: 2.3 - 3.6 mm

Shape

Heart-shaped seed with unequal lobes and a conspicuous notch at hilum end

Surface Texture

Seed dull with minute reticulations and scattered tubercles, concentrated at the hilum

Colour

Seed greyish brown with a lighter-coloured pubescence

Other Features

Flap-like tissue covering the hilum may be present

Habitat and Crop Association

Cultivated fields, field margins and fence rows, gardens, roadsides, vacant lots and other waste places. A troublesome weed, especially in corn, soybean, sorghum and cotton fields (Warwick and Black 1988^Footnote 2).

General Information

Velvetleaf was introduced into North America in the mid-1700s as a potential fibre crop (Warwick and Black 1988^Footnote 2).

This annual species is adapted to be a weed of cultivated land and waste places, and movement of feed grain is believed to have spread it throughout eastern Canada (Warwick and Black 1988^Footnote 2).

Similar species

Flower-of-an-hour (Hibiscus trionum)

Flower-of-an-hour seeds are a similar heart shape, brownish colour, minutely reticulate surface and tissue covering the hilum as velvetleaf.
Flower-of-an-hour seeds (length: 2.5 mm; width: 2.3 mm) are generally smaller than velvetleaf, densely covered with tubercles made up of brown hairs and resin glands, the surface is dark brown, and the lobes of the seed are equal or subequal. Velvetleaf seeds have fewer tubercles, the surface is light greyish-brown and the lobes are unequal.