Seed Study - Identifying Non-Native Forb Seedlings

Species: Amaranthus blitoides (Amaranthus graecizans)
Common name:
prostrate pigweed

Seedling Identification: Bright green spatulate leaves are hairless but glandular and thickened. Leaves are very crowded on a short stem.

Species: Chenopodium spp.
Common name: common lambsquarters, arid land goosefoot

Seedling Identification: Cotyledons and first true leaves sparkle with a coating that looks like tiny water droplets. Stems are purple and often leaves also are tinged with purple. C. album (common lambsquarters; exotic) and C. desiccatum (arid land goosefoot; native) were both found in the study plots, and the seedlings look very similar.

Species: Convolvulus arvensis
Common name: field bindweed

Seedling Identification: Cotyledons are dull green, fairly long and narrow. First true leaves are hastate and often have a reddish tinge at the base of the leaf. True leaves are similar to Polygonum convolvulus.

Species: Cynoglossum officinale
Common name: houndstongue

Seedling Identification: Cotyledons are large and very rounded. The first true leaves are softly pubescent, gray green and rolled at emergence.

Species: Leonurus cardiaca
Common name: motherwort

Seedling Identification: First true leaves are ovate with later leaves being very lobed (almost maple shaped). The leaves all have extremely irregular venation, and barb-like hairs on the upper and lower surfaces. The hairs tend to be more concentrated on the prominent mid veins on the backs of leaves.

Species: Marrubium vulgare
Common name: white horehound

Seedling Identification: Cotyledons are rounded and pubescent. True leaves wrinkled, distinctly veined and covered with whitish pubescence.

Species: Onopordum acanthium
Common name: Scotch thistle

Seedling Identification: Beware of confusing this one (in the seedling stage) with the native thistle Cirsium undulatum. There is no reliable way to differentiate between the species until the plants get some size and age.

Species: Sisymbrium altissimum
Common name: tumble mustard, Jim Hill mustard

Seedling Identification: Rosette with lobed leaves, that is very typical looking for the mustard family.

Species: Trifolium repens
Common name: white clover

Seedling Identification: Stems red and leaves dull green. First true leaves are rounded and come singly.

Species: Verbascum thapsus
Common name: common mullein

Seedling Identification: Rounded oval cotyledons. The first primary leaves are more ovate yet still rounded with soft venation and fine pubescence.

Last updated: April 10, 2015

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