Sh-Z

Weeds: Shepherd’s-purse – Capsella bursa-pastoris

Weeds: Shepherd’s-purse – Capsella bursa-pastoris Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 03:09 Scientific name: Capsella bursa-pastoris Family: Brassicaceae (Cruciferae) Cycle: Annual Plant type: Broadleaf Shepherd’s-purse flowers and fruits Photo by: T.W. Miller Biology Shepherd’s-purse is an annual or winter annual (sometimes a biennial) plant with a thin taproot. The leaves are primarily in […]

Shepherd's-purse flowers and fruits.

Weeds: Smartweeds – Polygonum spp.

Weeds: Smartweeds – Polygonum spp. Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 06:58 Scientific name: Polygonum spp. Family: Polygonaceae Cycle: Annual/Perennial Plant type: Broadleaf Smartweed leaves Photo by: J.A. Kropf Biology Smartweeds are typically annual weeds with erect or spreading stems up to 3 feet long. The leaves are alternate, attaching to the erect or […]

Smartweed leaves.

Weeds: Sowthistle, annual and perennial – Sonchus oleraceus, Sonchus arvensis

Weeds: Sowthistle, annual and perennial – Sonchus oleraceus, Sonchus arvensis Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 08:43 Scientific name: Sonchus oleraceus, Sonchus arvensis Family: Asteraceae (Compositae) Cycle: Annual Plant type: Broadleaf Annual sowthistle flower heads Photo by: T.W. Miller Biology Annual sowthistle grows upright and can reach from one to four feet tall. […]

Annual sowthistle flower heads.

Weeds: Speedwells – Veronica spp.

Weeds: Speedwells – Veronica spp. Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 09:20 Scientific name: Veronica spp. Family: Scrophulariaceae Cycle: Annual/Perennial Plant type: Broadleaf Speedwell foliage and flowers close-up Photo by: P.R. Corpuz Biology Three of the speedwell species common in the Pacific Northwest are very similar in appearance. Ivyleaf speedwell (Veronica hederifolia), Persian […]

Speedwell foliage and flowers close-up.

Weeds: Spurges (Prostrate spurges) – Chamaesyce spp. (Euphorbia spp.)

Weeds: Spurges (Prostrate spurges) – Chamaesyce spp. (Euphorbia spp.) Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 03:20 Scientific name: Chamaesyce spp. (Euphorbia spp.) Family: Euphorbiaceae Cycle: Annual Plant type: Broadleaf Prostrate spurge with flowers Photo by: D.G. Swan Biology There are four prostrate weedy spurges that are common in the western United States. All […]

Prostrate spurge with flowers.

Weeds: Stinging nettle – Urtica dioica

Weeds: Stinging nettle – Urtica dioica Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 09:17 Scientific name: Urtica dioica Family: Urticaceae Cycle: Perennial Plant type: Broadleaf Stinging nettle flowers Photo by: R. Parker Biology Stinging nettles are typically erect, slender plants reaching two to nine feet high. The opposite leaves are coarsely toothed and often […]

Stinging nettle flowers.

Weeds: St. Johnswort, common (Goatweed, Klamathweed) – Hypericum perforatum

Weeds: St. Johnswort, common (Goatweed, Klamathweed) – Hypericum perforatum Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 04:36 Scientific name: Hypericum perforatum Family: Clusiaceae (Guttiferae) Cycle: Perennial Plant type: Broadleaf St. Johnswort in bloom Photo by: D.G. Swan Biology Common St. Johnswort is an erect shrubby plant one to three feet high arising from a […]

St. Johnswort in bloom.

Weeds: Tansy ragwort – Senecio jacobaea

Weeds: Tansy ragwort – Senecio jacobaea Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 07:53 Scientific name: Senecio jacobaea Family: Asteraceae (Compositae) Cycle: Biennial Plant type: Broadleaf Tansy ragwort Photo by: T.W. Miller Biology Tansy ragwort is a biennial or short-lived perennial spreading by seeds. In lawns, regular mowing may maintain it in a non-flowering […]

Tansy ragwort.

Weeds: Tumblemustard (Jim Hill mustard) – Sisymbrium altissimum

Weeds: Tumblemustard (Jim Hill mustard) – Sisymbrium altissimum Categories: Broadleaf Sh-Z Weeds Last review date: 2026-06-07 08:00 Scientific name: Sisymbrium altissimum Family: Brassicaceae (Cruciferae) Cycle: Annual Plant type: Broadleaf Tumblemustard in bloom image 1 Photo by: J.A. Kropf Biology Tumblemustard grows 2-5 feet tall. Seedling plants are low-growing rosettes of deeply lobed leaves. Mature plants […]

Tumblemustard in bloom image 1.

Weeds: Velvetgrass (Common velvetgrass) – Holcus lanatus

Weeds: Velvetgrass (Common velvetgrass) – Holcus lanatus Categories: Grasses Sh-Z Weeds Last review date: 2026-06-07 10:18 Scientific name: Holcus lanatus Family: Poaceae (Graminae) Cycle: Perennial Plant type: Grass Velvetgrass flowering Photo by: T.W. Miller Biology Velvetgrass is a perennial reaching one to three feet high (if unmowed). Typically growing in small, dense clumps, velvetgrass may […]

Velvetgrass with flowers and seedheads.