1. Poison Hemlock

    Conium maculatum Poison Hemlock - Very tall biennial that can grow up to around 12 feet in height. Stems will have purple splotches that help with identification.Leaves: Leaves are fern-like, toothed and finely divided. Look very similar to wild carrot leaves.Flowers: Flowers bloom from April-August. Flowers are small, white, and occur in 4–8-inch umbrella-shaped clusters.Habitat: Plant is highly adaptive, but prefers rich, moist soil.Weed Classification: B SelectWhy is it a Noxious Weed?The entire plant is toxic to animals and humans. Contains poisonous alkaloids, such as coniine. Poison Hemlock can spread quickly and infest large areas.Poison Hemlock should not be burned, …


    Weed Control - Sept. 29, 2022, 9:48 a.m.

  2. Eggleaf Spurge

    Euphorbia oblongata Eggleaf Spurge - Upright perennial growing about 3 feet tall. Has a woody, branched taproot. Plant stems covered in fine white hairs.Leaves: Alternate and hairless leaves that are oblong and finely toothed. Prominent midvein is visible.Flowers: Flowers bloom from May-July. Clustered flowers with a few male flowers and one female flower. Clusters have yellow bracts (scales) at their base followed by a whorl of yellowish green leaves.Habitat: Typically found in damp meadows, streambanks, shadow woodlands, dry hillsides, roadsides, and waste areas.Weed Classification: AWhy is it a Noxious Weed?Originally introduced as a garden ornamental. This plant is invasive and …


    Weed Control - Sept. 29, 2022, 10:46 a.m.

  3. Oriental Clematis

    Clematis orientalis Oriental Clematis - A moderately vigorous, climbing shrub that forms a mass of stems and grows upwards of 27 feet long.Leaves: Opposite on stems, pinnately compound with 5-7 leaflets.Flowers: Flowers bloom from June-December. Can be single flowers or flower clusters. Generally, they have 4 yellow/green sepals that look like petals.Habitat: Found in gullies, riverbanks, streambanks, roadsides, open woods, steep hillsides, and irrigation canals.Weed Classification: AWhy is it a Noxious Weed?Can establish in a variety of habitats and forms dense infestations which can kill small plants and trees. Can be extremely difficult to control, once established.Clematis can be found …


    Weed Control - Sept. 29, 2022, 10:57 a.m.

  4. Buffalobur

    Solanum rostratum Buffalobur - An annual plant growing around 1.5-3 feet tall, covered in spines and hairs.Leaves: Alternate leaves 2-6 inches long. Leaves are irregularly cut into 5-7 lobes and are very prickly.Flowers: Flowers bloom from June-September. 3-15 flowers per flower cluster. Flowers are bright yellow, 5 lobed, flat, and circular shaped about an inch across.Habitat: Found in fields, overgrazed pastures, yards, road sides, waste areas, barn yards, it can grow in sandy soil, dry soil, and rich moist soil.Weed Classification: CWhy is it a Noxious Weed?Buffalobur is toxic to livestock, and spreads easily in pastures and fields outcompeting desired …


    Weed Control - Oct. 6, 2022, 9:32 a.m.

  5. Canada Thistle

    Cirsium arvense Canada Thistle - A rhizomatous, perennial, herbaceous plant that grows 2-5 feet tall, usually branching only near the top of the plant.Leaves: Leaves are alternate and lance to narrowly oval in shape, possessing short spines along the leaf edges.Flowers: Flowers bloom from May-October. Many flowerheads clustered towards the tip of the stem, purple to pink in color.Habitat: Common in pastures and croplands. Can also invade wet areas as well like steam banks, sedge meadows, and wet prairies.Weed Classification: C SelectWhy is it a Noxious Weed?Once established, it can spread vigorously and replaces native plants. It also lowers crop …


    Weed Control - Oct. 6, 2022, 9:32 a.m.

  6. Oxeye Daisy

    Leucanthemum vulgare Oxeye Daisy - A perennial, herbaceous plant growing 1-3 feet tall.Leaves: Leaves are alternate and lance-shaped, with toothed or lobed edges.Flowers: Flowers bloom from May-October. Single flowerhead at the end of the stem. It has many white ray-flowers, creating the "petals," and yellow disc-flowers in the middle.Habitat: Found in grasslands, overgrazed pastures, waste areas, meadows, roadsides, railroad ROWs, yards, and fields.Weed Classification: CWhy is it a Noxious Weed?It can aggressively invade fields and decrease plant diversity. It decreases crop yield and has rhizomes with adventitious roots.Oxeye Daisy is very common in Lewis County. It can be hard to …


    Weed Control - Oct. 6, 2022, 9:32 a.m.

  7. Yellow Toadflax

    Linaria vulgaris Yellow Toadflax - A perennial growing 8-31 inches tall from creeping roots. Forms colonies.Leaves: Many narrow, linear leaves up to 4 inches in length, alternating along the stem.Flowers: Flowers bloom from June-September. Many flowers crowd the top 2-9 inches of the plant. Flowers are yellow, hairy, and have orange "throats." Resembles snapdragons.Habitat: Grows in a variety of habitats, including: roadsides, edges of fields, rangelands, meadows, cultivated fields, and waste areas.Weed Classification: CWhy is it a Noxious Weed?It can easily invade range and farmlands outcompeting desirable crops/forage. Livestock will rarely eat the plant.Yellow Toadflax can infest cultivated land easily, …


    Weed Control - Oct. 6, 2022, 9:33 a.m.

  8. Himalayan Knotweed

    Persicaria wallichii Himalayan Knotweed - A clumping perennial with hollow stems and creeping rhizomes. It grows about 6 feet in height.Leaves: Leaf shape is elongated compared to other knotweeds and are around 5-12 inches in length. They are leathery and alternate along the stem.Flowers: Flowers bloom from July-October. Whiteish pink flowers that are fragrant grow at the tips of branches.Habitat: Grows in disturbed, moist sites like roadsides, riparian, and wetland areas.Weed Classification: B DesignateWhy is it a Noxious Weed?This plant vigorously grows into dense stands that overtake native vegetation and alter ecosystems. It can survive severe floods and spread plant …


    Weed Control - Oct. 5, 2022, 4:16 p.m.

  9. Curlyleaf Pondweed

    Potamogeton crispus Curlyleaf pondweed - The entire plant stays underwater, except for the flower stalk, and usually only grows in the spring before dying off in the late summer.Leaves: Leaves are alternate along the stem, submerged, and oblong in shape. They are also stiff with distinctly wavy edges and fine teeth.Flowers: Flowers bloom from June-August. Flowers are very small and have 4 petal-like lobes.Habitat: Grows in shallow or deep water that can either be still or flowing and tolerates disturbances.Weed Classification: C SelectWhy is it a Noxious Weed?This plant can form dense colonies on the surface that interfere with aquatic …


    Weed Control - Oct. 5, 2022, 4:38 p.m.

  10. Knapweeds (Spotted, Diffuse, and Meadow)

    Centaurea spp. (stoebe, diffusa, and x moncktonii) Spotted Knapweed Rosette Spotted Knapweed Diffuse Knapweed Rosette Diffuse Knapweed Meadow Knapweed Meadow Knapweed rosette Spotted Knapweed - A biennial or perennial that typically grows about 5 feet tall and has a stout taproot. Is hairy with a rough and woolly appearance. First year rosettes and second year flowering stems.Leaves: Rosette leaves deeply lobed, upper leaves are generally un-lobed.Flowers: Flowers bloom from June-October. Solitary flowerheads. Egg-shaped plant scales (bracts) with a black/brown triangular tip that make the plant look spotted.Diffuse Knapweed - An annual, biennial, or perennial plant growing up to around 3 …


    Weed Control - Sept. 29, 2022, 9:48 a.m.