1. Common Tansy

    Tanacetum vulgare Common Tansy- This pungent perennial grows up to 5' tall and spreads via wind-dispersed seeds, as well as by rhizomes.Leaves: Alternate and pinnately compound, they are deeply divided into toothed segments and become smaller towards the top of the stalk.Flowers: Flowers bloom from July to October. Numerous clusters of button-like yellow flowers that have a flat top and are 1/4 to 1/2 inches wide.Habitat: It is extremely common to find along roadsides, waste areas, stream banks and in pastures.Weed Classification: BWhy is it a Noxious Weed? Because of its aggressive nature and risk of toxicity to livestock. Like …


    Weed Control - Sept. 29, 2022, 9:46 a.m.

  2. Lewis County Noxious Weed Map

    ArcGIS Noxious Weeds Map Click on the map icon to the left to view. In 2022, your noxious weed control team began recording noxious weed infestations on iForm to be displayed on this map. Although many infestations noted this year have not yet been uploaded, in addition to missing most historical records, we believe this is a great start to a more manageable and efficient tracking system.


    Weed Control - Dec. 11, 2023, 10:27 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. Field Bindweed

    Convolvulus arvensis Field Bindweed - An herbaceous perennial with extensive rhizomes that help it creep through fields and over plants.Leaves: Arrowhead-shaped leaves that alternate along the stem. Leaves have two lobes at the base.Flowers: Flowers bloom from April-October. Flowers are bell or funnel-shaped and are about 1 inch across. They range from white-pink and have bracts (scales) where the flower stem meets the plant stem.Habitat: It grows anywhere from full sun to full shade and is drought tolerant. Found in ravines, greenbelts, forested parks, farmlands, driveways, flower gardens, and ornamental bordersWeed Classification: CWhy is it a Noxious Weed?Once established it …


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

  5. Giant Hogweed

    Heracleum mantegazzianum Giant Hogweed - A perennial, or sometimes biennial, plant capable of growing 15-20 feet tall. Stout dark reddish-purple splotched stems and leaf stalks.Leaves: Leaves can grow up to 5 feet wide, and they are deeply cut/lobed and sharply toothed edges.Flowers: Flowers bloom from June-August. Flower clusters can grow 2.5 feet wide and are umbrella shaped with many small white flowers.Habitat: Can grow in a variety of habitats, but primarily found along roadsides, rights-of-way, vacant lots, streams, and rivers.Weed Classification: AWhy is it a Noxious Weed?Due to the plant's height, it forms dense canopies that outcompete native species. Plants …


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

  6. Gorse

    Ulex europaeus Gorse - A thorny perennial shrub that closely resembles Scotch Broom and can grow to be 10+ feet tall.Leaves: Leaves are small, dark green and trifoliate — having 3 thin leaflets. As they mature, they become spiny. The leaf axils also have spines.Flowers: Flowers bloom April - September. Bright yellow pea-like flowers form clusters near branch terminals.Habitat: Can grow in most habitats, but is especially prevalent in coastal environments.Weed Classification: B DesignateWhy is it a Noxious Weed? Aside from "noxious" growth habits, gorse also creates large physical barriers and poses significant wildfire risk due to the concentration of …


    Weed Control - Sept. 29, 2022, 9:47 a.m.

  7. European Coltsfoot

    Tussilago farfara European Coltsfoot - a rhizomatous perennial that forms intricate colonies and grows up to 18" tall.Flower: Flowers bloom from March - May. The solid yellow flower looks somewhat like a dandelion, but on a stem absent of any basal leaves. The stems are unbranched and each produces a single flower.Leaves: Basal leaves emerge after flowers begin going to seed. They vary in size from 2-12" and grow from the rhizomes in rosettes. They also have a big variation in size and can be heart shaped, orbicular, or triangular, and have a narrow indentation at the base. The margins …


    Weed Control - Sept. 29, 2022, 9:45 a.m.

  8. Hawkweeds

    Hieracium spp. Orange Hawkweed Mouseear Hawkweed Hawkweeds - Most hawkweed species are hairy and have a milky latex in their stems.Leaves: Most species will have basal leaves. Stem leaves can vary by subgenus. Leaves can be smooth, toothed, or lobed.Flowers: Blooms typically May - Sep. Most non-native species will have yellow ray flowers, but some species can have orange flowers as well. Flowers looks similar to dandelion flowers.Habitat: Typically found in fields, meadows, pastures, forest clearings, and disturbed areas like roadsides and abandoned farmland.Weed Classification: B DesignateWhy is it a Noxious Weed?The plants are invasive, spread easily, and negatively impact …


    Weed Control - Sept. 29, 2022, 9:47 a.m.

  9. Scotch Broom

    Cytisus scoparius Scotch Broom - Everyone's favorite noxious weed! A woody perennial shrub that has many branches. Plants can range from 3-10 feet tall.Leaves: Scotch Broom has few leaves. The upper leaves are simple with the lower leaves being 3 parted. Leaves are pointed at each end and can fall early in the year, leaving bare, green stems.Flowers: Flowers bloom from March through June. Typical pea family flowers in shape. Bright yellow in color with 5 petals.Habitat: Typically, can be found along roadsides, in pastures, grasslands, and open areas with recent soil disturbance.Weed Classification: B SelectWhy is it a Noxious …


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

  10. 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.