noxious

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  • Bassia scoparia / burningbush

    • large, annual herb (forb)
    • leaves long-ish and narrow
    • inflorescence a highly branched spike with teeny green/yellow flowers
    • may form huge, invasive colonies
    • whole plant turns red in fall
    • a tumbleweed
    • especially in disturbed areas and wastelands in the Valley
  • Beteroa incana / hoary alyssum

    • dense clusters of teeny white flowers
    • 4 petals, each with a notch
    • fruit is a short, fat-ish seed pod (silicle)
    • found in pastures and all manner of disturbed habitats
    • toxic to horses
  • Bromus tectorum / cheatgrass

    • short bunchgrass, 2 to 30 in at floweirng
    • panicle with all florets to one side; long awns
    • early season growth, flowering, seed drop
    • florets green, turning purple as seeds mature
    • highly invasive!
  • Carduus nutans / musk thistle

    • quite large, very purple flower heads
    • spiny everything... leaves, stems, bracts
    • biennial - large rosette of nasty leaves in first year
    • dandelion-like fruit that flies away like the down of a thistle
    • disturbed lands... pastures, wastelands, roadsides, construction sites
  • Centaurea maculosa / spotted knapweed

    • "vibrant" pink flowers
    • dark tips on the sepals ("bud scales") - the "spotted" in the name
    • biennial - rosette of leaves in first year
    • officially a noxious weed
  • Cirsium arvense / Canada thistle

    • purple or lavender clearly-thistle flower heads
    • multiple small flower heads per stem
    • deeply lobed, spiny leaves, but stems not spiny
    • clonal and perennial
    • in clumps or along roads, sometimes quite large/long
  • Convulvulus arvensis / field bindweed

    • prostrate and twining vine with white "morning-glory" flowers
    • may be so dense as to choke out other plants
    • roadsides, agricultural fields, waste areas
    • "noxious" in Idaho
  • Cynoglossum officinale / houndstongue

    • reddish-purple flowers in upper leaf axils
    • forms basal rosette with hairy leaves in first year
    • stem leaves lance shaped, hairy, rough
    • fruit - small nutlets with barbs or hooks
  • Hyocyamus niger / black henbane

    • highly toxic! including contact dermatitis
    • 5-lobed, funnel-shaped flowers, brownish yellow with purple veins and center; 1.5" across
    • flowers in summer, e.g. warm June, July
    • elliptical leaves, pointy tips, toothed or lobed margins, prominent veins
    • highly disturbed areas: wastelands, field edges etc.
  • Leucanthemum vulgare / oxeye daisy

    • bright, white "petals", 2-3" across; yellow centers
    • s/he loves me, s/he loves me not
    • glossy green, spoon-shaped leaves in a 2 foot dome
    • may form large colonies
    • potentially wide spread
  • Linaria vulgaris / yellow toadflax

    • fine, threadlike leaves, plants up to 3 feet tall
    • flowers similar to snapdragon, pale yellow with orange lower lip, long spur
    • flowers in tight terminal clusters
    • plants typically in patches
    • "noxious" weed in Idaho
  • Sonchus arvensis / field sowthistle

    • yellow dandelion-like
    • multiple flowers per stalk
    • often in patches in wet fields
    • leaves spiney but without lobes, clasping the stems
    • often several stems from a single point at the soil level

Showing all 12 results