invasive

Showing 1–12 of 39 results

  • Alyssum desertorum / desert madwort

    • short crucifer with teeny leaves, no basal rosettes
    • short inflorescence with numerous teeny yellow flowers... short-lived
    • seed capsules mature by mid-July, ca. 40/stalk
    • disturbed sites of any kind
    • often in dense populations

  • Amaranthus retroflexus / pigweed

    • green bottle-brush inflorescence
    • accomplished weed on disturbed sites (including road & driveway cracks)
    • often in gardens, farm fields (edges), roadsides

  • Arctium minus / lesser burdock

    • purple to pink to lavender thistle-like flowers with hooked bracts
    • nasty hooked seed heads
    • very large, heart-shaped leaves
    • found in a wide variety of disturbed areas

  • Barbarea vulgaris / yellow rocket

    • showy yellow brassica with relatively large flowers
    • leaves deeply lobed with larger terminal lobe, smaller toward top of stems
    • common on roadsides and waste places in spring
    • siliques about an inch long and curving upward, with beaks and pedicels

  • 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 inermis / smooth brome

    • clump forming grass but clonally spreading
    • erect, leafy
    • in winter, leaves curl up (like ribbon)
    • florescence is a nodding panicle, standing well above leaves
    • spikelets bronze/purple at maturity; anthers yellow

  • 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!

  • 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

  • Cicuta douglasii / water hemlock

    • HIGHLY TOXIC
    • primarily on continuously wet soils, e.g. ditches, stream banks, pond margins, marshes.
    • white compound umbel inflorescence typical of the Apiaceae/Umbelliferae
    • multiply compound leaves with prominent veins ending in notches between lobes

  • 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

Showing 1–12 of 39 results