invasive

Showing 13–24 of 42 results

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
Equisetum hyemale / rough horsetail
- thin green stems with black bands; no branches
- possible cone-like structure at the apex
- usually in large colonies
- prefers continuously moist soils
Fragaria vesca / woodland strawberry
- trifoliate, light green markedly toothed leaves
- clusters of hairy, 5-petaled white flowers on a soft-hairy stem
- plants spread by stolons
- fruit (if any) red with bumps where the seeds are
- spring/early summer bloom
- widespread
Grindelia squarrosa / Curly cup gumweed
- small-ish yellow flowers
- button-like buds
- attractively compact, globe-shaped plant
Helianthus annuus / sunflower
- tall with big, drooping leaves (up to 15x15 inches)
- large sunflower like flowers - yellow petals, darker disk
- disturbed edges and waste areas, roadsides, near crops
Hieracium aurantiaca / orange hawkweed
- orange dandelion-like flower
- petals square ended with small notches
- hairy leaves, stems and involucres
- found in many habitats, sometimes in excess
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.
Hypericum perforatum / St. John’s wort
- bright yellow, 5-petaled flowers
- many stamens sticking out every which way
- sizable black and/or white glands on leaves and petals
- waist high and grows in large colonies (invasive)
- not (yet) seen west of the Tetons
Lactuca serriola / prickly lettuce
- numerous dime-sized yellow flowers in an "airy" panicle
- buds droop or hang in a "shepherd's hook" before opening
- seed heads are dandelion-like, but more delicate
- highly divided, prickly leaves
- mostly in "waste" areas
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
Lotus corniculatus / birds-foot trefoil
- roadsides and other disturbed areas
- numerous bright yellow, pea-like flowers
- three, oval and pointed leaflets
- seed pods are arranged like toes on a bird's foot