Weed Science Flashcards
Giant Hogweed
Heracleum mantegazzianum
Apiaceae
Perennial
Redroot Pigweed
Amaranthus retroflexus
Amaranthaceae
Annual
Hardhack
Spiraea tormentosa
Rosaceae
Perennial
Lamb’s Quarters
Chenopodium album
Chenopodiaceae
Annual
Yellow Toadflax
Linaria Vulgaris
Scrophlariaceae
Perennial
Purple Loosestrife
Lythrum salicaria
Lythraceae
Perennial
Square stem
Bracken Fern
Pteridium aquilinum
Dennstaedtiaceae
Perennial
Field Horsetail
Equisetum arvense
Equisetaceae
Perennial
Corn Spurry
Spergula arvensis
Caryophyllaceae
Summer or Winter Annual
Hedge Bindweed
Calystegia sepum
Convolvulaceae
Perennial
Mouse-eared chickweed
Cerastium vulgatum
Caryophyllaceae
Perennial
Slightly furry leaves
Black Nightshade
Solanum nigrum
Solanceae
Perennial
Japanese Knotweed
Fallopia japonica
Polygonaceae
Perennial
Yellow Flag Iris
Iris pseudocorus
Iridaceae
Perennial
Prostrate Knotweed
Polygonum aviculare
Polygonaceae
Annual
Broadleaf dock
Rumex obtusifolius
Polygonaceae
Perennial
Sheep Sorrel
Rumex acetosella
Polygonaceae
Annual OR Perennial
Wild Buckwheat
Polygonum Convolvulus
Polygonaceae
Annual
Sandpapery texture
Stinkweed
Thlaspi arvense
Brassicaceae
Annual
Stork’s Bill
Erodium circutarium
Geraniaceae
Annual
Hedge Mustard
Sisymbrium officiniale
Brassicaceae
Annual
Shepherd’s Purse
Capsella bursa-pastoris
Brassicaceae
Annual
Hoary Alyssum
Berteroa incana
Brassicaceae
Annual or Perennial
Little bittercress
Cardamine oligosperma
Brassicaceae
Annual or Biennial
Wild Radish
Raphanus raphanistrum
Brassicaceae
Annual
Creeping Yellow Cress
Rorippa sylvestris
Brassicaceae
Perennial
Slightly ragged or pinnate look
Common mullein
Verbascum thapsus
Scropulariaceae
Biennial
Lady’s thumb
Polygonum persicaria Polygonaceae Annual OR Persicaria maculosa Hairy ligules
Foxtail barley
Hordeum jubatum
Poaceae
Perennial
St. John’s Wort
Hypericum perforatum
Hypericaceae
Perennial
Slight perforations around margin of leaf
Petty Spurge
Euphorbia peplus
Euphorbiaceae
Annual
Stinging nettle
Urtica dioica
Urticaceae
Perennial
Common mallow
Malva neglecta
Malvaceae
Annual to short perennial
Fireweed
Epilobium angustifolium
Onagraceae
Perennial
OR Chamerion angustifolium
Purslane
Portulaca oleracea
Portulacaceae
Annual
Green foxtail
Setaria viridis
Poaceae
Annual
Barnyard Grass
Echinochloa crusgali
Poaceae
Annual
No fur!
Annual bluegrass
Poa annua
Poaceae
Annual
Green Smartweed
Polygonum scabrum or lapathifolium Polygonaceae Annual OR Persicaria lapathifolium No hair on ligules
Large crabgrass
Digitaria sangulinalis
Poaceae
Annual
Quackgrass
Agropyron repensi
Poaceae
Perennial
Only hairy on upper leaf, presence of auricles
Witchgrass
Panicum capillare
Poaceae
Annual
Has hair!
Smooth crabgrass
Digitaria ischaemum
Poaceae
Annual
Himalayan Blackberry
Rubus armeniacus
Roasaceae
Perennial
Downy Brome
Bromus tectorum
Poaceae
Annual
Very hairy leaves, twisting leaves
Distinguish Lady’s Thumb and Green Smartweed (Give scientific names)
Lady’s Thumb (Polygonum persicaria) has hairy ligules and is often spotted with pink flowers while Green Smartweed (Polygonum scabrum) has smooth ligules, no spots, and white flowers.
Distinguish Common Chickweed and Mouse-eared Chickweed.
Common Chickweed (Stellaria media) is an annual with relatively smooth leaves whereas Mouse-eared Chickweed is a perennial with fuzzy leaves.
Distinguish Hedge Bindweed and Wild Buckwheat
Hedge Bindweed (Calystegia sepium) is a perennial with large white flowers (fused corolla) whereas Wild Buckwheat is an annual with smaller flowers and a sandpapery texture to the leaves.
Distinguish Creeping Yellow Cress and Little Bittercress
Little bittercress (Cardamine oligosperma) is an annual and has smoother, kidney-shaped leaves arranged alternately as pinna whereas Creeping Yellow Cress (Rorippa sylvestris) is a perennial with slightly more ragged margins and the leaves are fused to the stipe.
Distinguish Witchgrass and Barnyard Grass
Witchgrass (Panicum capillare) is hairy along the stem and the inflorescence resembles a broom. Barnyard grass is smooth.
Reed Canary Grass
Phalaris arundinaceae
Poaceae
Perennial
45 degree angle leaves
Distinguish Downy Brome and Quackgrass
Downy Brome (Bromus tectorum) is an annual with no auricles but a large jagged ligule and is slightly fuzzy with twisting leaves. Quackgrass is a perennial with auricles and only has a slight bit of hair on the upper surface.
Name and differentiate Green Foxtail and Barnyard Grass.
Green Foxtail (Setaria viridis) is an annual with an upright growth pattern and bristled inflorescence, whereas Barnyard Grass (Echinochloa crus-galli) is an annual with a low growth pattern and smooth inflorescence.
Compare and differentiate Redroot Pigweed and Broadleaf Dock
Redroot Pigweed is an annual with reddish stems near the roots, sparsely hairy leaves, and numerous green spikes (inflorescence). Broadleaf dock is a perennial with green stems, smooth, yet wrinkly leaves (mostly basal).
Distinguish Shepherd’s Purse, Stinkweed, and Wild radish.
Shepherd’s Purse has heart-shaped fruits and rosette leaves are lobed (shallow or deep) whereas stem leaves are sessile. Stinkweed has lilypad shaped seed pods and whole, stalked,
rosette leaves with slightly wavy margins.
Wild Radish has deeply divided rosette leaves, leguminous seed pods.
Distinguish Corn Spurry and Field Horsetail
Corn Spurry is an annual with small white flowers whereas Field Horsetail is a perennial that bears cones. Horsetail has hollow stems and underground rhizomes as well as 6-8 branches per whorl whereas Spurry is branching from the base and has 6-30 leaves per whorl
Perennial sow-thistle
Sonchus arvensis
Asteraceae
Perennial
Spiny annual sow-thistle
Sonchus oleraceus
Asteraceae
Annual
Spotted cat’s ear
Hypochaeris radicata
Asteraceae
Perennial
Tansy
Tanacetum vulgare
Asteraceae
Perennial
Creeping buttercup
Ranunculus repens
Ranunculaceae
Perennial
Narrow-leaved plantain
Plantago lanceolata
Plantaginaceae
Perennial
Broad-leaved plantain
Plantago major
Plantaginaceae
Perennial
Red Clover
Trifolium pratense
Fabaceae
Perennial
Scotch broom
Cytisus scoparius
Fabaceae
Perennial
Dandelion
Taraxacum officiniale
Asteraceae
Annual
Canada Goldenrod
Solidago canadensis
Asteraceae
Perennial
Common burdock
Articum minus
Asteraceae
Biennial
Bull thistle
Cirsium vulgare
Asteraceae
Biennial
Yarrow
Achillea millefolium
Asteraceae
Perennial
Diffuse knapweed
Centaurea diffusa
Asteraceae
Biennial
Canada fleabane
Conyza canadensis
Asteraceae
Annual or Winter Annual
Canada thistle
Cirsium arvense
Asteraceae
Perennial
Kudzu
Pueraria montana var. lobata
Fabaceae
Perennial
Flowering Rush
Butomus umbellatus
Butomaceae
Perennial
Yellow Archangel
Lamiastrum galeobdolan
Lamiaceae
Perennial
Yellow Starthistle
Centaurea solstitialis
Asteraceae
Winter Annual
Hound’s Tongue
Cynoglossum officinale
Boraginaceae
Biennial
English Ivy
Hedera helix
Araliaceae
Perennial
English Holly
Ilex aquifolium
Aquifoliaceae
Perennial
Tansy Ragwort
Senecio jacobaea
Asteraceae
Biennial to short-lived perennial
Henbit
Lamium amplexicaule
Lamiaceae
Annual
Daphne Laurel
Daphne laureola
Thymelaeaceae
Perennial
White Clover
Trifolium repens
Fabaceae
Perennial?
Black medick
Medicago lupulina
Fabaceae
Annual
Tufted Vetch
Vicia cracca
Fabaceae
Perennial