Use the photos below to identify weeds
in the field. Names link to information on
identification and biology.
Click on photos to enlarge
Purple cudweed
(Gnaphalium purpureum): Sunflower family; winter annual, summer annual,
or biennial; seed leaves and first true leaves covered on both sides with whitish
hairs; seed leaves 2 to 3 times longer than wide. |
Common groundsel
(Senecio vulgaris): Sunflower family; winter annual, but seedlings can
be present anytime at cool, moist locations; seed leaves narrow, with blunt narrow
tip; first true leaves with shallow teeth; third and fourth leaves more deeply
lobed. |
Milkthistle (Silybum
marianum): Sunflower family; winter or summer annual
or biennial; seed leaves broadly oval, thick, smooth; first
true leaves alternate, oblong, margins with prickly teeth,
upper surfaces with white markings. |
Prickly lettuce
(Lactuca serriola): Sunflower family; winter annual or biennial; seed
leaves about 2 times longer than wide; first true leaves with rounded margins;
injured tissue bleeds milky white latex. |
London rocket
(Sisymbrium irio): Mustard family; winter annual; seedlings narrow with
long stalks; first true leaf oval, margins smooth or with a few weak teeth; subsequent
few leaves similar but with shallow-toothed margins; young plants have deeply
lobed leaves. |
Mustards
(Brassica spp.): Mustard family; winter annual; all mustard seedlings
with broad seed leaves and deep notch at tip; first true leaves bright green
on the upper surface and paler below. |
Little mallow (Cheeseweed)
(Malva parviflora): Mallow family; winter annual; seed leaves heart shaped,
sometimes with red tinge; true leaves roundish with wavy, shallow-toothed margins. |
Burning nettle
(Urtica urens): Nettle family; winter or summer annual; rounded seed leaves
with smooth margin and small notch at tip; first true leaves with small notch
at tip, opposite, stalked, and distinctly toothed. |
Common chickweed
(Stellaria media): Pink family; winter annual; seed leaves with prominent
midveins, about 4 times longer than wide, tapering to point at tip; true leaves
broader, opposite, and yellow-green. |
Redstem filaree
(Erodium cicutarium): Geranium family; winter annual; seed leaves deeply
3- to 4-lobed, center lobe largest; first true leaf deeply lobed and covered
with white hairs; young leaves alternate or opposite and also deeply lobed. |
Hare barley
(Hordeum murinum ssp. leporinum): Grass family; winter
annual; papery ligule with long and narrow clasping auricles; hairy foliage. |
Annual bluegrass
(Poa annua): Grass family; winter annual; leaf tip shaped like bow of
a boat; membranous ligule rounded with slightly pointed tip; leaf blade crinkled
at midsection. |
Italian ryegrass
(Lolium multiflorum): Grass family; winter annual; first blade erect,
long, and narrow; leaves rolled in bud, blades with shiny, varnished appearance;
ligule membranous; usually auricles present, but sometimes absent on very young
seedlings. |
Wild oat
(Avena fatua): Grass family; winter annual; first leaves with small marginal
hairs and counterclockwise twist when viewed from above; ligule large, papery,
and pointed. |
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