The weeds shown here may be seen in
fall-planted alfalfa seedlings. For weeds in spring-planted alfalfa
seedlings, see common
summer weeds. Names link to more information
on identification and biology.
Click on photos to enlarge
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.
|
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. |
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. |
Common groundsel
(Senecio vulgaris): Sunflower family; winter annual; seed leaves narrow,
with blunt narrow tip; first true leaves with shallow teeth; third and fourth
leaves more deeply lobed. |
Common knotweed
(Polygonum arenastrum): Seed leaves are long, very narrow, rounded at
the tip and light green with a white cast. The true leaves are much broader,
emerging from an encircling, membranous sheath at the leaf base. |
Fiddlenecks
(Amsinckia spp.): Borage family; winter annual; Y-shaped seed leaves with
tiny blisters and a few fine hairs; early leaves with coarse, sharp hairs, and
4 to 6 times longer than wide. |
London rocket
(Sisymbrium irio): Mustard family; winter annual; seedlings narrow with
long stalks; margins of first true leaves indented, distinguishing seedlings
of London rocket from those of shepherd's purse; seedlings with deeply lobed
leaves.
|
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.
|
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.
|
Shepherd’s-purse
(Capsella bursa-pastoris): Mustard family; winter annual; seed leaves
pale green with tiny granules on surface; first true leaves with smooth margins;
fourth and later leaves may be indented; true leaves covered with star-shaped
hairs.
|
Wild oats
(Avena fatua): Grass family; winter annual; first leaves with small marginal
hairs and counterclockwise twist when viewed from above; ligule large, papery,
and pointed.
|
Yellow starthistle
(Centaurea solstitialis): Aster family; winter annual; seedlings are dull
green; seed leaves are oblong, round at the tip, with smooth edges; first true
leaves are longer and narrower with short, white hairs on the upper surface. |
