Names link to more information on identification and biology.
Click on photos to enlarge
Barnyardgrass
(Echinochloa crus-galli): Grass family; summer annual;
first leaf dull gray green; stem flattened, purplish; no
ligule. |
Black nightshade
(Solanum nigrum): Nightshade family; summer annual; seed leaves oval and pointed; first true leaves
spade shaped with smooth edges; lower surfaces often purple; petioles stems and leaves with some hairs. |
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 purslane
(Portulaca oleracea): Purslane family; summer annual;
seed leaves oblong, somewhat club shaped, succulent, maroon
on lower surface, and green or maroon on upper surface;
young leaves smooth, succulent, oblong, green on upper surface,
maroonish underneath, and broadest around leaf tip, with
short petioles. |
Hairy fleabane
(Conyza bonariensis): Sunflower family; summer annual;
seed leaves gray-green; first leaves narrow and covered
with short, soft hairs; often wrinkled or distorted.
Note:
may be confused with horseweed as both
plants grow in the same areas, but hairy fleabane
has a more branching growth habit with more abundant,
basal foliage. |
Horseweed
(Conyza canadensis): Sunflower family; summer annual;
seed leaves dull green, oval with fine hairs, their short
stalks sometimes tinged with dull brown purple; first true
leaves covered with hairs on upper surface and margins;
undersides of early leaves smooth.
Note: may be confused
with hairy fleabane as both
plants grow in the same areas, but
hairy fleabane has a more branching growth habit with more
abundant, basal foliage. |
Large crabgrass
(Digitaria sanguinalis): Grass family; summer annual; first leaf blade linear to lance shaped,
with stiff, jagged, and papery ligule; hairs on margins of the collar wide; no auricles; leaves covered
with coarse hairs; leaves rolled in bud. |
Morningglories
(Ipomoea spp.): Morningglory family; summer annual; seed leaves deeply notched; heart-shaped first
true leaves with deep lobes at base; stem below seed leaves maroon at base and green toward leaf tip. |
Prostrate pigweed
(Amaranthus blitoides): Pigweed family; summer annual;
seed leaves are narrow, pointed and 6 to 8 times longer than
broad; undersides are magenta; first true leaves are broader,
with shiny upper surface and usually magenta-tinged undersides;
edges somewhat rough. |
Puncturevine
(Tribulus terrestris): Caltrop family; summer annual;
seed leaves thick, brittle, 2 to 3 times longer than wide;
petioles pinkish; true leaves dark green with grayish underside
and rough margins. |
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.
|
Spotted spurge
(Chamaesyce maculata): Spurge family; summer annual; seed leaves oval, tips roundish, blue-green
with smooth margin; first true leaves rounded, leaf surface smooth and dull, dark green with reddish tinge. |
Bearded sprangletop
(Leptochloa fasicularis): Grass family; summer annual;
first leaves light green, usually with white midrib; blades
somewhat rolled; sheaths loose near base of plant; ligule
long, thin, membranous and tears easily. |
Tall annual willowherb
(Epibolium brachycarpum): Primrose family; summer annual; seed leaves small, round, often dark
reddish green; true leaves narrow, 4 to 5 times longer than wide, first true leaves opposite and smooth
around edges. |
Yellow foxtail
(Setaria pumila): Grass family; summer annual; first
blade linear, roughly 7 times longer than wide and opens almost
parallel to ground; leaves rolled in bud; ligule—fringe
of hairs; no auricles; no hairs on leaf-sheath margin below
collar; leaf blades of young seedlings smooth on lower surface,
with long hairs on basal area of upper surface; margins smooth
or slightly rough. |
