WW-00776
Reviewed 1999
Characteristics of Common Broadleaf Weed Seedlings
Some common broadleaf weed seedlings with their identifying vegetative
characteristics follow:
Velvetleaf
| Cotyledons |
spread about 32 mm; short; ovate, with long petioles; prominent
and branched midvein; velvety-green |
| Leaves |
alternate; ovate, with serrated margins and long petioles; branched
midvein; leaves and petioles velvety-hairy |
| Hypocotyl |
velvety-hairy |
| Growth habit |
annual |
Cocklebur
| Cotyledons |
spread up to 80 mm; tend to be triple veined at base; long;
narrow; acute (tapering to a point) at tip; sessile (no petiole); rough
|
| Leaves |
opposite, becoming alternate; triple veined at base; veins
prominent; rough-hairy; short petioled |
| Hypocotyl |
rough; purplish |
| Growth habit |
annual |
Field bindweed
| Cotyledons |
spread about 40 mm; broadly heart shaped; venation distinct;
long petioled
|
| Leaves |
dark green; shiny; glabrous; the first leaves heart shaped, margin
indented at the petiole; later leaves sagittate (arrowhead shaped)
|
| Hypocotyl |
smooth; often purplish; stem twining
|
| Growth habit |
perennial
|
Canada thistle
| Cotyledons |
spread about 15 mm; oval; rough; distinctly veined
|
| Leaves |
ovate; sessile (no petiole), with sharp spines and prominent
midvein, becoming irregularly lobed
|
| Hypocotyl |
short; whitish-green; rough
|
| Growth habit |
perennial
|
Perennial sowthistle
| Cotyledons |
spread about 20 mm; short petioled; obovate (widest near tip);
smooth
|
| Leaves |
first leaves smooth, shiny green, ovate, narrowed at base into a
winged petiole; later leaves variously lobed or toothed; teeth reflexed
(bent backward); weak spined; milky juice
|
| Hypocotyl |
short; smooth; stem with milky juice
|
| Growth habit |
perennial
|
Wild mustard
| Cotyledons |
spread about 26 mm; wider than long, with shallow oval notch or
indentation at tip; long glabrous petioles; branched midvein
|
| Leaves |
alternate; oval to spatulate (spoon shaped) with undulate
(wavy-edged) or bluntly toothed margins; prominent and branched midvein;
trichomatous (with hairlike projections) on leaves and petioles
|
| Hypocotyl |
usually reddish in color
|
| Growth habit |
annual
|
Kochia
| Cotyledons |
spread about 11 mm; linear shape with no petioles (sessile);
sometimes faintly veined; gray or frosty-green on upper surface and red on
lower; circular swelling at growing point between cotyledons
|
| Leaves |
appear opposite but become alternate--pairs are so close together
they form a small rosette between cotyledons; linear shape with no
petioles; very hairy
|
| Hypocotyl |
reddish to purplish in color
|
| Growth habit |
annual
|
Russian thistle
| Cotyledons |
spread about 25 mm; extremely long, narrow shape, with no
petioles
|
| Leaves |
opposite, becoming alternate; extremely long, narrow, threadlike
shape, with no petioles; older leaves barb tipped
|
| Hypocotyl |
reddish in color
|
| Growth habit |
annual
|
Common lamb's-quarters
| Cotyledons |
spread about 13 mm; linear shape; red on lower surface, light
green on upper
|
| Leaves |
opposite, becoming alternate; oval to ovate; light green with
frosty or white mealy appearance; short petioles; mid-vein with little or
no evident branching
|
| Hypocotyl |
light red in color
|
| Growth habit |
annual
|
Redroot pigweed (Prostrate pigweed and Hybrid pigweed are very similar)
| Cotyledons |
spread about 14 mm; linear shape, with short petioles; lower
surface and midvein on upper surface reddish in color
|
| Leaves |
alternate; ovate to oval, with indented tips and medium-long,
sparsely trichomatous (with hairlike projections) petioles; branched
midvein
|
| Hypocotyl |
light red in color
|
| Growth habit |
annual
|
Wild buckwheat
| Cotyledons |
spread about 25 mm; linear shape, with short petioles;
prominent midvein on lower surface and sometimes on upper
|
| Leaves |
alternate; ovate, with long, pointed tip giving a heart shaped
appearance; long petioles; prominent and branched midvein; each bears an
ochrea (membranous sheath) at base of petiole; small trichomes (hairlike
projections) on stem and leaf petiole
|
| Hypocotyl |
short; reddish; often covered with short, bristle-like
projections
|
| Growth habit |
annual
|
Pennsylvania smartweed
| Cotyledons |
spread about 41 mm; linear on one edge, curved on the other;
reddish blotch on lower surface; sparsely trichomatous (with hairlike
projections) on margins
|
| Leaves |
alternate; long oval to spatulate (spoon shaped); prominent
midvein; each leaf bears an ochrea (membranous sheath) at base of leaf
petiole; sparsely trichomatous (with bristly hairs) on margins
|
| Hypocotyl |
reddish in color; smooth
|
| Growth habit |
annual
|
Common ragweed
| Cotyledons |
spread about 21 mm; broadly spatulate (spoon shaped) to short
oval, with broad petioles; veined at base on lower surface, not veined to
faintly veined on upper surface; thick and waxy, with dark spots on margin
of lower surface and sometimes on upper surface
|
| Leaves |
opposite; five lobed, with terminal lobe sometimes toothed;
branched midvein; long petioles; leaves and petioles densely hairy
|
| Hypocotyl |
purple to dark green in color
|
| Growth habit |
annual
|
Giant ragweed (Kinghead)
| Cotyledons |
spread about 50 mm; broadly spatulate (spoon shaped) to oval,
with broad petioles; triple veined at base on lower surface; midvein only
on upper surface; thick and waxy; spotted on margin of lower surface
|
| Leaves |
opposite; three lobed, with terminal lobes toothed; branched
midvein; petioles and leaves short, hairy
|
| Hypocotyl |
purple in color
|
| Growth habit |
annual
|
Marshelder
| Cotyledons |
spread about 11 mm; short oval, with broad petioles and blunt
tips
|
| Leaves |
opposite; narrowly ovate, with pointed tips; branched midvein;
leaves and petioles densely and coarsely hairy
|
| Hypocotyl |
often turns reddish
|
| Growth habit |
annual
|
White cockle
| Cotyledons |
spread about 22 mm; ovate
|
| Leaves |
opposite; oval to spatulate (spoon shaped) with pointed tips;
midvein on lower surface, absent or faint on upper surface; leaves and
petioles densely hairy, greenish-gray
|
| Hypocotyl |
short; greenish-gray; hairy
|
| Growth habit |
biennial or short-lived perennial |
Pennycress
| Cotyledons |
spread about 19 mm; short oval, with long and slender petioles |
| Leaves |
first leaves appear opposite, later alternate, several appearing
together to form a rosette; short ovate to short oval, with toothed margins
and long petioles; lightly branched midvein; garlic-like odor when crushed
|
| Hypocotyl |
short; smooth |
| Growth habit |
annual or winter annual |
Shepherd's-purse
| Cotyledons |
spread about 10 mm; oval to ovate, with medium-long petioles;
midvein none to faint on lower surface
|
| Leaves |
first leaves appear opposite, later alternate, becoming a rosette;
oval to ovate; midvein on lower surface; hairy
|
| Hypocotyl |
short
|
| Growth habit |
annual or winter annual
|
Produced by Communication and Educational Technology Services, University of
Minnesota Extension.
In accordance with the Americans with Disabilities Act, this material is available in alternative formats upon request. Please contact your University of Minnesota Extension office or the Extension Store at (800) 876-8636.
