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Summer Annual Weed Seedlings

On this page
  • Black nightshade
  • Hairy nightshade
  • Groundcherries
  • Common cocklebur
  • Annual sowthistle
  • Common sunflower
  • Kochia
  • Common lambsquarters
  • Russian thistle
  • Redroot pigweed
  • Common knotweed
  • Common purslane
  • Longspine sandbur

Use the photos below to identify weeds in the field. Names link to information on identification and biology.

Click on photos to enlarge
				nightshade seedling.
Black nightshade
(Solanum nigrum): Nightshade family; summer annual or short-lived perennial; seed leaves oval and pointed; first true leaves spade shaped with smooth edges; lower surfaces often purple; petioles stems and leaves with some hairs.
				nightshade seedling.
Hairy nightshade
(Solanum sarrachoides): Nightshade family; summer annual; seed leaves narrow, small, and lance shaped with very short soft hairs along edges; first true leaves with wavy edges and prominent veins.
(Physalis spp.): Nightshade family; summer annual or perennial; seed leaves yellow green to gray green; first leaves oval to triangular, with smooth or slightly wavy margins, and a strong odor when crushed.
Seedling of common 
Common cocklebur
(Xanthium strumarium): Sunflower family; summer annual; seed leaves bright green, shiny on upper surface, pointed, and about 6 times longer than wide; true leaves on seedlings notched on margins and taper to leaf tip; bur may remain attached to base of seedling.
Sowthistle seedling
Annual sowthistle
(Sonchus oleraceus): Sunflower family; summer or winter annual; seed leaves markedly stalked, almost spoon-shaped, rounded at tip and often have grayish powdery bloom; injured tissue bleeds milky white latex.
Common sunflower
Common sunflower
(Helianthus annuus): Sunflower family; summer annual; seed leaves oblong, joined at base, smooth; first true leaves opposite, elliptical, dull green, covered with short bristly hairs rough to the touch; later leaves alternate, elliptical to lance shaped.
(Kochia scoparia): Goosefoot family; summer annual; seed leaves linear to narrowly lance shaped, smooth; true leaves narrowly lance shaped, gray-green, covered with soft white hairs, forming a small rosette.
				of common lambsquarters, Chenopodium album.
Common lambsquarters
(Chenopodium album): Goosefoot family; summer annual; seed leaves are narrow, with nearly parallel sides; seed leaves and early true leaves dull blue green above and often purple below; young leaves have mealy appearance from coating of fine translucent granules.
Russian thistle seedlign
Russian thistle
(Salsola tragus): Goosefoot family; summer annual; cotyledons and first true leaves long and thin; first leaves are fleshy, soft, and weakly spine-tipped; stems slender and flexible, often with reddish purple striations along their length.
				pigweed seedlings.
Redroot pigweed
(Amaranthus retroflexus): Pigweed family; summer annual; seed leaves long and narrow with red undersides; first true leaves with notched tips and much broader than seed leaves.
Seedling of California burclover
Common knotweed
(Polygonum arenastrum): Knotweed family; annual or short-lived perennial, germinates during fall or spring; seed leaves are long, very narrow, rounded at the tip and light green with a white cast; true leaves are much broader, emerging from an encircling, membranous sheath at the leaf base.
Seedling of common 
					purslane, Portulaca oleracea.
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.
Longspine sandbur
Longspine sandbur
(Cenchrus longispinus): Grass family; summer annual; seedling leaves are flattened, have a purplish tinge at the bottom; distinctive identification characteristic is the bur, from which the young plant emerges, found by digging carefully around the roots.

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