Prickly lettuce (Lactuca serriola) can be a summer annual or biennial. The woody stems of this plant are hollow, and form in the middle of a basal rosette of leaves. Leaves are deeply lobed, and clasp the base of the stem. The leaf shape is distinctive, with the indentation between lobes forming a "C" shape. Leaves are also oriented at an angle to the stem, with spines on the midrib and base of the leaf. Prickly lettuce has yellow flowers, but these can appear to be white from a distance due to the wooly hairs (pappus) on each seed. This weed is most common in row crops and roadside areas.

Proper turf management is important for biennial broadleaf weed control. Maintain a dense, actively growing turf through proper mowing, fertilizing, and watering practices. Mow at the proper height for your selected adapted turfgrass. Coring and traffic control reduce compaction and encourage desirable turfgrass competition. It is best to control this biennial broadleaf weed in spring or fall, if actively growing at these times.

• GROWTH SEASON / LIFE CYCLE
  • summer annual or biennial weed
• GROWTH HABIT
  • early in the season it is a basal rosette, and then produces an upright stem in late summer
• LEAFLET NUMBER
  • one
    Figure 1, Figure 2
• LEAF MARGIN
  • lobed
    Figure 3, Figure 4
• LEAF HAIRS
  • prickles are found on the midvein on the lower surface of the leaf
• LEAF / LEAFLET SHAPE
  • long and linear leaves with rounded notches in leaf margin
• LEAF WIDTH
  • ¹⁄₂ - 2 inches
• LEAF VENATION
  • pinnate
• LEAF ARRANGEMENT
  • alternate
• FLOWER COLOR
  • yellow
• ROOT TYPE
  • taproot
    Figure 5, Figure 6

Figure 1. Prickly lettuce leaflet number.

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Figure 1. Prickly lettuce leaflet number.

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Figure 2. Prickly lettuce leaflet number.

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Figure 2. Prickly lettuce leaflet number.

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Figure 3. Prickly lettuce leaf margin.

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Figure 3. Prickly lettuce leaf margin.

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Figure 4. Prickly lettuce leaf margin.

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Figure 4. Prickly lettuce leaf margin.

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Figure 5. Prickly lettuce root type.

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Figure 5. Prickly lettuce root type.

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Figure 6. Prickly lettuce root type.

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Figure 6. Prickly lettuce root type.

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