Malta starthistle (Centaurea melitensis)


Category A Weed

Sunflower family (Asteraceae)

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Stem

  • 1-3 ft. tall, stiff, wiry and usually branched; wings (less than 0.1 in. wide) created by leaf bases that extend down the stem

    Leaves

    • Gray-green, 0.75-6 in. long and densely covered with fine hairs

    • Rosette leaves are oval to strap-like (linear) with smooth to deeply lobed edges (margins); stem leaves are alternate, strap-like to oblong with smooth, toothed or wavy edges

      Flower

      • Yellow, located at branch tips or axils in groups of 1-3; base of flower is vase-shaped, 0.3-0.6 in. diameter and covered with cotton-like hairs and stout, purple-to-brown colored spines (0.2- 0.6 in. long)

        Root

        • Shallow taproot

          Other

          • Often infests rangeland, pastures, crop fields, waste areas and roadsides; known to occur in Clark, Lincoln and Nye counties

          • Annual; reproduces by seed

          •  Also known as tocalote

            Control

            • Grazing, mowing, burning and cultivation can be effective if done prior to seed production

            • Apply aminopyralid, 2,4-D, clopyralid or dicamba from rosette through bolting; apply picloram from rosette through bud stages

              Images

              Malta Starthistle Flower
              Flower
              Malta Starthistle Flower 2
              Flower 2
              Malta Starthistle Rosette
              Rosette
              Malta Starthistle Seedling
              Seedling
                Nevada Noxious Weed Field Guide
              Nevada Noxious Weed Guide