Up to 4 ft. tall, rough-textured, branched and bushy; NO wings on upper stems
Alternate, gray-green, up to 8 in. long; most are pinnate-divided, dotted with resin and sometimes covered with small grayish hairs; upper leaves smaller and narrower with few to no lobes
White to purple, each located at the tip of a branch; base of flower is vase-shaped, 0.5 in. long, 0.3-0.5 in. wide and covered with bracts with dark, comb-like tips that give the appearance of spots (after which the weed is named)
Deep, stout taproot
Grows best on dry, well-drained soils; often infests rangelands, waste areas and roadsides; known to occur in Carson City, Clark, Douglas, Elko, Eureka, Humboldt, Lander, Lyon, Lincoln, Nye, Washoe and White Pine counties
Biennial; reproduces by seed and lateral roots
Several insect biological control agents are available Apply 2,4-D or dicamba in the rosette stage; apply clopyralid, picloram or aminopyralid between rosette and mid-bolt stages