Stem

Up to 4 ft. tall, stiff, highly branched, bushy and covered with hairs; NO wings on upper stems

Leaves

Alternate; 4-8 in. long, mostly pinnate-divided, covered with short grayish hairs and dotted with resin

Flower

Pink to purple, each located at the tip of a branch; base of flower is vase-shaped, 0.75-1 in. long, 0.25 in. wide and covered with stout, straw-colored spines 0.4-1 in. long

Root

Deep, stout taproot

Other

Grows best in sites with heavy, fertile soils; often infests rangelands, waste areas and roadsides; not known to occur in Nevada
Annual, biennial or perennial; reproduces by seed; older rosettes have a circle of straw-colored spines at the center
Closely resembles Iberian starthistle in everything except seed; seed of Iberian starthistle has plume of bristles extending from one end, purple starthistle does NOT

Control

Mowing plants in bud to flower stage can reduce seed production; repeated hand removal can be effective; DO NOT burn
Apply 2,4-D, clopyralid, dicamba, or glyphosate in the rosette stage; aminocyclopyrachlor, aminoyralid, picloram or sulfometuron preemergence to rosette stage

Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Purple Starthistle, Extension, University of Nevada, Reno, Field Guide

Extension Associated Contacts

Heidi Kratsch

Also of Interest:


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Division of Plant Health and Compliance-Plant Pathology Fact Sheets These fact sheets offer a variety of plant health and pathology information. Nevada Department of Agriculture (NDA) 2006, NDA (agri.nv.gov)

Associated Programs

Garden plant and pest sprayers image by Olga Seifutdinova from Getty Images

Integrated Pest Management

Integrated Pest Management program is a long-term management strategy that uses a combination of tactics to reduce pests to tolerable levels with potentially lower costs for the pest manager and minimal effect on the environment.

Master Gardeners of Washoe County

Master Gardeners provide free, research-based horticulture information to Nevadans.

Master Gardeners of Nevada

Program trains local gardeners to provide research-based horticulture information to Nevadans

Nevada Noxious Weed Field Guide – Purple Starthistle