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

Stem

  • Up to 5 ft. tall, stout, lacks hair (glabrous) and hollow except at nodes; usually with purple streaks; often branched
 

Leaves

  • Pinnate-compound; leaflets are lance-shaped, 1-4 in. long and lack hair; edges (margins) are toothed 
 

Flower

  • Small, white and arranged in umbrella-like clusters at end of a stalk
 

Root

  • Swollen taproot at stem base that can be cut open to reveal multiple narrow, hollow, horizontal chambers; fluid released from cut stem bases is orange-yellow or brown, has the odor of parsnip and is highly toxic
 

Other

  • Grows best in moist soils; often found in crop fields, roadsides, waste areas and along waterways; known to occur in Douglas and Lyon counties; native to North America
  • Perennial; reproduces by seed
  • Highly toxic to animals and humans, even in small quantities
 

Control

  • Repeated cultivation or hand-removal can be effective; avoid contact with skin
  • Apply 2,4-D, glyphosate, or MCPA to actively growing plants

Learn more about the author(s)

 

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