Sommier & Levier (Giant hogweed )
Family: Apiaceae (Carrot Family)
Duration: Biennial, Perennial
Description: Giant hogweed is a biennial or perennial herb in the carrot family (Apiaceae), growing 15 to 20 feet in height with stout dark reddish-purple stems and spotted leaf stalks. Hollow stalks and stem produce sturdy bristles. The compound leaves with three leaflets may expand to five feet in breadth.
History: Giant hogweed was introduced from Eurasia around 1917 for use as an ornamental plant.
Biology & Spread: The inflorescence is a broad flat-topped umbel composed of many small white florets. Each inflorescence may attain a diameter of 2-1/2 feet. The florets produce large elliptic dry fruits marked with brown swollen resin canals up to 1 mm in diameter. It flowers from mid-June to mid-July and then produces large flattened elliptic dry seeds with approximately 1500 seeds per flower head.
Ecological Threat: Giant Hogweed is an aggressive competitor. Because of its size and rapid growth, it
out-competes native plant species, reducing the amount of suitable habitat available for wildlife. Giant Hogweed dies back during the winter months, leaving bare ground that can lead to an increase in soil erosion on riverbanks and steep slopes.
US Habitat: Giant hogweed can invade a variety of habitats but prefers moist, disturbed soils such as riverbanks, ditches and railroad right-of-ways.
Resembles/Alternatives: Joe Pye weed (Eupatorium dubium or fistulosum), boneset or white snake root (Eupatorium perfoliatum or rugosum), elderberry (Sambucus canadensis), southern arrowwood (Viburnum dentatum)
Management: Do not cultivate, plant, purchase, or transplant this plant. It is very difficult to control. If found, notify your state Department of Agriculture, who will handle control measures. Use protective clothing, gloves and face visor or similar to undertake any cutting or removal of this species.
USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS. MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.
Last Updated: 2013-12-05 by LBJWFC