johnsongrass
(Sorghum halepense (L.) Pers.)

Overview

Appearance

Sorghum halepense is a tall (up to 8 ft. [2.4 m]), rhizomatous, perennial grass that invades open areas throughout the United States.

Foliage

The 2 ft. (0.6 m) long, lanceolate leaves are arranged alternately along a stout, hairless, somewhat upward branching stem and have distinct, white midribs.

Flowers

Flowers occur in a loose, spreading, purplish panicle.

Fruit

Fruits are also produced in a panicle. Seeds form in the sessile spikelets.

Ecological Threat

Sorghum halepense is adapted to a wide variety of habitats including open forests, old fields, ditches and wetlands. It spreads aggressively and can form dense colonies which displace native vegetation and restrict tree seedling establishment. Sorghum halepense has naturalized throughout the world, but it is thought to be native to the Mediterranean region. It was first introduced into the United States in the early 1800s as a forage crop.

Resources

• Invasive Plants of the Eastern U.S. - University of Georgia
• Element Stewardship Abstract - The Nature Conservancy
• Fire Effects Information System - USDA Forest Service
• Federal Noxious Weed Disseminules of the U.S. - USDA-APHIS
• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Alabama Invasive Plant Council
• Arizona Noxious Weeds
• California Noxious Weeds
• Colorado Noxious Weeds
• Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, 1994.
• Delaware Noxious Weeds
• Delaware Regulations for Noxious Weed Control
• Georgia Exotic Pest Plant Council - Category 3
• Idaho Noxious Weeds
• Illinois Noxious Weeds
• Indiana Invasive Species Council - Invasive Plant List
• Indiana Noxious Weeds
• Invasive Plant Species of West Virginia
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• Kansas Noxious Weeds
• Kentucky Exotic Pest Plant Council - Severe Threat
• Kentucky Noxious Weeds
• Maryland Code and Regulations Noxious Weed & Seed Law
• Maryland Department of Natural Resources Policy: Restriction on Planting Exotic Invasive Plants
• Maryland Invasive Species Council - Invasive Species of Concern in Maryland
• Maryland Noxious Weeds
• Michigan Noxious Weeds
• Minnesota Noxious Weeds
• Missouri Noxious Weeds
• Missouri SRISP Species List
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• Nevada Noxious Weeds
• Non-Native Invasive Plants of the City of Alexandria, Virginia
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Ohio Noxious Weeds
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Pennsylvania Noxious Weeds
• Pennsylvania Regulations for Controlled Plants and Noxious Weeds
• South Carolina Exotic Pest Plant Council
• Tennessee Exotic Pest Plant Council
• Utah Noxious Weeds - Contain
• Virginia Invasive Plant Species List
• Virginia Invasive Species Management Plan 2012
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Department of Agriculture Regulations Governing the Distribution of Plant Materials
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• West Virginia Noxious Weeds
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References