Johnsongrass - Sorghum halepense (L.) Pers.
David J. Moorhead, The University of Georgia, October 2003
Plant: Erect rhizomatous, perennial graminoid, 1-3m tall, branched from base with broad, long green leaves with prominent white midveins, from scaly sharp rhizomes and forming dense stands. Rhizomes can be as much as 1 cm in diameter and 2 m long. Plant toxic (prussic acid or hydrocyanic acid), if fertilized heavily or drought stricken.
Stem (culm): Stout, hairless, pink to rusty red near base, somewhat upward branching.
Leaves: Alternate, long- lanceolate, 20-60 cm long and 1-3 cm wide, green, with white midvein above, margins rough, prominent white-fringed membranous ligule at base of leaf, hairless except on white flared throat and a hair patch behind the ligule.
Flowers: Apr. - Nov. Open spreading purplish panicle, 15-50 cm long, with numerous whorled projecting branches being shorter in the upper portion, spikelets in pairs at the end of finer branchlets, one spikelet stemless and ovoid and the stemmed and narrow, 4-6 mm long, husks shiny and short hairy, either green, yellow, purple, or black, tipped with a thread-like awn, 5-13 mm long or absent.
Seeds: May- Mar. Awned, ovoid seeds are dark reddish- brown, released within the husks.
Range: Exotic and naturalized from Mediterranean area. CA to FL and north to MA and west to NE and OK.
Ecology: Occurs as dense colonies in old fields and along field margins and right-of-ways, where it invades new forest plantations, open forests, and forest openings. Highly competitive with planted and natural tree seedlings. Persists and colonizes by rhizomes and spreads by seeds.
Recommended Control Procedures
James H. Miller, USDA Forest Service, Auburn, AL. personal correspondence
Miller, J.H. and K.V. Miller. 1999. Forest Plants of the Southeast and Their Wildlife Uses. Southern Weed Science Society. Auburn, AL. Craftmaster Printers.
Smith, T.E.(ed.) 1993. Missouri vegetation management manual. Missouri Department of Conservation. pp. 68-77.
Snyder, S. A. 1992. Sorghum halepense. In: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2003, October). Fire Effects Information System, [Online]. Available: http://www.fs.fed.us/database/feis/ [9 October 2003].
|Bargeron, C.T., D.J. Moorhead, G.K. Douce, R.C. Reardon & A.E. Miller |
(Tech. Coordinators). 2003. Invasive Plants of the Eastern U.S.:
Identification and Control. USDA Forest Service - Forest Health
Technology Enterprise Team. Morgantown, WV USA. FHTET-2003-08.