johnsongrass
Sorghum halepense                                        

Identifying Characteristics:

Seed:  long, oval seeds; knobbed rachilla with hairs; ridged surface; shiny; dark reddish brown in color

Seedling:  leaves rolled in whorl; glabrous sheaths and leaves; fringed, membranous ligule; no auricles; hairs may be present at base of leaf; prominent white midvein

Mature Plant: erect, bunch-type growth habit; erect, open panicle with many branches; 2-flowered spikelets with one fertile; reddish tint

Method of Propagation: seed, rhizomes

Life Cycle: warm-season perennial

Similar Species: grain sorghum - the panicle of johnsongrass is a more open panicle than grain sorghum, also grain sorghum is a shorter and stouter plant

References: Abaye, A. Ozzie. "Identification & Adaption: Common Grasses, Legumes & Non-leguminous Forbs of the Eastern United States."
Bryson, Charles T. & Michael S DeFelice. "Weeds of the Midwestern United States & Central Canada."