Atypical branching of foxtail (Setaria spp.) panicles in west-central Kansas

Taxonomists describe panicles of green and yellow foxtail (Setaria viridis (L.) and S. glauca (L.) Beauv., respectively) as dense, contracted, narrow and cylindrical. However, a By survey near Hays, Kansas documented inflores cences of green and yellow foxtail that were divided into two to four or mo re elongated segments. Those panicles were forked cr digitate rather than a single compact cylinder. Anomalous panicles were always found on plants ha ting several normal heads. Branched morphology was infrequent (<1 head in 1 0,000), but was observed in 1993 and 1995-1998. Before 1998 Kansas collecti ons of foxtail specimens with abnormal panicles were limited to a 1600 X 32 00 m area in central Ellis Country. Observations during 1998 increased the known geographic distribution in Kansas to a 3200 X 3600 m area. Seed colle cted from branched panicles of both species and grown in greenhouse conditi ons did not produce plants with any aberrant inflorescences. Occurrence of deviant green or yellow foxtail panicles did not correlate with herbicide u sage or drift.