<b>Harold F. Heady</b> is professor emeritus at the University of California at Berkeley. He was awarded the Berkeley Citation in 1991 in recognition of his long and preeminent career in range management. <b>R. Dennis Child</b> is National Program Leader, Range, with the USDA Agricultural Research Service in Beltsville, Maryland.
Leafy spurge; snakeweeds; thistles; knapweeds; woody species; other noxious weeds.