COMPOSITAE 



COMPOSITE FAMILY 



GOLDEN RAGWORT. SQUAW WEED 



Senecio aureus L. 



This is probably the largest genus of plants, having at least 

 1200 species widely distributed throughout the north temper- 

 ate zone. At least three or four species besides the Squaw 

 Weed occur in Illinois. The 

 genus name Senecio comes 

 from the Latin senex meaning 

 an old man. 



The Golden Ragwort is found 

 in swamps, wet meadows and 

 moist thickets throughout Illi- 

 nois, northeastern United States 

 and southeastern Canada. It 

 blooms from May to August. 



It is a perennial that pro- 

 duces at the base a cluster of 

 simple rounded leaves with long 

 petioles. The slender stem grows 

 1-3 feet high, branching near the 

 top to produce a number of 

 heads of golden flowers. The 

 leaves toward the base of the 

 stem have short petioles and 

 are somewhat lobed, whereas the 

 higher and sessile stem leaves are variously cut and toothed. 



Each head consists of 8-1 5 pistillate ray flowers and a number 

 of perfect disk flowers. The involucre consists of a single row of 

 erect bracts with usually a few minute scales at the base. The 

 pappus, of many delicate smooth white hairs, persists and well 

 adapts the smooth akene fruits to wind dissemination. 



An immigrant annual of this genus, the Common Groundsel, 

 Senecio vulgaris L., is a weed on waste grounds. The hollow stem is 

 nearly without hairs, usually much branched, and 6-15 inches high. 

 The leaves are 2-6 inches long, pinnately cleft, the lower petioled 

 and the upper sessile or clasping at the base. It blooms from April 

 to October but does not produce ray flowers, so that the inflorescence 

 is much less conspicuous than that of the Golden Ragwort. Involucral 

 bracts are linear, with a few or several outer ones having black awl- 

 shaped tips The akenes have a coating of fine gray hairs and a white 

 pappus. 



381 



