486 



STRUCTURE AND LIFE HISTORIES 



{ligulate) corolla, formed by the fusion of the five petals, 

 as indicated by the five notches at the end (Fig. 372). 

 The tubuliflorae may have both tubular and ligulate 

 flowers, as in boneset (Eupatorium perjoliatum) or in white 

 daisy {Chrysanthemum leucanthemum) ^ or only tubular, as 

 in the burdock {Arctium, Fig. 371), or in the Canada thistle 



Fig. 371. — Inflorescence and flowers of the burdock {Arctium minus), 

 a, Inflorescences; h, longitudinal section of the same; c, bud of individual 

 flower; d, mature flower; sty, stigma; stig, style; a, ring of syngenesius 

 anthers; c, corolla; p, pappus (calyx); ov, ovary; e, mature seed. 



{Cirsium arvense). Among the liguliflorag may be men- 

 tioned chicory {Cichorium Intyhus, Fig. 372), dandelion 

 {Taraxacum), garden lettuce {Lactuca sativa), and others, 

 all of which possess a milky juice, or latex. The five stamens 

 (rarely four) are inserted on the corolla, and have their 

 anthers united in a tube {syngenesious) around the style. 



