DICOTYLEDONOUS PLANTS 235 
with usually 5 stamens inserted on the corolla, the anthers 
united into a tube which surrounds the style (Fig. 23, V). 
Calyx with its tube adnate to the ovary, the limb sometimes 
wanting, when present taking the form of scales, bristles, etc., 
known as pappus (Fig. 24, II, III). Corolla either strap- 
shaped (Fig. 25, 7) or tubular (Fig. 23, V), in the former case 
I II Ul 
Fig. 23. — Bachelor’s Button. 
I, vertical section of the receptacle; II, style and forked stigma (magnified) ; 
Ill, corolla, united anthers and stigma (magnified) ; 1V, pistil (magnified) ; 
pap, pappus; ak,akene; V, tubular flower cut vertically (magnified), showing 
anther-tube, traversed by the style ; /, lobe of corolla. 
often 5-toothed, in the latter usually 5-lobed. Style 2-cleft 
above. Fruit an akene, often provided with means of trans- 
portation (Part II, Ch. XXIX). The largest family of 
flowering plants and among the most specialized for insect 
pollination. The genera of the northern United States are 
divided into two suborders: I. TusuirLor, corolla of the 
perfect flowers tubular and 5-lobed ; II. LicutirLoR, corollas 
all strap-shaped and flowers all perfect. 
