Fig. 3. — C'nicus arvensis. Floral development: A, receptacle almost evenly convex; H, 

 appearance of papilla to become flowers ; (?, a single papilla more advanced, show- 

 ing beginning of corolla; Z>, corolla more prominent; E, stamens distinguishable; 

 F^ carpels and pappus (calyx) evident; G, carpels beginning to form cavity of 

 ovary; //, ovule readily distinguishable; /, ovule showing megaspore mother-cell 

 and single thick integument: J, bract of involucre; c, corolla; s, stamen; t>, carpel; 

 jo, pappus (calyx). A-H x 50 ; / x 100. 



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