xiv TERMS USED IN DESCRIBING THE FLOWER 191 



EXPT. 1 72. Examine the flower of the Daffodil and describe it, taking 

 its organs in the same order as above. 



SUMMARY. 



Terms used to describe the shape and arrangement of the organs of 

 flowers 



The torus is the upper part of the flower stem upon which the floral 

 leaves are placed. Its shape varies. 



A complete flower is one in which calyx, corolla, stamens and pistil 

 are all present. 



An incomplete flower is one where one or more of the floral whorls 

 are absent. 



A perfect flower will contain stamens and pistil. 



An imperfect flower will only contain stamens or pistil. 



An actinomorphic flower is one which can be divided into equal 

 halves in any plane. 



A zygomorphic flower can only be divided into equal halves in one 

 plane. 



The anterior parts of the flower face the bract in the axis of which 

 the flower stands. The posterior parts of the flower face the axis of 

 the inflorescences. 



Shapes of flowers. The following list gives the principal shapes 

 of the flowers 



Cruciform, papilionaceous, spurred, tubular, rotate, funnel-shaped, 

 ligulate, campanulate, personate, labiate. 



Cohesion is a term used to describe union between similar parts. 

 Adhesion is used to describe union between dissimilar parts. 



The calyx may be polysepaloiis or gamosepalous ; inferior or superior. 



The corolla maybe/0/j>/<?te/0.y or gamopetalous ; hypogynous, perigy- 

 nous, or epigynous. 



The androecium is composed of the whole collection of stamens of a 

 single flower. 



The cohesion of the stamens may be monadelphous, diadelphous, 

 polyadelphous, syngenesious. 



The adhesion of the stamens may be hypogynous, perigynous, epipe- 

 talous, epigynous, gynandrous. 



Thefl/awent may be long or short. 



The anther may be versatile, basifixtd, dorsifixed. 



The gynoacium is composed of the whole collection of carpels of a 

 single flower. There are three kinds of pistils monocarpous, apocar- 

 pous, syncarpous. 



The Placentation, or the arrangement of the ovules in the ovary 

 may be parietal, axile, free-central, basal, marginal. 



The term perianth is used when the two outer whorls of a flower are 

 alike as in most monocotyledons. 



The floral formula represents by letters, figures, lines and brackets, 

 the parts of a flower and their position. 



