THE FLOWER 



41 



as in Clematis. In the reduplicate they are turned outward, as the 

 sepals of Althea. 



Vexillary, the variety shown in the corolla of the Pea, where the 

 two lower petals are overlapped by two lateral ones, and the four in 

 turn overlapped by the larger upper ones. 



Contorted, where one margin is invariably exterior and the other 

 interior, giving the bud a twisted appearance, as in the Oleander and 

 Phlox. 



The Flower 



The flower is a shoot which has undergone a metamorphosis so as to 

 serve as a means for the propagation of the individual. 



Fig. 30. — Diagrams of floral structures. A, shows the relations of the floral 

 parts in a hj^ogynous flower. B, The same in a perigynous flower. C, The 

 same in an epigynous flower. D, A stamen. E, A simple pistil in longitudinal 

 section. F, The same in cross-section. G, Transitonal forms between true petals 

 (left) and true stamens (right). H, Slight union of two carpels to form a compound 

 pistil. / and /, Union of carpels more complete. K and L, Cross-sections of com- 

 pound pistils, of three carpels. In B: a, stamen; b, petal; c, sepal; d, pistil; e, 

 receptacle; /, pedicel. In D: a, anther ceU; 6, connective; c, filament. In E: a, 

 stigma; h, style; c, ovules; d, ovary. {From Hamaker.) 



The parts of the flower are Sepals, Petals, Stamens, and Carpels, 

 all of which are inserted upon a shortened axis called the Receptacle 

 or Torus. This is usually flat or convex, but may be conical and fleshy 

 as in the Strawberry ; concave as in the Rose and Fig; or show a disc-like 

 modification, as in the Orange. The axis of a flower cluster, if short, is 

 sometimes called a common receptacle, as in the floral axes of the Dande- 

 lion and Lettuce. 



