DEFINlTIOxN OF A FRUIT 



81 



pappus, consisting of hair-like structures which correspond to 

 the calyx of the ordinary type of flower, remains as a part of the 

 fruit, forming a parachute-like arrangement which enables the 



Fig. 82. — Pistillate flower and fruit of a Hickory (Carya). A and B, ex- 

 terior and interior views of the flower. C, the nut. b, bracts surrounding the 

 pistil (p); 0, ovary. Flower much enlarged but fruit reduced. 



fruit to float in the air. Sometimes, as in the Spanish Needles, 

 the calyx remains on the fruit as spiny appendages. In the case 

 of the Birch, Elm, Ash, and Maple, the fruit known as a samara 

 or key-fruit has wing-like structures which are outgrowths from 

 the ovary wall. 



Fig. 83. — Flower and fruit of an Oak (Quercus). A, pistillate flower, 

 showing the bracts (6) which surround the ovary. B, section of the flower, 

 showing the ovary (o) and the bracts (6). C, acorn, showing the ovary and 

 cup. s, stigmas. Flower much enlarged but fruit nearly natural size. 



Definition of a Fruit. — From an examination of the above 

 types of fruits, it follows that a fruit may consist of: (1) simply 

 the ovary either dry or fleshy; (2) ovary or ovaries and recep- 



