DEFINITION 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 
Fic. 82. — Pistillate flower and fruit of a Hickory (Carya). A and B, ex- 
terior and interior views of the flower. C,the nut. 6, 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. 
Fic. 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 (0) and the bracts (b). 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- 
