262 



BOTANY OF CROP PLANTS 



reality stipules belonging to leaves which, normally, do 

 not develop. Each of the lateral branches bears four pis- 

 tillate flowers. Below each flower is a single bracteole 

 (small bract). Hence, examination of a single lateral axis 

 or branch shows it to be made up of the following parts, 

 from below upwards: (i) two bract-like stipules; (2) brac- 



— bract-Jike 



stipule 



^bracteole 



Fig. 104. — Hop (Humulus lupvdus). A, single staminate flower; B, two 

 pistillate flowers with bracteoles and bract-like stipule. (B after Wossidlo.) 



teole and first flower; (3) bracteole and second flower; (4) 

 bracteole and third flower; (5) bracteole and fourth flower. 

 Flowers. — The staminate flowers (Fig. 104, A) measure 

 about 6 millimeters in diameter. They have a five-parted 

 calyx, no corolla, and five stamens opposite the calyx lobes. 

 Each pistillate flower (Fig. 104, B) is subtended by a single 

 bracteole (Fig. 105, A) that partially encloses it at maturity. 

 It has a single ovary surrounded by a cup-shaped perianth. 

 There is one style with two long stigmas, which are covered 

 their full length with papillae 



