148 HANDBOOK OF NATURE STUDY 



11. The flowers of the Bur Oak. 



Flowers rather late in May or early in June, when the 

 leaves are about one-third full grown; sterile flowers in 

 little clusters on thread-like catkins ; fertile flowers on slen- 

 der stalks from leaf -axils ; fruit maturing the first season. 



FIG. 34. BUR OAK. a, twig with leaves and young acorns ; 6, starainate 

 flowers ; c, pistillate flowers in the leaf-axils. All reduced. 



