70 BIOLOGY FOR BEGINNERS 



broad-shouldered and broad-leaved giants, must either get a start 

 before the leaves come in the spring or else must have learned to 

 live with very little light. 



Forked Branching. Indefinite Branching. The growth of the 

 terminal bud may be checked by bearing flowers. If so, the branch 

 usually forks in a Y shape, producing round-topped plants, such as 

 the horse-chestnut and magnolia. In some shrubs the terminal 

 bud is unprotected for winter, hence is killed back and thus produces 



FIQ. 14. Creeping stem of the water fern (marsilia). From Atkinson. 



a very irregular type of branching, called indefinite. This is well 

 illustrated by the sumach. 



MODIFICATION OF STEMS 



As would be expected, stems are variously adapted to suit 

 different conditions and functions, thus giving rise to many forms. 



Shortened Stems. In some plants like the dandelion, the stern 

 is so shortened that the leaves seem to come in a rosette, directly 

 from the top of the root. On this account, the term " stemless " 

 is sometimes applied to such cases. These low-growing plants 

 have many advantages, among which may be mentioned : 



