194 THE STORY OF THE PLANTS. 



meadow-sweet, and with buttercup, as well as 

 with many of our garden flowers. When a 

 plant becomes perennial, it is a mere question of 

 its own convenience whether it chooses to produce 

 a thick and woody stem, like trees and bushes, 

 or to lay up material in underground roots, 

 stocks, and branches, like the potato, the dahlia, 

 the lilies, the bulbous buttercup, the crocus, the 

 iris, the Jerusalem artichoke, and the meadow 

 orchis. 



Ordinary people divide most plants into three 

 groups herbs, shrubs, and trees. But I think 

 you will have seen from what I have just said, 

 that in every great family of plants different kinds 

 have found it worth while to adopt any one of 

 these forms at will, according to circumstances. 

 Trees, in other words, do not form a natural 

 group by themselves ; any family of plant may 

 happen to develop a tree-like species. Thus 

 the herb-like clover and the tall tree-like labur- 

 num are closely related peaflowers. Most of 

 the composites are mere herbs or shrubs, but a 

 very few of them in the South Sea Islands have 

 grown into large and much-branched trees. The 

 grasses are mainly herbs ; but some of them, 

 like the bamboos, have developed tall and tree- 

 like stems, much branched and feathery. 



Take the single family of the roses, for example, 

 so familiar to most of us ; some of them are mere 

 annual weeds, like the tiny parsley-piert that 

 occurs as a pest in every garden. Others, again, 

 are perennials with low tufted stems, like the 

 strawberry ; or creeping, like the cinquefoil ; or 

 rising into a spike, like the burnet and the agri- 



