62 



THE BOOK OF NATURE STUDY 



by means of creeping underground stems. In Fig. 32 the nodes (11) 

 of the underground stem of Solomon's Seal from which the roots 

 are given off are well marked ; the internodes (inf) are very 

 short, because the nodes are crowded together. The new plant 

 arises from the bud (&). The leaf -scars, showing the position of 



the leaves, are shaded. These leaves 

 are scale-leaves and protect the tip 

 of the growing stem. They must not 

 be confused with the green foliage- 

 leaves, which are borne on the aerial, 

 and not on the underground stem. 

 The underground stem of the Iris 

 very closely resembles that of Solo- 

 nion's Seal. It is fleshy, and bears 

 parallel leaf-scars, but in this plant 

 the leaf-scars represent the basis of 

 the foliage-leaves. Both these plants 

 come up in larger clumps year by 

 year, and new plants are easily ob- 

 tained from them by the process of 



separation 



,* , , 



Strawberries are propagated by 

 stems creeping along above the ground. These stems are called 

 runners, and grow out in the axils of the main plant. That 

 they are stems is clear, because they bear small leaves and end 

 in buds. From these buds foliage-leaves arise, and at the base 

 of the bud roots are developed, thus a separate plant is formed. 

 This plant in its turn may become the parent of others, by 

 producing runners. 



With the Strawberry may be compared the Gooseberry. The 

 branches of this latter plant bend down, roots are formed at the 

 end of the branches, which become detached and form independent 

 plants. The suckers of Raspberries are also of the nature of 

 stems. 



(ii.) By bulbs. A bulb consists of a short conical stem portion, 

 and of leaf-structures borne by the stem. These latter occupy 

 the greater part of the bulb. In some bulbs the leaf-structures 

 are merely the basal portions of green leaves, the blades of which 



FIG. 32. Underground stem, Solo- 



mon's Seal. , node ; */, intei- 

 node ; &, bud. 



