HOME PLANTS AND THEIR WAYS. 



17 



gained over a mere hook. A leaf might be made to catch 

 on to a neighboring twig by its bent stalk in such a way 

 that, although it managed to stay where it was, it could 



Clasping Leaves. 



bear none of the weight of the plant, and would be liable to 

 be displaced by a strong wind or other disturbance. But 

 when the stalk of the leaf has curled round the twig, noth- 

 ing could displace it, and it could take its share in the work 

 of sustaining tiie plant. 



5. The genus Tropceolum, whose cultivated species are 

 often called nasturtiums, also consists of leaf-climbing 

 plants, which climb like clematis by grasping neighboring 

 objects with their leaf-stalks. In some species we find 

 climbing organs developed, which can not logically be dis- 

 tinguished from tendrils ; they consist of little filaments, 

 not green like a leaf, but colored like the stem. Their 

 tips are a little flattened and furrowed, but never develop 

 into leaves ; and these filaments are sensitive to a touch, 

 and bend toward a touching object, which they clasp se- 

 curely. Filaments of this kind are borne by the young 

 plant, but it subsequently produces filaments with slightly 



