54 



tQe stem 



39. The stem aiirl leaves nf Onlium, or 

 Bedstraw, studded with backward 

 pointiiij^ hooks (magnified). 



(Tiilium (Fig. 39), catcliing on leaves and branche.s, [ire- 

 vent these climl)ers from slipjung from their supports. 



If we attempt to pull 

 a tangle of Galium away 

 from the foliage of the 

 herbs and shrubs over 

 which it runs, the plant 

 itself is torn in pieces 

 before we succeed in 

 dislodging it. 



77. Of special organs 

 for climbing, the clinging 

 rootlets of the Trumpet 

 Creeper have already 

 been descriljed. Letives, and parts of leaves serving the 

 same gciiertd purpose, but adapted in a nincii more 

 remarl^alik' manner to a climljing htdjit, will be descril)ed 

 ill tlie iie.\t clKqiter. In the list of specialized climl)iiig 

 itrgans tlicrc still remain certain stems, modified into 

 either adherent or twining tendrils. 



78. Adhesive disks. — The Virginia Creeper illustrates 

 the iirst ease. Tlie tips of certain branches are flattened 

 into disks AA'ith an 

 adliesive face (Fig. 

 40). This is applied 

 to the su[)[iorting 

 i.ibject, til which it l)e- 

 ciimes firmly glued. 

 Then a sliortening 

 (if the branches by 

 iMiiliiig lirings up the 

 •'■i-iiwing shodt close 



40. Tendrils of Virginia Creeper. 



to the support. This is an adaptation to climbing mural 

 rocks and -walls or the trunks of trees, to which the 

 vine would not be able to cling by means of twining 

 tendrils. 



79. Twining tendrils. — Some tendrils are leaves or parts 

 of leaves, as those of Cubixa (Fig. 73). Tlie nature of a 



