GUILDS 1^3 



round ami brinjj thciii into a favourable situation as regards light. They 

 iclude wootl)' plants with evergreen leaves as well as deciduous climbin<T 

 u'ubs, also forms with herbaceous stems that exist for one vegetative 

 :ason only, or are perennial in their subterranean organs '. That lianes 

 imb upon and around other plants is due only to the fact that, in nature, 

 e plant kingdom alone provides objects ha\ing the necessary form as 

 pports ; it is the form alone that is of importance and not the chemical 

 iturc of the support, for, as cultivated plants show, the support may be 

 mposed of the most miscellaneous materials. Certain forms of lianes do 

 cur naturally as rock-climbers, but the number of these is relatively small. 

 Lianes may be arranged in four groups, according to their mode of 

 mbing ; the\- are, scramblers, root-climbers, tzi'incrs, tendril-climbers. 



Scramblers. 



The majorit)- of scramblers are shrubs distinguishable, in the simplest 

 ses, from other shrubs only b)' their long straggling branches, which 

 pport themselves on other branches without fastening in any active 

 mner. The climbing of these plants is often assisted by prickles or 

 )rns, without our being able to regard the latter as adaptations to a 

 mbing mode of life, for example in roses and brambles. Whilst the 

 jority of scramblers represent the lowest degree of liane, there are 



ong them forms with very complete, even if passive, contrivances, for 

 imple the palm-lianes of the tropical forests. These will be described 



eafter. 



Rcot-climbers. 



These form a small group, the representatives of which grow upwards 

 means of subaerial roots fixed to the support. .Such fixing roots are 



)rt and thin as in ivy, or they may attain the thickness of a quill with 



ength of 2-3 decimeters and wind like hoops round cylindrical supports, 

 h vigorous development of fixing-roots is exhibited only by tropical 



ms like Vanilla and many Araceae, such as Monstera and Philodendron. 



Twiners. 



n twining plants the axes grow spirally around slender supports in virtue 

 their unilateral transverse geotropism, which later on passes over into 

 ;ative geotropism. To this group belong a number of well-known 

 baceous climbers, such as hop, kidney-bean, bindweed, also many woody 

 ics, for example, honeysuckle, the widely cultivated Wistaria chinensis, 

 1 species of Aristolochia. 



Tendril-climbers. 



This group is richest in forms. Climbing is rendered possible amongst 

 ni by the possession of irritable organs, which, when in contact with 



^ H. Schenck, I, p. 2. 



