Sentence:  <WSD>Scramblers</WSD> and palms that climb with the aid of hook-bearing leaves or modified inflorescences (i.e. Desmoncus and the lepidocaryoid rattans) climbed most successfully in dense clusters of small diameter supports, such as occur on the edge of treefall gaps. 
Meaning of the word marked with <WSD> tags:  A vine that does not attach itself to its supports.