Note 84 — Chapter III · Tendril-Bearers.

Never having had the opportunity of examining tendrils produced by the modification of branches, I spoke doubtfully about them in this essay when originally published. But since then Fritz Müller has described (Journal of Linn. Soc. vol. ix. p. 344) many striking cases in South Brazil. In speaking of plants which climb by the aid of their branches, more or less modified, he states that the following stages of development can be traced: (1.) Plants supporting themselves simply by their branches stretched out at right angles—for example, Chiococca. (2.) Plants clasping a support with their unmodified branches, as with Securidaca. (3.) Plants climbing by the extremities of their branches which appear like tendrils, as is the case according to Endlicher with Helinus. (4.) Plants with their branches much modified and temporarily converted into tendrils, but which may be again transformed into branches, as with certain Papilionaceous plants. (5.) Plants with their branches forming true tendrils, and used exclusively for climbing—as with Strychnos and Caulotretus. Even the unmodified branches become much thickened when they wind round a support. I may add that Mr. Thwaites sent me from Ceylon a specimen of an Acacia which had climbed up the trunk of a rather large tree, by the aid of tendril-like, curved or convoluted branchlets, arrested in their growth and furnished with sharp recurved hooks.