672 CLIMBING PLANTS. 



foliage in the following manner: — As a young shoot it grows first of all vertically 

 erect; it has as yet no lateral branches, and its leaves at the free-growing end are 

 still small, furled, and crowded closely together into a cone. These young turgescent 

 shoots readily pass through the forks of the boughs, even through narrow chinks 

 and meshes of the net- work of twigs and branches in the thickets, without suffering 

 injury. When its growth in length is terminated, the shoot unfolds its leaves and 

 sends out lateral branches which project at right angles in all directions. These 

 reflexed leaves and the lateral branches which have been produced above the gaps 

 in the matted undergrowth, now get a good purchase on the rough boughs of the 

 underwood; the slender upgrowing shoot is suspended by them as if by barbs, and 

 it is frequently also actually woven into the underwood. 



These forms of weaving stems may be distinguished according to the character 

 of the support. First, that of the hedge-forming shrubs, of which Lycium may 

 serve as type. It is astonishing how its long whip-like shoots, as they grow up 

 from the ground on the edge of a wood, find their way between the spar-like 

 branches of other growths, and then perhaps at the height of the lowest boughs 

 of the crown of one of the trees, the free end projects as if from an opening in a 

 roof. In the course of the summer the thin slender stem lignifies, and leafy 

 lateral shoots spring from the axils of the upper leaves at about a right angle. 

 These end in stiff spines. Meanwhile the highest portion of the shoot becomes 

 bent over some bough, so that the whole shoot is so interwoven with the under- 

 growth, that in attempting to extricate it we tear innumerable supporting branches 

 and twigs, and set the whole neighbourhood in motion. The lignified shoot of the 

 first year survives the winter; next spring those portions of it which rest horizon- 

 tally on the branches produce new shoots in pairs, close to the thorny lateral 

 branches. Of these one usually remains small; the other, slender and vigorous, 

 pushes up into the crown and repeats the method of growth of the former shoot. 

 As this is repeated from year to year the whole crown of the tree becomes densely 

 interwoven with the Lycium shoots. Often it happens that shoots are produced, 

 which hang down from the tree-crown like branches of a weeping-willow draping 

 the supporting tree as with a curtain, or forming an actual hedge in front of it. 



The following well-known plants develop in accordance with this Lycium 

 type: — Numerous roses (Rosa), brambles (Rubus), barberry (Berberis), spiraeas 

 (Spircea), sea-buckthorn (Hippophae), jessamine (Jasminum), Celastrus scandens, 

 and numerous other woody hedge-formers which grow preferably on the borders 

 of forests. Many roses, as, for example, the Rosa sempervirens, abundant in 

 the Mediterranean floral district, not only weave through the undergrowth, but 

 often reach the tops of the highest oaks. Also many brambles {Rubus) reach far 

 up into the boughs of the tree-crown, and then not unfrequently depend their long 

 shoots in arching curves. I measured the length of a stem, ^ centimetre thick in 

 the middle, of a species of bramble (Rubus amoenus) which had interwoven with 

 the tree-crown, and found it to be six and a half metres. The long whip-like shoots 

 of Jasminum nudiflorum and Celastrus scandens also reach the tops of high trees 



