10.] CHAPTER II. SPECIAL MORPHOLOGY OF THE MEMBERS. 43 



bearing foliage-leaves and flowers arise, as in Herb Paris. More commonly the 

 growth in length is limited, in which case the apex grows out into an aerial 

 annual shoot, whilst from the axil of a leaf at its base one or more subterranean 

 shoots are produced which carry on by innovation the elongation of the rhizome. 

 If the older portions of the rhizome persist for a long time, the basal portions 

 of the annual shoots together form a sympodium (Fig. 23 B) ; if, however, they 

 soon perish, then each annual shoot appears to constitute a distinct individual 

 (e.g. Ranunculus acris, Neottia). It is by the simultaneous formation of a number 

 of short innovation-shoots that the tufts of Grasses and Sedges are produced. 

 The innovation- shoots commonly develope roots of their own, but they may 

 remain con- 

 nected with the 

 main root of 

 the plant as in 

 Anemone Pulsa- 

 tilla. 



In rare cases 

 ( Hap I o mitr i it m 

 Hookcri and 

 some other foli- 

 ose Hepaticae ; 

 Psilotum among 

 Vascular Cryp- 

 togams), the 

 functions of 

 roots are per- 

 formed by sub- 

 terraneaii 

 shoots ; these 

 shoots are more 

 slender than 

 the subaerial 

 shoots, and 

 bear the merest 

 rudiments of 

 leaves. 



Shoots which 

 are unable to 

 grow erect by 

 themselves ob- 

 tain, in some 

 cases, the ad- 

 vantages of that position by climbing. The structure of the shoot may be 

 modified so as to subserve climbing. Branches are in some cases (Uncaria) 

 developed in the form of hooks, and may or may not bear leases ; these hooks 

 serve to attach the plant to others. In other cases, branches bearing small scaly 

 leaves are developed into tendrils, which twine round supports. In other cases 

 the whole shoot twines round a support (Fig 24 A B). 



FIG 24. A Part of the shoot of the Vine (\ rat. size) with two ten- 

 drils rr ; the upper one hears small leaves li and tranches ; the lower 

 one has become attached to a support x and has rolled up spirally; bb 

 petioles ; in this case the tendrils are branches which are pecu- 

 liar in that they are opposite to the leaves. B Twining shoot of 

 Ipomoea s, with leaves b and a bud 7; ; xx is the support. 



