Bi^iD.—Lianes of the Ancient Forest of Caiiterbiir// Plains. 315 



Art. XXXII. — -Observations on the Lianes of the Ancient Forest of the 



Canterbury Plains of New Zealand. 



By J. W. Bird, M.A. 



[Bead before the Philosophical Insfikite of Canterbury, 3rd November, 1915.] 



Plates XXIII-XXVI. 



I. INTRODUCTION. 



Lianes form, in the New Zealand forest, an ecological group of prime 

 physiognomic importance, as pointed out by L. Cockayne (1908, p. 24). 

 Further, within quite limited areas the various life-forms of this class 

 of plants occur side by side, so that it is comparatively easy to study and 

 compare their forms, adaptations, behaviour, and life-histories. Up to the 

 present time such studies have been for the most part neglected ; nor 

 is this to be wondered at, since in a newly settled country the earliest 

 botanical investigations must of necessity be floristical, while even in the 

 Old World ecology is yet in its infancy. The work of L. Cockayne stands 

 out as a notable exception to the above statement, for in a series of writings, 

 commencing in 1898 and extending to 1915, he has given a good many details 

 as to the methods of climbing and life-histories of lianes, and the evolution 

 of the climbing habit ; but he has not published any comprehensive account 

 of the group. Nor in this paper is it possible for the writer to attempt 

 anything really comprehensive — a matter that would have required several 

 years' experience in the field in all parts of the botanical region. On the 

 contrary, the study, for which no completeness is claimed, since New Zea- 

 land contains no less than forty-seven lianes, which belong to sixteen families 

 and twenty-two genera, is confined to one definite forest area, Riccarton 

 Bush, the last remnant of the ancient forest of the Canterbury Plains.* 



Nor is the study of the lianes in this area complete. A complete account 

 must of necessity include stem-anatomy. This in itself is of such import- 

 ance that it should be made the subject of a separate paper, for thus only 

 can it receive its deserved attention. There are experiments to be made 

 dealing with water-conduction, mechanical principles, &c., and for this 

 considerable time and observation are necessary. Moreover, the forest in- 

 vestigated is of such importance that it is rightly preserved closely ; and 

 the amount of material required for a complete stem account cannot be 

 obtained without considerable destruction to the forest. 



Riccarton Bush is a portion of an ancient kahikatea {Podocarpus dacry- 

 dioides) forest. The members of this species do not here grow very closely 

 together, but they attain a great size, their trunks, often 1-6 m. in diameter, 

 rising straight up to a height of 30-40 m., with their lowest branches 20 m. 

 from the ground. On the surface of the ground their roots spread widely, 

 many of them twisting up and forming knees about 50 cm. in height, and 

 others, through the displacement of the soil by which they were formerly 

 partially covered, forming a kind of reticulate platform round the base of 

 the tree (Plate XXIV, fig. 2). Growing to the same level in the forest, 

 but present in small numbers, are two other species of Podocarpus — P. 

 spicatus (matai) and P. totara (totara) — and two species of Elaeocarpus — 

 E. dentatus and E. Hookerianus. 



* For an account of this association see Armstrong, J. F.. 1369, and Cockayne, L.,. 

 1914. 



