546 Transactions. 
Art. 37.—On the Behaviour of certain New Zealand Arboreal Plants 
when gradually buried by Rwer-shingle. 
By C. E. Curistensen, Head Masseur, Tourist Department, Rotorua. 
[Read before the Philosophical Institute of Canterbury, 3rd December, 1919 ; received by 
Editor, 21st December, 1921 ; issued separately, 22nd May, 1923.] 
Plates 51—53. 
INTRODUCTION. 
Tue River Perceval rises on the southern slopes of the Mount Perceval — — 
Range, flows through a rather narrow valley bounded by high tussock- _ 
covered hills, and finally, after a course of about five miles, emerges on the — 
Hanmer Plains. At a certain point the river for a num mber of years has 
been raising its bed, and during this period has invaded the neighbouring 
plant-associations. 
No literature relating to the burial of woody plants by river-shingle 
has. come to my notice, but there is an abundant literature nee 
sand on the one hand and sphagnum moss on the 
Though neither of these kinds of burial is identical with that of shingle, 
yet evidently there is a close connection between them. This is ealt 
with when considering the physiological relation of the buried shrubs to 
their new environment. 
The observations on sand-dune plants were made at the mouth of the | 
Waimakariri River, Canterbury, the sphagnum-moss plants at. the top 
Jack’s Pass, Hanmer Springs, and the greg tenn plants in the upper 
үп of the Perceval River bed, Hanmer Sprin 
I should here like to record my thanks to Dr. L Cockayne, F.R.S., for 
assistance given me in preparing this paper. 
SAND-DUNE PLANTS. 
Coprosma acerosa A. Cunn. (the sand-coprosma) and Pimelea a arenam. аи 
A. ees (the sand-pimelea), both low- -growing shrubs, can tolerate фиш aui 
by sand, and with a slow drift can continue to grow upwards, owingío с 
the power of putting forth adventitious roots from the uppermost branches. 
Cassinia fulvida Hook. f. develops numerous rootlets when its branches 
are covered with sand. ў 
Leptospermum scoparium Forst. also has the Pieds s^ put i imm 
adventitious roots where buried by the driftin ms to be 
oe tas the worse when the sand has shifted and n dem méme, ida have _ 
wi 
байг alba Linn. (the common willow) and Sambucus nigra Linn. 
common elderberry), where covered with drifting sand, ma "forth roots 
from trunk and dul One дөбөтү: 15 ft. in heights had a number 
of these adventitious roots partially uncovered, some of them being many - 
feet in length and up to 4in. in diameter. The ends of these roots being 
buried in the sand enabled them to continue their functions, and m 
few instances branches were growing from the larger roots. 
