W. Travers.—On the Origin in N.Z. of Polygonum aviculare, Z. 313 
by the whalers, or amongst those of the various plants which were brought 
down by the Greenwoods and others mentioned. 
With regard to the silence of D’Urville, Fraser, Allan Cunningham, and 
Lesson, it must be remembered that all these observers saw the extensive 
cultivations of the missionaries at the Bay of Islands and elsewhere, and if 
they did notice Polygonum aviculare at all, they would probably look upon it 
as having-been introduced amongst the other European seeds which they saw 
flourishing there. In this connection Mr. Kirk will probably call to mind the 
interesting description given by Darwin of the appearance of the mission 
station at Waimate, in 1836, and no doubt any English botanist collecting 
at that time in that district would at once have treated our plants as exotic. 
It must be remembered, moreover, that when Banks and Solander, and 
the Forsters, and Dr. Sparrman visited New Zealand, the cultivations of the 
natives were greatly more extensive than they are at present; and it is 
extremely improbable that neither in the numerous large tracts of cultivated 
land nor in the vicinity of the many extensive pas which they visited, nor 
along the many tracks which the natives then travelled, should specimens of a 
plant possessing the habits of Polygonum aviculare have been found, if it then 
existed -at all as part of the indigenous flora of the islands. 
` No doubt many indigenous plants have increased with extraordinary 
rapidity of late years. I may instance for example the Chrysobactron hookeri, 
which has spread and is still spreading over thousands of acres of moist 
ground, on the higher part of the South Island pastoral country, owing to the 
removal by fire of a vegetation which does not renew itself after fire —such 
as the sub-alpine species of Dracophyllum, Discaria, and Veronica—which in 
mingled growth usually cover the terraces and mountain sides in such valleys 
as those of the Acheron, the Clarence, the Upper Waiau, etc., in the Nelson 
province. : : 
Even more remarkable is the extraordinary spread of Triticum scabrum 
(blue-grass of the settlers) which over hundreds of thousands of acres of the 
same class of country is gradually displacing the native grasses that first 
follow the destruction of the sub-alpine growth. 
But none of these cases can be said to be strictly analogous to that of the 
Polygonum. In regard to each of the former certain checks have been 
removed, and the plant is profiting by such removal. In the latter the plant 
is always associated with the immediate occupation of land by man, making 
its habitation either in places which he has disturbed and then suffered to lie 
waste, or along the sides of the tracks which he makes over virgin country. 
The spread of the Polygonum is more analogous to that of the plant 
commonly termed the Maori cabbage. In every part of the South Island in 
which we find any traces of native occupation or travel, even high amongst 
pi 
