152 NEW ZEALAND PLANTS. 
When the flax is established nature does not let it have all its 
own way. ‘The law of plant-succession at once comes into opera- 
tion. Various shrubs, their seeds already in the ground or brought 
by wind or birds, quickly put in an appearance—e.g., a divaricat- 
ing small tree (a variety of Olearia virgata), the common karamu 
(Coprosma robusta), the common koromiko (a variety of Veronica 
salicifolia), and other swamp-shrubs. Nor must the cabbage-tree 
(Cordyline australis) or the toetoe-grass (Arundo conspicua) be omitted. 
Also very aggressive are certain lianes, especially the swamp-lawyer 
(Rubus schmidelioides) and the bell-vine (Calystegia sepium). Did not 
the flax-miller wage constant war on these robbers of his “‘ swamp ” 
his profits would decrease year by year. 
There are many other indigenous induced plant - associations. 
Here, briefly, are a few of them: Fern-heath of bracken (Péieridiwm 
esculentum)—this plant is undoubtedly, though indigenous, the prince 
of ‘ noxious weeds” so far as New Zealand goes; manuka thicket— 
the manuka is nearly as aggressive as bracken; tauhinu (Cassima 
leptophylla) shrubland—the tauhinu is another potent weed, neces- 
sitating each plant to be pulled up by hand; wineberry (Avistoteha 
racemosa) thicket—this replacing certain classes of forest after burn- 
ing, or even felling; colonies of the swampz-lilies (Chrysobactron 
Hookerit and C. Rossii), thanks in part to their being summer-green 
herbs—the former species in the montane belt of the eastern Southern 
Alps after the tussock or the bog is burnt, and the latter species 
after burning the tussock-grassland of Campbell Island. 
Adventitious associations next claim attention. These are of 
various classes, according to whether they are composed of trees, 
shrubs, herbs, or water-plants; while each of these classes may be 
subdivided with regard to the origin and biological standing of such 
subdivisions. ; 
The most important adventitious tree-associations are those formed 
by the following : Gum-trees (Hucalyptus), Australian acacias (Acacia), 
willows (Salix), pines (Pinus radiata and P. Pinaster), and the locust- 
tree (Robina pseud-acacia). 
The following adventitious associations may also be mentioned : 
(1.) Those of leguminous shrubs—e.g., the gorse (Ulex europaeus), 
the broom (Cytisus scoparius), the Cape broom (Cytisus candi- 
cans), the tree-lupin (Lupinus arboreus). (2.) Those of rosaceous 
shrubs—e.g., the sweetbrier (Rosa rubiginosa), various kinds of black- 
