87'2 PLANTS OF NEW ZEALAND 



they cannot be discussed further here. They are mentioned 

 merely for the sake of pointing out tliat the students of the 

 New Zealand Flora have opportunities, such as are granted to 

 few, of studying such questions. The great variety of 

 environment to be found in the islands, the extreme 

 sensitiveness of many species to change of liabitat, the fact 

 that representatives of a single genus like Veronica can be 

 found at all altitudes from tire sea-shore to snow-line, tire 

 wonderful variety of forms, in this and other genera, to be 

 found m a single locality, all conrbine to afford the New 

 Zealand student of plant ecology, a field for investigation 

 perhaps unsurpassed within the sanre area, in any other part 

 of the Globe. 



Whip-coed Veronicas. 



For our present purposes, we may rouglily divide the New 

 Zealand Veronicas into four sections. (1) Shrubs with 

 normally expanded entire leaves ; ('2) shrubs with minute 

 scale-like leaves, often imbricating, and closely appressed to 

 the stenr ; (3) shrubs with toothed, generally fleshy leaves ; 

 (4) herbs or semi-herbaceous plants witli creeping slender 

 stems. The second of these divisions only, will require 

 consideration here. This includes the remarkable species often 

 spoken of as the wlrip-cord veronicas, on account of the close 

 resemblance of their stems to a piece of green whip-cord, or 

 the plaited thong of a whip-lash. It Iras also been termed 

 the " mimetic " series. Some resemble a cypress so cl<:)sely 

 as to deceive any but tlie expert botanist ; others mimic 

 the tainai-isk, and another might well be taken for a lyc()pod. 

 There are few, if any, more remarkable forms than these 

 amongst our flowering plants. Various endeavours have 

 l)een made to explain their extraordinary appearance, — an 

 appearance, however, that is largely shared by certain species 



