372 PLANTS OF NEW ZEALAND 



they cannot be discussed further here. They are mentioned 

 merely for the sake of pointing out that 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 habitat, the fact 

 that representatives of a single genus like Veronica can be 

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

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

 found in a single locality, all combine to afford the New 

 Zealand student of plant ecology, a field for investigation 

 perhaps unsurpassed within the same area, in any other part 

 of the Globe. 



WHIP-CORD VERONICAS. 



For our present purposes, we may roughly 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 stem ; (3) shrubs with toothed, generally fleshy leaves ; 

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

 stems. The second of these divisions only, will require 

 consideration here. This includes the remarkable species often 

 spoken of as the whip-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 has also been termed 

 the " mimetic " series. Some resemble a cypress so closely 

 as to deceive any but the expert botanist ; others mimic 

 the tamarisk, and another might well be taken for a lycopod. 

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

 amongst our flowering plants. Various endeavours have 

 been made to explain their extraordinary appearance, an 

 appearance, however, that is largely shared by certain species 



