60 NEW ZEALAND PLANTS. 



PROLONGED JUVENILE FORMS OF NEW ZEALAND PLANTS. 



If the seed of Veronica cupressoides, or of any one of the " whip- 

 cord veronicas," as they are aptly designated, be sown, it will quickly 

 germinate and produce a young plant, altogether distinct from its 

 parent. In the old plant the leaves are represented by green scales 

 pressed closely against the stem ; they are also thick, and have a 

 peculiar anatomical structure. In the seedling, on the contrary. 

 there are true leaves with a stalk and blade, which are quite thin and 

 of an anatomical structure absolutely different from that of the adult. 

 In other words, the juvenile and the adult plants might be two different 

 species, each adapted for a quite different mode of life, the adult for 

 an arid climate and the juvenile for a- moist forest region. 



If we are in a position to carry on our investigations a little 

 further, and to grow some of the seedlings in the open air and others 

 in a glass case so constructed as to always contain air saturated 

 with moisture, the plant in the open will by degrees assume, the adult 

 and dry-climate habit, while the other will remain in the juvenile 

 and wet-climate form, not for a week or two merely, but for years : 

 indeed, so long as it is kept in a " moist chamber " it will remain a 

 juvenile plant. 



And now for a third experiment. Take a rooted cutting ot an 

 adult piece of the veronica, and place it in the moist chamber. After 

 a few weeks its new growth will be of the juvenile form, and juvenile 

 and adult leaves will be on the plant at the same time (fig. 24). Similar 

 experiments with certain of the New Zealand brooms (CarmiGhaelia) 

 and with the wild-irishman (Discaria toumatou} will lead to a similar 

 result. To inquire into this matter at length would be out of place 

 here, but any general account of New Zealand plant-life would be 

 most incomplete without some reference to this extraordinary 

 phenomenon. A few analogous examples may throw a little light 

 on the subject. Many coprosmas and other shrubs belonging to 

 diverse families* have a curious habit of growth, which makes them 

 outwardly so similar that they are not easy to be distinguished when 



* The following are. some of these shrubs: The weeping-matipo ( 

 divaricaia), Pittosponnn rigidum, the mountain-currant (Arixfotvlia fruticosti). the 

 wauwaupaku (Nothopanax anonniJiini), various species of Hymenanlhcra, and 

 Melicytu* in icrantlms. 



