260 Transactions. — Botany. 



very great success, and now, where but three or four years 

 ago was a desert of sand, tall grass may be seen waving in 

 the breeze, each clump so close to the next that no sand is. 

 visible. Nor need a grass little relished by stock be alone 

 made use of. Elymus arenarvus has also been planted, and 

 thrives equally well, and Mr. J. Barker tells me that at 

 Kaingaroa stock eat it with avidity. :;: Although the sand- 

 dune vegetation has been much changed by the advent of 

 domestic animals, it is possible to get a fairly good idea of 

 what it was like in its original state by examining, in as 

 many localities as possible, those portions which have been 

 the least changed. The dunes abutting on that part of the 

 Wharekauri Beach the plant-covering of which has been 

 described above are well adapted for the purpose in view, 

 insomuch as they are still covered with vegetation almost to 

 high-water mark, the forest forming a wide belt, separated 

 from the sea-shore by a narrow zone, only a few inches in 

 width, of stable dunes covered with certain characteristic 

 sand-dune plants of more lowly growth. And this locality 

 also affords a striking example of the different stages in the 

 evolution of the vegetation of a sandy coast, commencing 

 with the more or less open vegetation of the strand, and pass- 

 ing by way of low dunes fixed by various sand-binding plants 

 to the final higher dunes covered with forest. 



Commencing at the junction of shore and dune, the sand 

 at first forms merely low mounds or ridges. The vegetation, 

 though fairly abundant for a medium such as sand, is open, 

 many places being quite bare. On the ridges grows the 

 common New Zealand grass Festuca littoralis. This gra^s 

 casts its " seeds"! in large masses alongside the parent plant, 

 where, being soon buried by the drifting sand, they readily 

 germinate. Behind the Festuca are higher mounds clothed 

 with Pimelea arenaria, the long cord-like underground stems 

 of which put forth adventitious roots near their extremities, 

 which latter, bending upwards, raise themselves above the 

 encroaching sand. The leaves are closely imbricating near 

 the extremities of the branches, but below are a little more 

 open. They are all most densely silky on the under-sur- 

 face, a most efficient protection against excessive transpira- 

 tion. Owing to the leafy extremities of the stems being erect, 



* Other plants used fcr binding sand with success in Europe are 

 Ammophila baltica, Calamagrostis epigea, Carex arenaria, and with 

 these are used various species of Pinus, Picea, Betula, and Abuts. 

 (See " Handbuch des deut&chen Dunenbaues," P. Gerhardt, Berlin, 

 1900.) 



f For the sake of conveniencp, the term " seed" is used throughout 

 this paper in its popular acceptation, and includes, of course, various 

 kinds of fruits. 



