312 Transactions. 



Rotonia district, have not been observed on any portion of the north-west 

 or northern faces. They are large-seeded plants, although some have fleshy 

 fruits, and are no doubt distributed by large birds. One of the two 

 naturalized rosaceous species may possibly have been spread by wild horses, 

 which are said to fatten on the fruits. 



The Northern Face. 



From the sand-crater which separates the northernmost peak (Wahanga) 

 from the middle peak (Euawahia) after a few hundred feet of steep scoria 

 descends a beautifully easy slope of scoria down to the lake-edge. This 

 slope is comparatively bare of continuous scrub growth until near the 

 40 ft. terrace above the lake, when a shrubbery of Leptospernmm, &c., is 

 encountered. This slope, where it descends without a break, foims a 

 natural boundary separating what may be called the north-western area 

 from the northern area. The area north of this boundary has been visited 

 on two occasions. Numerous dry vertically walled ravines about 40 ft. deep 

 run roughly parallel to each other, making progress across country slow. 

 Landing near the eucalypts at the north end of the lake, several aquatic 

 and semi-aquatic plants were noticed. In small stagnant pools was the 

 submerged Nitella (two species), Potamogeton Cheesemanii, and Myrio- 

 phyllum sp. ; while on the margins were Glossostigma elatinoides (with 

 pinkish flowers) and Typha angustifolia var. 



Progress on to the 40 ft. terrace (the lake rose 40 ft. at the time of the 

 eruption and afterwards subsided ; this may be the beach formed at that 

 time) was made easy by the tracks of wild horses. Several naturalized 

 plants were noticed — e.g., Rumex crispus, Oenothera (in beautiful yellow 

 flower), Anagallis arvensis, Rumex Acetosella, Carduus pycnocephalus, Sonchus 

 arvensis, Erigeron canadensis, Verhascum Blattaria, Bartsia viscosa, and, what 

 is lamentable, Rosa rubiginosa and Rubus fruticosus. There is no doubt if 

 these latter two get thoroughly established on the mountain they will be 

 a fearful curse in days to come. The Oenothera seems to be able to thrive 

 on the bare scoria without the aid of any humus, and is rapidly travelling 

 up the mountain. A most interesting fact is that the great Coriaria asso- 

 ciation is here dying out. The tree form of Coriaria ruscifolia, 15 ft. high, 

 with many large trunks springing from one root, as described above, are 

 now dead. This accords with an observation of Mr. C. Way, of the Wairoa 

 accommodation-house, that, although the Coriaria is the first shrub to take 

 possession of volcanic ejectamenta, it is comparatively short-lived. Here, 

 where it is obviously dying out from old age, it is giving place to vigorous 

 thickets of Aristotelia racemosa and Fuchsia excorticata. Aristotelia is 

 entirely dominant in places, and is 20-25 ft. high ; but associated with it are 

 Solanum aviculare, Melicytus ramiflorus, Cyathodes acerosa, MuehlenbecMa 

 complexa, Asplenium flacciduni, and A. adiantoides. Some 50-60 ft. above 

 the lake the open scoria slope is reached, which leads to the sand-crater arete 

 of Tarawera. Here a most remarkable change is going on, which is vui- 

 folded to one as the gradual ascent is made. The gentle slope is covered in 

 places with uneven patches of Raoulia austrfdis and R. glabra. These are 

 the dominant patch plants. Others are Piinelea laevigata, MuehlenbecMa 

 axillaris, and even Leucopogon Fraseri. Olearia furfuracea, the dominant 

 composite shrub of the mountain, in full flower is a fine sight. Occasion- 

 ally, where the water-supply is favourable, lichens and moss may perform 

 their usual function of transforming the barren rock into fertile soil, but 

 the Raoulia must be accounted the great humus-maker of this mountain. 



