158 - The Plant Formations. 
linearis grow in great abundance in a hot atmosphere always saturated with 
moisture'). 
Hot water swamps contain many ordinary swamps-plants, e. g.: Zypha, 
Scirpus lacustris, Elaeocharis sphacelata, Cladium articulatum, Carex ternaria, 
together with Dryopteris parasitica. The latter, according to KIRK, formerly 
covered acres of the swamp on either side of the warm river connecting lakes 
Rotomahana and Tarawera, “its dull green fronds sometimes five feet high 
and seven inches across but in this state it is usually barren”. The same fern 
grew in abundance also on the “White Terrace”, covering “the thin crust 
overlying the scalding mud and from its erect, rigid habit and the strict sori- 
laden pinnules presenting a forcible contrast to the luxuriant swamp form”. 
On the shore of Lake Rotorua at Ohinemutu, growing on heated ground 
or where there is an excess of certain salts &c. in the soil, is Fzmöristylis 
dichotoma and the presence of the following coastal plants may perhaps be 
correlated with the edaphic conditions: Dromus arenarius, Scirpus maritimus, 
Carex pumila, Leptocarpus simplex, Funcus maritimus var. australiensis and 
Ranunculus acaulıs. 
Where the heat aseeiatien) comes into close proximity with steam of 
a certain character or on to soil containing salts &c., as mentioned above, the 
formation becomes open and by degrees the Ener: give out excepting 
Leptospermum ericoides and Styphelia fasciculata, but the former becomes an 
altogether prostrate, rooting plant, whereas the latter remains erect. Where 
steam charged with sulphur-fumes strikes, vegetation is absent. Round boiling- 
mud holes the shrubs are erect and luxuriant. ZLycopodium cernuum can tol- 
erate far more hot steam, heated soil and fumes than any other heath-plant. 
d. Shrub-swamp. 
Either through the presence of Carexr secta ”trunks“, the raising of the 
surface in places by gradual deposition of peat, or the occurrence of areas dry 
et affording positions where the seeds of shrubs can germinate, 
bs may gradually invade a swamp, and, in course of time, become the 
EaeR species. 
The dominant plant i is nearly always Ts ie scoparium, which may 
form a most close growth of straight, slender stems. Cordyline australis is very 
frequently an accompanying plant, and as already seen, when dealing with 
_ forest, it may make a pure, low-tree association. Other shrubs of the formation 
are: — Carmichaelia angustata (North-western district), C. gracilis (Eastern and 
North-Otago districts, but rare), C. paludosa (Western district), Coriariaruscifolia, 
Eugenia maire sen Island), ger crassifolium, Griselinia httoralis. 
1) For further Berksedan 160 H FETTE 11867: 402) and Kirk (18736: 336), nn the state 
ments as to all these “hot-water” ferns being confined to such a station is now kno 
follows that of ern: of rer &e. 
