274 Transactions. — Botany. 



stagnation. Eapidly flowing screams are very rare, and, un- 

 fortunately, I have no notes regarding their plant-life. 



Swamps. 



The swamp formation occurs principally in the lowest por- 

 tions of the central and northern part of Chatham Island, in 

 the immediate vicinity of lakes, lagoons, or sluggish streams, 

 and is distinctly a transition, in some cases, between lake and 

 forest ; indeed, the line of tension may be often observed 

 where swamp and forest plants intermingle. The swamp at 

 the southern end of Lake Huro is easy to examine, and is 

 of especial interest, since it offers every transition from the 

 waters of the lake to the ordinary lowland forest. The vege- 

 tation of the swamp seems determined by the average depth 

 of the water which more or less covers its floor. Where the 

 water is deepest there is to all intents and purposes an ori- 

 ginal formation, for the ground is altogether too boggy to per- 

 mit the inroads of cattle ; but in all other parts the trampling 

 of cattle and horses has consolidated the ground more or less 

 and reduced its water-content, thus making it suitable for 

 other plants, both indigenous and introduced. The floor of the 

 swamp in its unchanged portions consists of black peaty mud, 

 upon which it would probably not be safe to walk. Every- 

 where are large pools of water, 50 cm., more or less, in depth ; 

 while in winter the whole floor of the swamp, I learn from 

 Mr. Cox, is under water. Here there are no shrubs of any 

 kind. The vegetation consists of the curious restiaceous plant 

 Leptocarpus simplex, a well-marked xerophyte, which in New 

 Zealand occurs in salt meadows and sand-dunes (12 2 , p. 119). 

 In this formation Leptocarpus often forms very large patches, 

 to the complete exclusion of every other plant. Growing near 

 but not mixed with the Leptocarpus is Carex secta* in great 

 quantities, its " trunk " composed in large part of dead rhi- 

 zomes and roots matted together, on the summit of which the 

 living plant, raised out of the water, can avoid excess of mois- 

 ture, sending its roots far down into the decayed and semi- 

 decayed " trunk." 



As the water of the swamp decreases in quantity the 

 ground becomes quite covered with vegetation and decaying 

 vegetable matter. There the floor is very uneven, with its 

 many mounds of peat and decaying vegetation separated from 

 one another by holes full of water. In such a part of the 

 swamp Coprosma propinqua is very abundant, making a sub- 



* Pastor G. Kiikenthal, who is preparing an account of the genera 

 Carex and Uncinia for "Das Pflanzenreich," informs me that he con- 

 siders C. secta distinct from the European C. paniculata, to which 

 Cheeseman had previously referred it as a variety (8). 



