42 



THE BOTANICAL MAGAZINE. 



[Vol. XXV. No. -289. 



Associated with these, there are : — Linmanthemum nywphoides 

 Link. var. japonica Miq., Hydrillaa siatica Mio., Utricularia 

 vulgaris L., Trapella sinensis Oi.iy., and the same submerged 

 hydrophytes as in the preceding zone. 



A remarkable fact in this zone is that the large patches 

 (1— 2m in diameter) of Zizania aquatica are floating freely, which 

 country men call '* Ukishima " (=floating islets). 



Fig. 4. 

 Luxuriant growth of Typhi angislifolia among tlie dense growth of 

 Ziz'una aquatica. 



(In tlie foreground we see the characterbtlc flowers of Typha.) 



On account of a tangled growth of marsh plants it is very 

 hard for boating through this zone. In this zone the move- 

 ment of water is very feeble so that oxidation of plant relics can 

 not go on sufiiciently^^ and produces gases of a very unpleasant 

 smell. Thus a deep accumulation of humus soil is produced at 

 its bottom. I should think that a luxuriant vegetation of 



]) Warming I.e. p. 63. 



