Across the flood plain of the Manawatū and on the low-lying land bordering the river, the predominant vegetation was semi-swamp forest, mostly kahikatea and pukatea. Three major swamps bordered the Manawatū: Moutoa Swamp north of the river, towards the mouth, known as the "Great Swamp" in the 19th century; Makerua Swamp further inland, to the south of the Manawatū and north of the Tokomaru River, which covered 22000 acres; and Taonui Swamp on the north side of the river. The main vegetation in the swamps was harakeke and raupō: harakeke in the drier parts, raupō in the wetter.