Low and medium altitude marshes are located at altitudes of 775 to 1,700 m above sea level. It was found that in Burundi there are no peatlands below 1,400 m. Cyperus papyrus swamps dominate other types of swamps in these areas. They are located in the Rusizi plain, in the central plateau, in the Kumoso depression and at the level of the northern lakes. Everywhere, this species prefers a constantly waterlogged environment and forms a continuous monospecific layer.

From time to time, some shrubby and suffrutescent species are scattered in vast floating meadows of Cyperus papyrus such as: Dissotis throthae, Rubus apetalus, Aeschynomene schimperi, etc. The same stratum can also shelter Phoenix reclinata, characteristic of swampy forests sometimes contiguous with Cyperus marshes, where the body of water varies. according to the seasons. The herbaceous stratum includes species such as Cyperus latifolius, Polygonum strigosum, Polygonum pulchrum, Spermacoce princeae, Cyperus distans, Dryopteris gonglyloides, etc. Cyperus papyrus marshes, drained and cultivated, then finally abandoned, are first invaded by fallow land composed almost exclusively of rueral and post-cultural plants, and by Cyperus latifolius which then settles there.

At the Rusizi delta, there is a 500 ha swamp including:

- Typha domingensis vegetation, clearly dominant in the Gatumba marsh. Apart from Typha domingensis, this vegetation also includes Cyperus dives, Sesbania sesban, Phragmites mauritianus and Cyperus papyrus; - Phragmites and Vossia cuspidata vegetation, temporarily wet soils at the northern limit of Lake Tanganyika;
- Vegetation with Panicum repens and Cyperus laevigatus where each species forms a monospecific stand; - Vegetation floodplain at

Sporobolus spicatus.