A checklist of rheophytes of Cameroon

Abstract

Rivers in Cameroon were surveyed to collect and document rheophytic plants. Rheophytes are the dominant aquatic macrophytes in tropical river systems, where they are adapted to extreme environments of rushing water (e.g., river rapids, waterfalls and flash floods). Rheophytic plants are useful indicators of river health. However, their habitats are threatened by human activities such as agriculture, plantation development, alluvial mining and dam construction, particularly in tropical countries. In this survey we documented 66 rheophytic species in 29 genera and 16 families. Two ferns, 8 monocotyledons and 56 dicotyledons were listed. Apart from the Podostemaceae family in which all species are rheophytic, the other 15 families have few species which are rheophytic. Five of these families have up to four species and the remaining 10 have only one member as a rheophytic species. The conservation status of each species is assessed and discussed. This work urges botanists, conservationists, and policy makers to do more to protect the habitats of rheophytes and put in place strategies and action plans for the conservation of this important biological group.

Taxonomic Monograph ofSaxicolella(Podostemaceae), African waterfall plants highly threatened by Hydro-Electric projects, with five new species

“…More recently intensive surveys dedicated to finding sites for this family in Cameroon have been carried out above all by Ghogue, but also by dedicated Podostemaceae researchers from Switzerland, Ghana, USA, Japan and Britain but no further locations for Saxicolella nana have come to light. Kuetegue et al (2019) studying the rheophytes of Cameroon concluded that it should be assessed as Endangered ENB2ab (ii, iii), with no additional data. Much of the length of the Nyong S of Yaoundé is not suitable for Podostemaceae due to the absence of rapids.…”

“…The Red Data Book of Cameroon Plants (Onana & Cheek 2011: 253) reassess the species as EN B2ab(iii) since two locations (above) are recorded. Kuetegue et al (2019) Taylor (1953: 57) stated: "Amongst African genera the plant is most closely related to Saxicolella and Pohliella, in each of which the flowers is unistaminate and erect within the spathella, but it differs from these genera in having entire rosulate leaves, much more shortly pedicellate flowers and complanate stigmas". At that time both genera were only known from their type species and their circumscription was incompletely known.…”

“…(2011: 252 -253) assessed the species as EN B2ab(iii) Kuetegue et al (2019). also assess the species as EN B2ab(iii) citing no new data Cusset (1987).…”

Occurrence and nutrient retention of aquatic macrophytes in roadside streams in the Mount Cameroon region

“…Aquatic macrophytes include both vascular and non-vascular plants which could be floating, submerged or emerged in shallow waters and influence the physical, chemical and biological environment [5]. Macrophytes generally colonize shallow ecosystems such as streams, rivers, lakes, ponds, marine environments, and even rapids and falls as in the case of Podostemaceae [6] and constitute important ecological engineers which influence ecological processes (e.g., nutrient cycling, habitat, and food provision to fishes and zooplankton, water purification and ecological attributes of other biotic aquatic attached assemblages like species diversity and composition). Owing to their high rate of biomass production, macrophytes have primarily been characterized as an important food resource for aquatic organisms, providing both living (grazing food webs) and dead organic matter (detritivorous food webs) [7].…”

“…A hand full of studies have been documented on aquatic macrophytes in Cameroon, ranging from the identification of endemic aquatic taxa like Podostemaceae in rivers and rapids in the different regions of Cameroon [6], the role of aquatic plants in nutrient and heavy metallic uptake in both lotic and lentic ecosystems [14] [15] and their role in phytoremediation [16] [17] [18].…”