''Mayaca fluviatilis'', also known as bog moss, is a perennial herbaceous submerged plant in the monogeneric family Mayacaceae. It is native to Central and South America, the Caribbean, and the United States where it is often sold as an aquarium plant. Through the aquatic plant trade, it has recently become naturalized in Sri Lanka, Singapore, and China. It has been identified in three locations in Australia ( Innisfail and Mossman in Queensland and Taree in New South Wales) but more populations are likely in other parts of Australia as well.

Description

The species was first described by the French botanist Jean Baptiste Christophore Fusée Aublet as ''La mayaque des rivieres'' in a tributary of the Sinnamary river in

Guyana Guyana ( or ), officially the Cooperative Republic of Guyana, is a country on the northern mainland of South America. Guyana is an indigenous word which means "Land of Many Waters". The capital city is Georgetown. Guyana is bordered by the ...

. ''Mayaca fluviatilis'' has soft thin leaves arranged in spirals on white or pale green stems which frequently grow up to one meter in length. Flowers grow on single stalks, 2 to 5 cm long, and are roughly 1 cm in diameter. The flowers of ''Mayaca fluviatilis'', like those of other Mayaca species, are lateral, heterochlamydeous (dissimilar

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

and petals in the whorls of the perianth), and isostemonous (has an equal number of stamens and petals). As a submerged plant, it is capable of growing in wet soil during the dry seasons. When submerged, it superficially resembles ''

Hydrilla verticillata ''Hydrilla'' (waterthyme) is a genus of aquatic plant, usually treated as containing just one species, ''Hydrilla verticillata'', though some botanists divide it into several species. It is native to the cool and warm waters of the Old World in ...

'', a native aquatic plant of Sri Lanka.

As an invasive species

Seeds are dispersed through the water, although specimens sold as aquarium plants are purported to be sterile. Stem fragments as small as 2 cm are capable of re-establishing new plants. When growing submerged ''Mayaca fluviatilis'' can form semi-floating mats in water up to 2 meters deep or as a semi-terrestrial plant in quasi-aquatic environments such as wetlands. Uncontrolled, these mats can block drains and irrigation channels, among other consequences. If the mats break free during flooding they are a risk to moored boats as well as bridges. There is also concern of ''Mayaca fluviatilis'' in Sri Lanka outcompeting endemic plants in already threatened habitats. ''Hydrilla verticillata'' has been shown to outcompete ''Mayaca fluviatilis'' in experimental settings and may be useful as a way of controlling invasive growth.

References

{{Taxonbar, from=Q15512691 Flora of South America Flora of North America Invasive plant species in Sri Lanka Invasive plant species in Australia Plants described in 1775 Poales