Vegetation (Floating River Vegetation) - Office of Public Works

Aquatic moss, Fontinalis antipyretica
•Dark green moss growth completely submerged.
•Circular domed moss shape.
•Found in shallow slow flowing water.
•Grows on gravel riverbeds or attached to submerged aggregate material.
•Can tolerate shade but requires sunlight to penetrate the water surface.
An overview of ecological characteristics associated with floating river vegetation recorded
or sighted in Ireland has been compiled in Table 34. The similarity between plant spp. illustrates the
similarity in leaf structure and habitat requirements. Although a probable identification can be made
based on leaf, seed capsule and habitat an absolute identification requires a flower head. This was
particularly evident with Ranunculus spp. in the absence of flowering structures during the course
of the survey (section 3.2).
3.4 Life cycle of floating river vegetation
To minimise the impact of channel maintenance on floating river vegetation it is essential
that plant reproduction and colonisation be understood. By focusing on plant regeneration the
nature and level of maintenance work required, the timing of the works and the appropriate
environmental drainage maintenance systems can be selected to provide favourable habitats for
floating river vegetation post maintenance works.
Essentially two forms of reproduction can be used by plants, firstly seed production and
secondly vegetative growth (Fig.16). Seed production is the preferred option for species survival
and genetic diversity since it is the result of pollination by two different plants and is referred to as
sexual reproduction. Asexual reproduction is the cloning of the mother plant by the production of
spare roots from a growing section of the plant vegetation. The new root section breaks from the
mother plant and develops as a new plant possessing the same genetic make-up as the initial plant.
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