Luronium natans is native to the UK and is protected by UK and European law under
Annexes II and IV of the Habitats Directive, Appendix I of the Bern Convention,
Schedule 4 of the Conservation (Natural Habitats, etc.) Regulations 1994, and
Schedule 8 of the Wildlife and Countryside Act, 1981. It is also listed as UK priority
BAP species and the current distribution is restricted to less than 100 hectads in the
UK and it should therefore be classed as nationally scarce (Lockon 2014).
The main stronghold for the species is in the oligotrophic lakes of central Wales and
Cumbria, as well as some canals in Wales and Shropshire (Preston et al. 2002). Due
to its deep-water habit, L. natans is easily overlooked and although this may have
resulted in it being under-recorded in some locations, there is also evidence of it
having been lost from some lowland sites in recent years (Preston & Croft 1997).
In Llyn Padarn, Luronium natans was first recorded in 1848 (Kay et al. 1999), and
more recently is known to have been relatively common with records from at least 4
distinct locations reported by Andy Jones in 1997 (CCW Species & Monitoring Report
No. 98/02/11 - Luronium natans (floating water-plantain) at Llyn Padarn SSSI) (
Figure 1). Survey data since 1997 are less complete. The aquatic flora was surveyed
using Common Standard Monitoring methodology (JNCC 2005) for WFD assessment
(Goldsmith et al. 2005, 2010, 2013), but this method does not necessitate whole-site
assessment and L. natans was only recorded in one survey section at the south east
end of the lake (an extensive bed from 0.8 – 2.4 m water depth). The other survey
sections did not coincide with earlier L. natans records and therefore the extent of the
species within the lake since 1997 has not been verified
