Pilularia or pillworts is a genus of unusual ferns of family Marsileaceae distributed in North Temperate regions, Ethiopian mountains, and the southern hemisphere in Australia, New Zealand, and western South America.

Depending on the taxonomic revisor, the genus contains between 3 and 6 species of small plants with thread-like leaves, and creeping rhizomes. The sporangia are borne in spherical sporocarpss ("pills") which form in the axils of leaves. Pilularia minuta from SW Europe is one of the smallest of all ferns.

Phylogeny

Recent work from Pryer Lab accepted four species of Pilularia, with a fifth, P. novae-zealandiae, being conspecific with P. novae-hollandiae. In addition, another species, P. dracomontana, has been described from South Africa.

References

• UK Biodiversity Action Plan

• Preston, C.D. & Croft, J.M. (1997). Aquatic Plants in Britain and Ireland. Harley Books, pp.31–32.

External links

• Pilularia globulifera UK distribution