''Pilularia'' or pillworts is a genus of unusual
fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...
s of family
Marsileaceae
Marsileaceae () is a small family of heterosporous aquatic and semi-aquatic ferns, though at first sight they do not physically resemble other ferns. The group is commonly known as the "pepperwort family" or as the "water-clover family" because ...
distributed in North Temperate regions,
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
n mountains, and the southern hemisphere in
Australia,
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, and western
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
.
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
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cyc ...
are borne in spherical
sporocarps ("pills") which form in the
axils of leaves. ''
Pilularia minuta'' from SW Europe is one of the smallest of all ferns.
List of species
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
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
.
* ''
Pilularia americana''
A.Braun (American pillwort)
* ''
Pilularia globulifera''
L. (pillwort)
* ''
Pilularia minuta''
Durieu (least pillwort)
* ''
Pilularia novae-hollandiae''
A.Braun (austral pillwort)
* ''
Pilularia dracomontana
''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 taxono ...
''
N. R. Crouch & J. Wesley-Smith (Dragon-Mountain pillwort)
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
Salviniales
Fern genera
{{Polypodiidae-stub