FLORA
> Pilularia minuta
Family: Marsileaceae
A flowerless plant, whose reproduction is made by spores instead of seeds, like the plants of genus Isoetes and other genus of ferns.
The spores are found within round receptacles (sporangia), covered in brown hair and located at the base of the leaves.
Roots and leaves emerge from the long rhizomes (underground stems). The leaves are very thin and long.
This plant is difficult to observe due to the small and slim leaves, which are only 2 to 4cm long.
Photo of Carla Pinto Cruz
It is found in temporary ponds, in pools along dirt roads, and on the edges of ditches.
Pilularia minuta is a steno-Mediterranean plant. It is found in France, in the regions of Hérault and Alpes-Maritimes as well as in Corsica in Bonifacio, Lecci, and in the vicinity of Aleria and Ghisonnaccia. In Portugal, it is present in the Algarve, and in Spain, in the regions of Andalusia, Castilla y Leon, and Menorca (Anthos 2009). In Italy, it occurs in the region of Rome, Sardinia and Sicily. It has been found in Greece, in the west and northern islands of the Aegean Sea, as well as in Cyprus.In Croatia, it is present at the Dalmatian coast. Turkey has a subpopulation close to Izmir. In Morocco, it occurs southeast of Tiflet, west of Benslimane, and in Rommani.
It is probably extinct in Algeria, but there are old records from Kabylie, Castiglione-Bou Ismaïl, Djebel Santo, Mudjardjo, Les Issers, Msabia. In Tunisia, it has been discovered lately in 2006 in Garâa Sejenane.
In the Mediterranean region, the extent of occurrence of P. minuta is about 2,300,000 km² within which the occupied area is very small, but nevertheless exceeds 10 km² when measured using a 1 km² grid.
Rhazi, L., Grillas, P. & Rhazi, M. 2010. Pilularia minuta. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 24 August 2015.
In Portugal is very rare.
In spite of its large distribution along the Mediterranean basin, the number of sites as well as the real area occupied by Pilularia minuta remains very small resulting from the scattered distribution and the small size of the temporary ponds.
The population sizes at all sites are very variable from one year to the next according to rainfall conditions. This makes the assessment of the status of the populations difficult, however they seem to be globally in decline following the destruction of the sites (ponds of Biot in France destroyed in 1975, ponds close to Alger destroyed by urbanization and agriculture).
At the remaining sites, the populations are vulnerable and threatened notably by the increasing pressure from anthropogenic activities, especially in North Africa. The populations are classed as being severely fragmented.
It is considered as vulnerable in Italy, Greece, France and Spain, Endangered in the Balearic Islands and very rare in Morocco, Algeria and Tunisia.
It is considered a rare species, classified as Threatened in the Red List of the International Union for Conservation of Nature and Natural Resources (IUCN). It is protected by the Bern Convention, and listed in the Spanish Red List.
Rhazi, L., Grillas, P. & Rhazi, M. 2010. Pilularia minuta. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 24 August 2015.
