Marsilea batardae 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Polypodiopsida Salviniales Marsileaceae

Scientific Name: Marsilea batardae Launert
Common Name(s):
English Lusitanian Water Clover
Spanish Trébol de Cuatro Hojas
Marsilea aegyptiaca Willd. var. lusitanica Cout.
Marsilea strigosa Willd. subsp. lusitanica (Cout.) R.Fernandes
Taxonomic Source(s): Christenhusz, M. and Raab-Straube, E. von. 2013. Polypodiopsida. Euro+Med Plantbase - the information resource for Euro-Mediterranean plant diversity. (Accessed: 2015).
Taxonomic Notes: Marsilea batardae was recently distinguished from Marsilea strigosa, from which it differs in sporocarp size and form. All subpopulations in Portugal, previously attributed to Marsilea strigosa, belong to Marsilea batardae (Launert 1983).

Assessment Information [top]

Red List Category & Criteria: Endangered B2ab(ii,iii,iv,v) ver 3.1
Year Published: 2017
Date Assessed: 2016-05-31
Assessor(s): Christenhusz, M., Lansdown, R.V., Bento Elias, R., Dyer, R., Ivanenko, Y., Rouhan, G., Rumsey, F. & Väre, H.
Reviewer(s): García, M. & Troìa, A.
Contributor(s): Medina Domingo, L.
Marsilea batardae is an aquatic fern endemic to the Iberian Peninsula, where it has a small area of occupancy (AOO) of less than 500 km² and is subject to continuing declines in AOO, habitat quality, number of subpopulations and number of mature individuals. It is found on around 25 sites and the population is considered to be severely fragmented due to changes in land management and the fluvial habitat it inhabits. The main threats are the general destruction and degradation of standing water bodies, the modifications of hydrological networks such as the construction of dams, the canalisation of streams, the degradation of water quality and alteration of ancient grazing practices. The species is therefore assessed as Endangered.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Marsilea batardae is endemic to the Iberian Peninsula, where it is limited to the southwestern quarter, mainly in the hydrological basins of the rivers Tejo, Sado, Guadiana and Guadalquivir. In Portugal, it occurs in the Alentejo region (Alqueva dam) and São Miguel do Pinheiro region, east of the Parque Natural do Vale do Guadania. In Spain it is found in the southwestern provinces of Badajoz, Ciudad Real, Huelva, Cáceres and Córdoba (Bañares et al. 2004). Its presence is uncertain in the provinces of Toledo and Valencia (Rosselló-Graell et al. 2000). The area of occupancy (AOO) is estimated to be smaller than 500 km².
Countries occurrence:
Portugal (Portugal (mainland)); Spain (Spain (mainland))
Additional data:
Estimated area of occupancy (AOO) - km2:100-500Continuing decline in area of occupancy (AOO):Yes
Estimated extent of occurrence (EOO) - km2:161150
Upper elevation limit (metres):300
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Marsilea batardae has a scattered distribution and the number of localities is about 25. In Portugal, the number of individuals, although not precisely estimated, may be considered to be low (ICN 2006). About five locations have disappeared due to the construction of the Alqueva reservoir in Portugal, but around seven new subpopulations have been found in Spain since 2004, especially in the area of Andalucía (L. Medina pers. comm. 2010). The subpopulations in Spain have been estimated to have ca 115,800 individuals (Bañares et al. 2004). In Spain, most of the extinct subpopulations were in the same area (Extremadura) and became extinct due to river and basin transformations by dams there. A few subpopulations from other areas disappeared due to other reasons. In Portugal, some of the subpopulations are disappearing due to changes in crop areas in the Alentejo province.

The population is considered to be severely fragmented since the propagule exchange is by river water flow and an exchange is therefore mostly taking place downstream and linked to rainfall and associated periods of flooding. In the past, it is suspected that former genetic exchange was due to traditional movements of livestock (in Spanish "trashumancia"), when sheep and cattle move to high green areas in spring and return to low areas for the winter. This kind of livestock movement is not practised any longer and thus subpopulations have become more fragmented.
Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Population severely fragmented:Yes
Continuing decline in subpopulations:Yes

Habitat and Ecology [top]

Habitat and Ecology:Marsilea batardae is a perennial, aquatic fern species growing at low elevations (between 0 and 300 m), on clay and sand in temporarily flooded areas (e.g., stream banks), but also occasionally in rock fissures and on stony riverbeds. It inhabits muddy or marshy soil that is virtually permanently inundated, in temperate-warm climates, not far from coastal areas. It can occasionally invade rice fields. Its development is dependent on groundwater level and water quality. The species prefers water that is poor in nutrients and salts, although the biggest subpopulation is found in a rather eutrophic reservoir.
Continuing decline in area, extent and/or quality of habitat:Yes

Use and Trade [top]

Use and Trade: This species is not known to be used.

Threats [top]

Major Threat(s): The main threats are related to the general destruction and degradation of water bodies and modifications of hydrological networks, notably through the construction of dams and canalisation of stream banks. Degradation of water quality is also problematic for the survival of subpopulations. All these factors lead to a reduction of the natural habitat of Marsilea batardae, and seriously threaten its long-term survival.

Conservation Actions [top]

Conservation Actions: Marsilea batardae is protected at the European level under the Habitats Directive 92/43/CEE (Annexes II and IV) and included in Appendix I of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). In Spain, it was listed as Critically Endangered (Dominguez Lozano 2000), but this was amended to Endangered A2ace+3ace+4ace; B2ab(i,ii,iii,iv) (Bañares et al. 2004, Moreno 2008). It is furthermore protected at regional levels in Spain (Andalucía, Castilla-la-Mancha, Extremadura). In Portugal, it was previously listed as Vulnerable (Dray 1985, Walter and Gillett 1997), but due to the construction of the Alqueva dam the listing was amended to Endangered on the basis of the loss of many subpopulations (Rosselló-Graell et al. 2000). This species is protected in Portugal under decree-law n°140/99 (Annexes B-II b/ e B-IV b/) and decree-law n°316/89 (Annexe I). It is included in the seed and spore bank project for the flora affected by the Alqueva dam. It is found in protected areas throughout its range.
The following future conservation measures are being proposed:
  • Control of the water quality and of the hydrological regimes of concerned streams
  • Monitoring of the subpopulations, notably the ones affected by the Alqueva dam (Portugal)
  • Evaluation of the size of the subpopulations
  • Study of the dynamics of the subpopulations, in relation to drainage, irrigation and other hydrological modifications

Classifications [top]

5. Wetlands (inland) -> 5.2. Wetlands (inland) - Seasonal/Intermittent/Irregular Rivers/Streams/Creeks
suitability:Suitable season:resident major importance:Yes
15. Artificial/Aquatic & Marine -> 15.1. Artificial/Aquatic - Water Storage Areas (over 8ha)
suitability:Suitable season:resident major importance:Yes
15. Artificial/Aquatic & Marine -> 15.8. Artificial/Aquatic - Seasonally Flooded Agricultural Land
suitability:Suitable season:resident major importance:Yes
1. Land/water protection -> 1.1. Site/area protection
2. Land/water management -> 2.1. Site/area management
3. Species management -> 3.2. Species recovery

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
  Subject to ex-situ conservation:Yes
In-Place Education
  Included in international legislation:Yes
2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.4. Scale Unknown/Unrecorded
♦ timing:Ongoing ♦ scope:Unknown ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

6. Human intrusions & disturbance -> 6.3. Work & other activities
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Causing/Could cause fluctuations ⇒ Impact score:Low Impact: 5 
→ Stresses
  • 2. Species Stresses -> 2.2. Species disturbance

7. Natural system modifications -> 7.2. Dams & water management/use -> 7.2.11. Dams (size unknown)
♦ timing:Ongoing ♦ scope:Majority (50-90%) ♦ severity:Causing/Could cause fluctuations ⇒ Impact score:Medium Impact: 6 
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

9. Pollution -> 9.2. Industrial & military effluents -> 9.2.3. Type Unknown/Unrecorded
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Slow, Significant Declines ⇒ Impact score:Low Impact: 5 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

9. Pollution -> 9.3. Agricultural & forestry effluents -> 9.3.4. Type Unknown/Unrecorded
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Slow, Significant Declines ⇒ Impact score:Low Impact: 5 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends

Bibliography [top]

Bañares, Á., Blanca, G., Güemes, J., Moreno, J.C. and Ortiz, S. (eds). 2004. Atlas y Libro Rojo de la Flora Vascular Amenazada de España. Dirección General de Conservación de la Naturaleza, Madrid.

Commission of the European Communities. 2009. Composite Report on the Conservation Status of Habitat Types and Species as required under Article 17 of the Habitats Directive. Report from the Commission to the Council and the European Parliament. Brussels.

Dominguez Lozano, F. (ed.). 2000. Lista Roja de Flora Vascular Española (valoración según categorías UICN). pp. 11-38.

Dray, A.M. 1985. Plantas a Proteger em Portugal Continental. Serviço Nacional de Parques, Reservas e Conservação da Natureza, Lisbon.

ICN. 2006. Marsilea batardae Launert. Plano Sectorial da Rede Natura 2000. Lisboa.

IUCN. 2017. The IUCN Red List of Threatened Species. Version 2017-2. Available at: (Accessed: 14 September 2017).

Launert, E. 1983. A new species of Marsilea from Portugal. Boletim da Sociedade Broteriana 2: 99-104.

Moreno, J.C. (coord.). 2008. Lista Roja 2008 de la Flora Vascular Española. Dirección General de Medio Natural y Política Forestal (Ministerio de Medio Ambiente, y Medio Rural y Marino, y Sociedad Española de Biología de la Conservación de Plantas), Madrid.

Prelli, R. 2001. Les Fougères et Plantes Alliées de France et d'Europe Occidentale. Belin, Paris.

Rosselló-Graell, A., Draper, D., Tauleigne Gomes, C. and Correia, A.I.D. 2000. Distribução de Marsilea batardae Launert em Portugal e determinação do seu estatuto de ameaça. Portugaliae Acta Biologica 19: 219-224.

Walter, K.S. and Gillett, H.J. (eds). 1998. 1997 IUCN Red List of Threatened Plants. Compiled by the World Conservation Monitoring Centre. IUCN – The World Conservation Union, Gland, Switzerland and Cambridge, UK.

Citation: Christenhusz, M., Lansdown, R.V., Bento Elias, R., Dyer, R., Ivanenko, Y., Rouhan, G., Rumsey, F. & Väre, H. 2017. Marsilea batardae. In: . The IUCN Red List of Threatened Species 2017: e.T161966A85434785. . Downloaded on 24 June 2018.
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