Isoetes boryana 

Scope: Global & Europe
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Lycopodiopsida IsoËtales IsoËtaceae

Scientific Name: Isoetes boryana Durieu
Common Name(s):
English Gascoyne Quillwort
Isoëtes velata A.Braun var. boryana (Durieu).M.I.Romero & C.Real
Isoëtes boryana Durieu
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: Isoetes boryana falls within the I. longissima/I. velata group (Greuter and Troia 2014), a taxonomically difficult suite of species which merits further research. Prelli (2001) questions the validity of I. boryana as a species, while Romero and Real (2005) propose its treatment as a variety of I. velata. In France, this species is considered valid and similar to I. tenuissima.

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v) ver 3.1
Year Published: 2017
Date Assessed: 2016-06-01
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.
Isoetes boryana is an aquatic quillwort listed as Endangered because it has a restricted distribution with an estimated extent of occurrence (EOO) of 854-1,412 km² and an estimated area of occupancy (AOO) of 56 km². Based on the impact of eutrophication and water management, the species occurs at three locations and there is a continuing decline in the AOO, habitat quality, number of mature individuals, subpopulations and locations, since the species disappeared from two ponds. Proper management and protection of the species is needed in order to improve the status of this species.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Isoetes boryana is endemic to southwestern France (Gironde and Landes, in ponds of the Gascogne Gulf). The total geographic range for the species has been estimated to be 854 km² (N. Juillet pers. comm. 2010). Its EOO is 854-1,412 km², but within this area its AOO is only 56 km². Reports of this taxon from Spain belong to I. longissima.
Countries occurrence:
France (France (mainland))
Additional data:
Estimated area of occupancy (AOO) - km2:56Continuing decline in area of occupancy (AOO):Yes
Estimated extent of occurrence (EOO) - km2:854-1412
Number of Locations:3Continuing decline in number of locations:Yes
Range Map:Click here to open the map viewer and explore range.

Population [top]


The species occurs locally in large stands, but it is known from only three localities (three ponds). Its AOO is declining, as two localities have been lost in Landes. The population trend is decreasing.

Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes

Habitat and Ecology [top]

Habitat and Ecology:Isoetes boryana occurs on the sandy edges of ponds or shallow lakes, on siliceous substrate, usually close to the sea (Tutin et al. 1964, Prelli 2001).
Systems:Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat:Yes

Use and Trade [top]

Use and Trade:

This species is not used.

Threats [top]

Major Threat(s): The main threats to this species are related to unfavourable water management (including drainage, pollution and disturbances), eutrophication due to agriculture and water recreation. Based on the impact of euthrophication and water management the species occurs at three locations.

Conservation Actions [top]

Conservation Actions: This species is listed on Annexes II and IV of the Habitats Directive and on Annex I of the French National List of Protected Species. It is listed as Endangered (B1ab(iii)+2ab(iii)) (UICN France, FCBN and MNHN 2012). Proper management and protection of the sites or acquisition of the land by the National Littoral Conservatoire would be important for this species. Species recovery through ex-situ conservation may be an additional way of improving the subpopulations of this species. It is not present in protected areas.

Citation: Christenhusz, M., Lansdown, R.V., Bento Elias, R., Dyer, R., Ivanenko, Y., Rouhan, G., Rumsey, F. & Väre, H. 2017. Isoetes boryana. The IUCN Red List of Threatened Species 2017: e.T161833A85430458. . Downloaded on 20 September 2018.
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