Cryptocoryne thwaitesii
Schott
Pays · région · aire protégée · écorégion · biome
Graphe en cours d’indexation
Calcul du tissu écologique de Cryptocoryne thwaitesii.
Le graphe apparaîtra automatiquement dès que le calcul est terminé (rafraîchissement toutes les 5s).
Liste rouge IUCN
VU · Vulnérablecritères B1ab(i,ii,iii,v)+2ab(i,ii,iii,v)↘Décroissante- Évaluation
- 2023 · v3.1
- Altitude
- 20 – 450 m
- Profondeur
- – m
État de la populationTexte officiel évaluation IUCNExpert
This species appears to have declined over the last 40 years (C. Kasselmann pers. comm.) due to over-collection and there are river sections where this has caused the loss of populations. Two of the sites from which this species has been recorded are now urban centres and are considered likely to have been lost.
Menaces identifiées(5 menaces classées CMP-IUCN)
5_2_1Intentional use (species is the target)UnknownUnknownOngoing9_3_1Nutrient loadsSlow, Significant DeclinesMajority (50-90%)Ongoing9_3_2Soil erosion, sedimentationSlow, Significant DeclinesMajority (50-90%)Ongoing1_1Housing & urban areasVery Rapid DeclinesMajority (50-90%)Ongoing2_1_2Small-holder farmingVery Rapid DeclinesMajority (50-90%)Ongoing
Description complète des menacesTexte détaillé évaluation IUCNExpert
The habitat where this species occurs is declining in area and becoming degraded because of logging and conversion into agricultural land. It is also threatened by over-collection.
Habitats préférentiels (classification IUCN)
5_1Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)★
Mesures de conservation recommandéesStratégies de conservation IUCNExpert
There are no specific conservation actions in place for this species. It is known to occur in the Kottawa Forest Reserve and was classed as EN B1ab(i,ii,iii)+2ab(i,ii,iii) by Yakandawala (2012). There is an urgent need to derive an up-to-date assessment of the conservation condition of all known populations, combined with surveys to locate other extant populations.
Stress écologiques (9)Stresses Classification — IUCNExpert
1_1Ecosystem conversion1_1Ecosystem conversion1_2Ecosystem degradation1_2Ecosystem degradation2_1Species mortality2_1Species mortality2_1Species mortality2_1Species mortality2_1Species mortality
Usage & commerce (1)Use & Trade — IUCNExpert
13Pets/display animals, horticultureinternationalnational
Priorités de recherche (3)Research Needed Classification — IUCNExpert
1_2Population size, distribution & trends1_5Threats3_1Population trends
Niche IUCN globaleRealms · Systems · LMEs · Growth forms · FAOs — biogéographie IUCNExpert
Royaumes biogéographiques
Indomalayan
Systèmes (terrestre/eau douce/marin)
Freshwater (=Inland waters)
Formes de croissance
Forb or HerbHydrophyte
Références bibliographiques (6)Sources scientifiques de l'évaluation IUCNExpert
- IUCN. 2023. The IUCN Red List of Threatened Species. Version 2023-1. Available at: <a href="www.iucnredlist.org">www.iucnredlist.org</a>. (Accessed: 07 December 2023).
- Bastmeijer, J.D. 2020. Crypts pages: <i>Cryptocoryne thwaitesii</i>. Available at: <a href="https://crypts.home.xs4all.nl/Cryptocoryne/Gallery/thw/thw.html">https://crypts.home.xs4all.nl/Cryptocoryne/Gallery/thw/thw.html</a>.
- Yakandawala, D. 2012. Present Status of Fresh Water Aquatic Flora in Sri Lanka. In: D.K. Weerakoon and S. Wijesundara (eds), <i>The National Red List 2012 of Sri Lanka; Conservation Status of the Fauna and Flora</i>, pp. 186-196. Ministry of Environment, Colombo.
- Jacobsen, N. 1987. <i>Cryptocoryne</i>. In: M.D. Dassanyake and F.R. Forsberg (eds), <i>A revised Handbook to the Flora of Ceylon</i>, pp. 85-99.
- Graaf, A. de and Arends, J.C. 1986. The occurrence of <i>Cryptocoryne</i> and <i>Lagenandra</i> (Araceae) on Sri Lanka. <i>Nordic Journal of Botany</i> 6: 757-764.
- Jacobsen, N. 1976. Notes on <i>Cryptocoryne</i> of Sri Lanka (Ceylon). <i>Botaniska Notiser</i> 129: 179-190.
Évaluateurs & contributeurs (3)Personnes ayant contribué à l'évaluation IUCNExpert
assessor
Lansdown, R.V.
contributor
Kasselmann, C.
evaluator
Yakandawala, D.M.D. & Jacobsen, N.
Lansdown, R.V. 2023. Cryptocoryne thwaitesii. The IUCN Red List of Threatened Species 2023: e.T175657168A197731222. Accessed on 05 May 2026.
Distribution mondiale
Calcul de la distribution GBIF· ~10–60 s
Phénologie
Calcul du calendrier d'apparition· ~5–30 s