Impatiens gordonii. The IUCN Red List of Threatened Species 2018

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The IUCN Red List of Threatened Species™
ISSN 2307-8235 (online)
IUCN 2008: T203725A128761933
Scope: Global
Language: English
Impatiens gordonii, Seychelles Bizzie Lizzie
Assessment by: Baguette, F., Baboorun, T., Harryba, S., Senterre, B. & Beech, E.
View on www.iucnredlist.org
Citation: Baguette, F., Baboorun, T., Harryba, S., Senterre, B. & Beech, E. 2018. Impatiens gordonii.
The IUCN Red List of Threatened Species 2018: e.T203725A128761933.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Taxonomy
Kingdom Phylum Class Order Family
Plantae Tracheophyta Magnoliopsida Geraniales Balsaminaceae
Taxon Name:ÊÊImpatiens gordonii Horne
Synonym(s):
• Impatiens thomassetii Hook.f.
Common Name(s):
• English: Seychelles Bizzie Lizzie, Wild Balsam
• French: Balsamine sauvage
Taxonomic Notes:
Impatiens gordonii is the only indigenous endemic representative of its genus and its family on the
Seychelles islands. Two names have been used for this endemic Impatiens in the Seychelles, with
Impatiens thomassetii thought to be a synonym of I. gordonii. The affinities of the Seychelles plants,
whether as one or two species, have been considered to be with I. walleriana and I. usambarensis.
Phylogenetic data using ITS provides strong support for the East African species I. usambarensis as sister
to I. gordonii, with I. walleriana sister to that species pair. Crossing experiments supports this in that I.
gordonii, I. walleriana and I. usambarensis all crossed and reciprocally crossed to produce viable seed.
Nine herbarium samples and eighteen live plants of I. usambarensis, I. walleriana , I. gordonii and I.
thomassetii were scored for 21 morphometric characters. Gower-metric principle co-ordinates analysis
recognised I. walleriana, I. usambarensis and I. gordonii as separate morphological entities and
confirmed I. thomassetii as a synonym of I. gordonii. Population differences observed in the morphology
between extant populations of I. gordonii are not considered sufficient to merit taxonomic recognition
of subspecific taxa. The type specimen of I. thomassetii was found to be invalid and a neotype has been
selected (Griffiths in prep).
Assessment Information
Red List Category & Criteria: Critically Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) ver 3.1
Year Published: 2018
Date Assessed: June 11, 2018
Justification:
This shrub is the only indigenous endemic representative of its genus and its family on the Seychelles
islands. The Mahé population originally located within the Morne Seychellois National Park area
(Carlström 1996) is thought to be extinct. The species now only exists on the island of Silhouette, where
the population is protected by the Silhouette National Park. Recent studies by Senterre et al. (2018)
have shown that there are three fragmented subpopulations that contain 89 plants in total. Due to the
population being confined to a few isolated localities this species is at high risk of extinctions. The area
of occupancy (AOO) and extent of occurrence (EOO) is 8 km2. The species is under threat from herbivory
by the Common Striped Hawkmoth (Hippotion eson), by climate change, encroachment of alien plant
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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species (especially by Clidemia hirta), inbreeding depression, habitat destruction and poaching. Due to
the restricted and severely fragmented distribution and declines in mature individuals and range, this
species is listed as Critically Endangered.
Previously Published Red List Assessments
2013 – Critically Endangered (CR)
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T203725A2770808.en
1998 – Endangered (E)
Geographic Range
Range Description:
The species is endemic to the Republic of Seychelles. Even though Impatiens gordonii was originally
recorded from three localities on Mahé (Morne Blanc, Cascade Estate and Morne Seychellois) (Horne
1875; Proctor 1974; Wilson 1980a; Friedmann 1986, 1994; Carlström 1996; Gerlach et al. 1997; Wise
1998), it has only been recorded recently from Trois Frères and the species hasn’t been seen since 2006.
On Silhouette Island, the species was originally recorded from one single population at Anse Mondon
valley. Recent surveys discovered one new population on the South Slope of Mont Dauban and a
knowledgeable inhabitant of Silhouette mentioned another one at Rende d’Avance. Further exploration
is needed to confirm the later one. The species appears to be restricted to submontane and montane
ravine forest on Silhouette Island. The extent of occurrence (EOO) measured as a minimum convex hull
is 0.256 km2 and the area of occupancy (AOO) is 8 km2. Using IUCN guidelines (IUCN Standards and
Petitions Subcommittee 1997), the EOO cannot be less than the AOO so both are estimated to be 8 km2.
Country Occurrence:
Native: Seychelles (Seychelles (main island group))
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Distribution Map
Impatiens gordonii
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Population
There are three known subpopulations of this species. During fieldtrips in 2017 and 2018, 89 mature
individuals were found across two of the subpopulations on Silhouette Island. Further exploration need
to be done to confirm the status of the Rende d’Avance subpopulation. Recent exploration during 2018
did not manage to relocate the Trois Frères subpopulation status on Mahé that was estimated at 14
individuals in 2001 and this population is now thought to be extinct.
Current Population Trend:ÊÊDecreasing
Habitat and Ecology (see Appendix for additional information)
The habitat-type where this species is found appears typically to be “Submontane ravine forests” and
“Montane ravine forests” to some extent (Senterre and Wagner 2014). Submontane ravine forests are
rare, have been intensely deforested in the past, and is at the same time under-explored considering
that most explorers have focussed primarily on the hottest spots of endemism, i.e. in the montane belt.
Impatiens gordonii has never been a very abundant species, considering its narrow ecological range but
suffered from invasive alien species encroachment, herbivory by Hippotion eson (The Common Striped
Hawkmoth) (Griffiths 2013), habitat destruction and poaching from collectors. The fruit is probably
dispersed by endemic birds and reptiles but no direct observations were made. Pollinators are
unknown. The flowering season is thought to be during the wet season, from November to March.
Impatiens gordonii appears to grow mostly on big boulders particularly difficult to explore.
Systems:ÊÊTerrestrial
Use and Trade
A hybrid plant called Impatiens ‘Ray of Hope’ produced from using Impatiens gordonii as one of the
parents used to be sold in the horticultural trade at the Eden Project to raise educational awareness and
funds for the species recovery of this and other endemic plants in the Seychelles. A prior informed
consent with the Seychelles Government was made before sales of this plant occurred and a percentage
of the profits from the sales of Impatiens ‘Ray of Hope’ go directly back to the Seychelles for
conservation of the Seychelles Flora. The production of this hybrid plant did not require collection of
material from the wild (Griffiths 2006).
Threats (see Appendix for additional information)
Climate change is probably the dominant threat to Impatiens gordonii. The submontane belt (being at
the bottom of the cloud belt) is more likely to be affected by climate change (and thus elevation of the
cloud belt) compared to lowland forest species and montane forest species (both being more distant
from the ecological transition in air humidity). In addition, plants most likely to be affected by a possible
change in the cloud belt pattern would certainly be non-woody corticolous (epiphytic) and rupicolous
(growing on rocks) small seeded species (see also Blanc 2002).
The species is also under threat from herbivory by Hippotion eson (The Common Striped Hawkmoth)
(Griffiths 2013). Encroachment of invasive alien plant species, especially by Clidemia hirta and Begonia
ulmifolia is also affecting significantly all subpopulations.
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Finally, inbreeding depression, habitat destruction due to pressures of an increasing human population
on the Seychelles Islands and poaching by plant collectors is impacting the survival of the species. Due
to the existing population being confined to a few isolated localities, this species is at high risk from
accidental extinctions.
Conservation Actions (see Appendix for additional information)
Ninety-three percent of Silhouette Island, has been declared National Park in 2010. The island is owned
by the Seychelles Government that gave a lease to the Islands Development Company (IDC) to manage
it. In 2008, the Silhouette Foundation, regrouping all main stakeholders from Silhouette Island (Ministry
of Environment, Energy and Climate Change (MEECC), Seychelles National Parks Authority (SNPA),
Islands Development Company (IDC) and Island Conservation Society (ICS) and Hilton Labriz Resort &
Spa), was created in order to conserve, rehabilitate and enhance Silhouette ecosystems in harmony with
sustainable low impact human development and eco-tourism. The Silhouette National Park is managed
under the Silhouette Foundation by the Island Conservation Society, a non-governmental organization,
in collaboration with SNPA and MEECC. However, an official Regulation Order is lacking to define clear
rules and regulations within the boundaries of the National Park.
This species is reported from four ex situ collections (BGCI 2018).
It was listed in the 1997 IUCN Red List of Threatened Plants as an Endangered species (Walter and Gillett
1998) and in the Seychelles Red Data Book as Endangered (Gerlach et al. 1997). Griffiths and Matatiken
listed the species as Critically Endangered under the IUCN Red List (assessment completed in 2006).
Credits
Assessor(s): Baguette, F., Baboorun, T., Harryba, S., Senterre, B. & Beech, E.
Reviewer(s): Rivers, M.C.
Contributor(s): Griffiths, A. & Matatiken, D.
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Bibliography
BGCI (Botanic Gardens Conservation International). 2018. PlantSearch online database. Richmond, UK
Available at: www.bgci.org/plant_search.php. (Accessed: 2018).
Blanc, P. 2002. Etre plante à l’ombre des forêts tropicales. Nathan, Paris, France.
Carlström, A. 1996. Endemic and Threatened Plant Species on the Granitic Seychelles. Ministry of
Foreign Affairs, Division of Environment, Victoria.
Friedmann, F. 1990. Fleurs et arbres des Seychelles. Département des finances des Seychelles.
Gerlach, J. 2011. Attempts to establish a new population of the threatened plant Impatiens gordonii on
Silhouette island, Seychelles. Conservation Evidence 8: 87-92.
Gerlach, J. (ed.). 1997. Seychelles Red Data Book 1997. The Nature Protection Trust of Seychelles, Mahé,
Seychelles.
Griffiths, A. 2006. Belzamin sovaz (Impatiens gordonii Horne ex Baker). Kapisen 2(6-7).
Griffiths, A. 2006. Conservation of endemic plant species in the Seychelles, using Impatiens gordonii
Horne ex Baker as a case study. PhD thesis, University of Reading.
Griffiths, A. 2006 (Unpublished). The role of ex-situ management in the conservation of the critically
endangered Seychelles endemic Impatiens gordonii. University of Reading.
Griffiths, A. and Matatiken, D. 2013. Impatiens gordonii. The IUCN Red List of Threatened Species 2013:
e.T203725A2770808.
Hansen S.G. and Laboudallon, V. F. 2013. Flora of the Seychelles a field guide to selected plants. Steen G.
Hansen & Victorin F. Laboudallon.
IUCN. 2006. IUCN Red List of Threatened Species. Available at: www.iucnredlist.org. (Accessed: 04 May
2006).
IUCN. 2018. The IUCN Red List of Threatened Species. Version 2018-2. Available at: www.iucnredlist.org.
(Accessed: 15 November 2018).
IUCN Standards and Petitions Subcommittee. 2017. Guidelines for Using the IUCN Red List Categories
and Criteria. Version 13. March 2017. Prepared by the Standards and Petitions Subcommittee.
International Union for the Conservation of Nature, Cambridge.
Matyot, P. 1996. New Sites for some native plants of Seychelles. Phelsuma 4(40).
Mougal, J. 2005. Going one step further in saving the rare plants of Seychelles. Kapisen 3: 4-6.
Procter, J. 1974. The endemic flowering plants of the Seychelles: an annotated list. Candollea 29: 345-
387.
Senterre, B. and Henriette, E. 2015. Key Biodiversity Areas (KBAs) of the main granitic islands of
Seychelles: An illustrated booklet. Government of Seychelles, UNDP-PCU, Victoria, Mahé, Seychelles.
Senterre B. and Wagner M. 2014. Mapping Seychelles habitat-types on Mahé, Praslin, Silhouette, La
Digue and Curieuse. Government of Seychelles, United Nations Development Programme, Victoria,
Seychelles.
Senterre, B., Baguette, F. and Chong-Seng, L. 2018. Silhouette Adaptive Conservation Management Plan
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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2018-2022 using Bioma: a simple MS Access database.
Senterre, B., Baguette, F., Baboorun, T., Harryba, S. and Beech, E. 2018. Population assessment for three
critically endangered species endemic to Seychelles: Impatiens gordonii, Psychotria silhouettae and
Trilepisium gymnandrum. Island Conservation Society, Botanic Gardens Conservation International,
Victoria, Seychelles.
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
Baguette, F., Baboorun, T., Harryba, S., Senterre, B. & Beech, E. 2018. Impatiens gordonii. The IUCN Red
List of Threatened Species 2018: e.T203725A128761933. http://dx.doi.org/10.2305/IUCN.UK.2018-
2.RLTS.T203725A128761933.en
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External Resources
For Images and External Links to Additional Information, please see the Red List website.
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Appendix
Habitats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Habitat Season Suitability Major
Importance?
1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland - Suitable Yes
1. Forest -> 1.9. Forest - Subtropical/Tropical Moist Montane - Marginal -
0. Root -> 6. Rocky areas (eg. inland cliffs, mountain peaks) - Suitable Yes
Threats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Threat Timing Scope Severity Impact Score
11. Climate change & severe weather -> 11.1. Habitat
shifting & alteration
Ongoing Whole (>90%) Very rapid
declines
High impact: 9
Stresses: 1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
2. Species Stresses -> 2.1. Species mortality
2. Species Stresses -> 2.2. Species disturbance
12. Other options -> 12.1. Other threat Ongoing Whole (>90%) Causing/could
cause fluctuations
Medium
impact: 7
Stresses: 2. Species Stresses -> 2.3. Indirect species effects ->
2.3.5. Inbreeding
5. Biological resource use -> 5.2. Gathering terrestrial
plants -> 5.2.1. Intentional use (species is the target)
Unknown Unknown Slow, significant
declines
Unknown
Stresses: 2. Species Stresses -> 2.1. Species mortality
5. Biological resource use -> 5.2. Gathering terrestrial
plants -> 5.2.4. Motivation Unknown/Unrecorded
Unknown Unknown Slow, significant
declines
Unknown
Stresses: 2. Species Stresses -> 2.1. Species mortality
6. Human intrusions & disturbance -> 6.3. Work &
other activities
Ongoing Unknown Slow, significant
declines
Unknown
Stresses: 2. Species Stresses -> 2.1. Species mortality
2. Species Stresses -> 2.2. Species disturbance
8. Invasive and other problematic species, genes &
diseases -> 8.1. Invasive non-native/alien
species/diseases -> 8.1.1. Unspecified species
Ongoing Whole (>90%) Very rapid
declines
High impact: 9
Stresses: 2. Species Stresses -> 2.1. Species mortality
2. Species Stresses -> 2.2. Species disturbance
8. Invasive and other problematic species, genes &
diseases -> 8.2. Problematic native species/diseases
-> 8.2.2. Named species (Hippotion eson)
Ongoing Whole (>90%) Causing/could
cause fluctuations
Medium
impact: 7
Stresses: 2. Species Stresses -> 2.1. Species mortality
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Conservation Actions in Place
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Actions in Place
In-Place Land/Water Protection and Management
Occur in at least one PA: Yes
Area based regional management plan: Yes
In-Place Species Management
Subject to ex-situ conservation: Yes
Conservation Actions Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Actions Needed
3. Species management -> 3.2. Species recovery
Research Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Research Needed
1. Research -> 1.2. Population size, distribution & trends
3. Monitoring -> 3.1. Population trends
Additional Data Fields
Distribution
Estimated area of occupancy (AOO) (km²): 8
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) (km²): 8
Continuing decline in extent of occurrence (EOO): Yes
Lower elevation limit (m): 250
Upper elevation limit (m): 850
Population
Continuing decline of mature individuals: Yes
Population severely fragmented: Yes
Continuing decline in subpopulations: Yes
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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Habitats and Ecology
Continuing decline in area, extent and/or quality of habitat: Yes
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
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The IUCN Red List of Threatened Species™
ISSN 2307-8235 (online)
IUCN 2008: T203725A128761933
Scope: Global
Language: English
The IUCN Red List Partnership
The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species
Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership.
The IUCN Red List Partners are: Arizona State University; BirdLife International; Botanic Gardens
Conservation International; Conservation International; NatureServe; Royal Botanic Gardens, Kew;
Sapienza University of Rome; Texas A&M University; and Zoological Society of London.
THE IUCN RED LIST OF THREATENED SPECIES™
© The IUCN Red List of Threatened Species: Impatiens gordonii – published in 2018.
http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T203725A128761933.en
11