Wahlenbergia angustifolia

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
PLANTAE	TRACHEOPHYTA	MAGNOLIOPSIDA	CAMPANULALES	CAMPANULACEAE

Scientific Name:

Wahlenbergia angustifolia

Species Authority:

(Roxb) A.DC.

Common Name/s:

English

–

Small Bellflower

Taxonomic Notes:

The St Helena Wahlenbergias are related to each other but not to any other species. The woody habit and bilocular ovary is distinctive. They form a morphological and ecological series:
1. W. angustifolia – creeping leptocaul with small narrow leaves and few flowered inflorescence.
2. W. linifolia – upright, larger, few flowered inflorescence.
3. W. burchellii- larger leaves, many flowered inflorescence.
4. W. roxburghii – upright pachycaul with wide leaves and many flowered inflorescence.

W. angustifolia is at the drier end of the series and is the only one which is relatively common. W. burchellii and W. roxburghii are extinct. (Cronk 2000).

Assessment Information [top]

Red List Category & Criteria:	Endangered B2ab(i,iii) ver 3.1
Year Assessed:	2003
Assessor/s:	Cairns-Wicks, R.
Reviewer/s:	Cronk, Q. & Clubbe, C. (South Atlantic Island Plants Red List Authority)
Justification: A continuing decline is inferred due to the declining quality of habitat at sites where it occurs and susceptibility to crowding by other species such as Olea africana and Phormium tenax. Whilst it may occur at more than five locations, subpopulation sizes in locations other than South West Cliffs (Old Joan Point) are small and fragmented.

Geographic Range [top]

Range Description:	Found on Old Joan Point Cliffs, Peak Dale and Deep Valley, growing on cliffs associated with the Gumwood, Mt Vesey. W. angustifolia has also been recorded at the Depot, Devil’s Hole Cap, Thompsons Wood, Fairyland, Rock Mount, Cason’s, Bevin’s, Grape Vine Gut, Sandy Bay Ridge, Cole’s Rock and Great Stone Top (Cronk 2000). These sites are predominately unmanaged areas where alien plants are the dominant vegetation type. It is therefore likely that where the small bellflower still persists it is under intense competition from the alien plants. W. angustifolia has an estimated population of some 1,000 plants. Subpopulations are highly fragmented and small.
Countries:	Native: Saint Helena

Range Description:

Found on Old Joan Point Cliffs, Peak Dale and Deep Valley, growing on cliffs associated with the Gumwood, Mt Vesey.

W. angustifolia has also been recorded at the Depot, Devil’s Hole Cap, Thompsons Wood, Fairyland, Rock Mount, Cason’s, Bevin’s, Grape Vine Gut, Sandy Bay Ridge, Cole’s Rock and Great Stone Top (Cronk 2000). These sites are predominately unmanaged areas where alien plants are the dominant vegetation type. It is therefore likely that where the small bellflower still persists it is under intense competition from the alien plants.

W. angustifolia has an estimated population of some 1,000 plants. Subpopulations are highly fragmented and small.

Countries:

Native:

Saint Helena

Population [top]

Population Trend:	Decreasing

Population Trend:

Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	An endemic to St Helena. Although W. angustifolia is found close to High Peak, it is not in the same situation as the large Bellflower. However, it is suspected that where the two species grow in proximity to each other, hybridization can occur. Intermediate size has been observed inW. linifolia (Kerr 1953 referred to in Cronk (2000)) and also recently in the second subpopulation at High Peak and in the Environmental Conservation Section Nursery, Scotland (R. Cairns-Wicks, pers. obs.). Kerr (1953) suggests that intermediates are either interspecific hybrids or there is great variation in growth and size of W. linifolia. Leaf material of W. angustifolia and W. linifolia was sent to RBG Kew for DNA testing to investigate this further.
Systems:	Terrestrial

Habitat and Ecology:

An endemic to St Helena. Although W. angustifolia is found close to High Peak, it is not in the same situation as the large Bellflower. However, it is suspected that where the two species grow in proximity to each other, hybridization can occur. Intermediate size has been observed inW. linifolia (Kerr 1953 referred to in Cronk (2000)) and also recently in the second subpopulation at High Peak and in the Environmental Conservation Section Nursery, Scotland (R. Cairns-Wicks, pers. obs.). Kerr (1953) suggests that intermediates are either interspecific hybrids or there is great variation in growth and size of W. linifolia. Leaf material of W. angustifolia and W. linifolia was sent to RBG Kew for DNA testing to investigate this further.

Systems:

Terrestrial

Threats [top]

Major Threat(s):	Competition from introduced alien species as well as small and fragmented subpopulation sizes, are the major threats to W. angustifolia. Hybridization is also a threat, however, this is probably posses a greater threat to W. linifolia as this is rarer.

Major Threat(s):

Competition from introduced alien species as well as small and fragmented subpopulation sizes, are the major threats to W. angustifolia. Hybridization is also a threat, however, this is probably posses a greater threat to W. linifolia as this is rarer.

Conservation Actions [top]

Conservation Actions:	Protected under the Endangered Endemic and Indigenous Species Protection Ordinance No 7 of 1996. subpopulations across part of its range are found at Man and Horse Cliffs and Mt Vesey, both are within the boundary of Sandy Bay National Park, that is designated in the revised SLUP 1998/9. However, specific Protected Area legislation and management plans have not yet been developed or implemented. There is currently no specific conservation action for this species.

Conservation Actions:

Protected under the Endangered Endemic and Indigenous Species Protection Ordinance No 7 of 1996. subpopulations across part of its range are found at Man and Horse Cliffs and Mt Vesey, both are within the boundary of Sandy Bay National Park, that is designated in the revised SLUP 1998/9. However, specific Protected Area legislation and management plans have not yet been developed or implemented. There is currently no specific conservation action for this species.

Citation:	Cairns-Wicks, R 2003. Wahlenbergia angustifolia. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 09 February 2012.
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