Lachenalia sessiliflora

Taxonomy
Scientific Name
Lachenalia sessiliflora Andrews
Higher Classification
Monocotyledons
Family
HYACINTHACEAE
Synonyms
Lachenalia muirii W.F.Barker
National Status
Status and Criteria
Vulnerable B1ab(iii,v)
Assessment Date
2019/11/26
Assessor(s)
D. Raimondo & L. von Staden
Justification
Lachenalia sessiliflora is a range-restricted species with an extent of occurrence (EOO) of 2358 km². It is suspected to be declining due to competition from alien invasive plants, as the only recent observations are from protected areas where there are efforts to control alien invasive plants. It is known to remain at five locations, but could still be present at up to 12, but this number is very uncertain as the species has not been recorded at many of these sites since the 1960s.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
This species has a restricted distribution range on the lowlands of the Western Cape's southern coast, where it occurs from Bredasdorp to Stilbaai.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Overberg Dune Strandveld, Canca Limestone Fynbos, De Hoop Limestone Fynbos, Agulhas Limestone Fynbos, Hartenbos Strandveld
Description
It occurs on limestone hills and flats near the coast. Mature fruits split open and the seeds are dispersed locally. Pollinators are unknown.
Threats
This species is threatened across its range by competition from dense infestations of alien invasive plants that are outcompeting native species. There are efforts to clear alien invasive plants inside protected areas, but not outside. Alien invasive plant control requires ongoing effort, as they continue to re-emerge from soil-stored seed banks, particularly following fires. Therefore competition from alien invasive plants remains a threat to subpopulations inside as well as outside protected areas. It is also threatened by ongoing habitat loss to coastal development around Arniston, Puntjie and Stilbaai. It has lost habitat to agricultural expansion around Bredasdorp Poort, Cape Infanta, and inland of Stilbaai in the past, but its habitat is only marginally suited to crop cultivation, and further agricultural expansion is not a significant threat.
Population

Historical records indicate that this species was once common in coastal limestone fynbos between Bredasdorp and Stilbaai. It has been recently observed at only five locations, all from protected areas where there are efforts being made to control alien invasive plants. It is not known whether this species still persists anywhere outside protected areas. There are at least seven other locations outside protected areas where the species was last recorded in the 1960s and 1980s that urgently need to be surveyed to determine whether they are still extant. The population trend is not known, but it is suspected to be declining. This species requires monitoring.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Lachenalia sessiliflora AndrewsVU B1ab(ii,iii,iv,v)2017.1
Lachenalia muirii W.F.BarkerVU B1ab(ii,iii,iv,v)Raimondo et al. (2009)
Lachenalia muirii W.F.BarkerNot Threatened Hilton-Taylor (1996)
Lachenalia muirii W.F.BarkerUncertain Hall et al. (1980)
Bibliography

Duncan, G.D. 2012. The genus Lachenalia. Kew Publishing, Royal Botanic Gardens, Kew.


Goldblatt, P. and Manning, J.C. 2000. Cape Plants: A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.


Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.


Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.


Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.


Citation
Raimondo, D. & von Staden, L. 2019. Lachenalia sessiliflora Andrews. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2020/07/10

Comment on this assessment Comment on this assessment
Distribution map

© C. Paterson-Jones


Search for images of Lachenalia sessiliflora on iNaturalist