Sea spider iris (Ferraria crispa)

Description

What’s the World’s Favourite Species?

Sea spider iris fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Sea spider iris description

The sea spider iris is distinctive for the unusual flowers it bears and the acrid scent of rotting flesh it emits. The brown or yellowish, speckled flowers measure around 30 millimetres across and the petals have crispy margins, hence the scientific name of this species, crispa ⁽⁵⁾. The leaves of the sea spider iris are sword-shaped and slightly fleshy ^{(3) (5)}, and they partly cover the branched, straight or slightly twisted stem ⁽⁶⁾. A swollen stem base of the sea spider iris forms an underground storage organ, or corm, which stores food for the plant ^{(3) (7)}.

Also known as

black flag.

Size

Height: 40 – 100 cm ⁽³⁾

Sea spider iris biology

The sea spider iris bears its pungent, peculiar flowers between August and October ⁽³⁾, but each flower lasts for just a single day ⁽⁶⁾. Little information is available regarding the biology of the sea spider iris, but it can be presumed to be similar to that of other Ferraria species. Ferraria species are known to be pollinated by dung, flesh and game flies, and also by bees and wasps. The dull, mottled patterning of the flowers, along with their unpleasant rotting flesh or fermenting fruit scent attract flies ⁽¹⁾, who are duped into thinking this is a suitable place to lay eggs ⁽⁸⁾. The flies walk all over the flowers trying, and failing, to find a suitable place to lay their eggs ⁽⁸⁾, and leave dusted liberally with bright orange pollen. While the sea spider iris does not provide insects with a suitable place to lay eggs, pollinators are rewarded with sips of concentrated nectar ⁽¹⁾.

Sea spider iris range

Endemic to the Cape Floristic Region, a ‘hot-spot’ of plant diversity in south-western South Africa. The sea spider iris is distributed from Lamberts Bay, south and east to Mossel Bay ⁽³⁾.

Sea spider iris habitat

The sea spider iris mainly inhabits coastal areas, where it grows on sandstone or granite rocks ⁽³⁾.

Sea spider iris status

Subspecies Ferraria crispa nortieri is classified as Vulnerable (VU) and Ferraria crispa crispa is classified as Least Concern (LC) on the Interim Red Data List of South African Plant Taxa ⁽⁴⁾.

Sea spider iris threats

The subspecies F. c. nortieri is classified as Vulnerable ⁽⁴⁾, but at present there is no information available to indicate what specific threats this species faces. However, as it is restricted to the Cape Floristic Region, it is likely to be impacted by urban development, the encroachment of agriculture and the invasion of alien species, threats that are known to be affecting the region’s habitat and numerous endemic plant species ^{(9) (10)}.

Sea spider iris conservation

Within the Cape Floristic Region there are a number of protected areas ⁽¹¹⁾, and a number of conservation organisations are working to conserve the botanically rich habitat of the Cape Floristic Region. Conservation actions include purchasing land to protect it from the threats of encroaching agriculture and urban development ⁽¹²⁾, the removal of alien plants, and the establishment of new protected areas ⁽¹⁰⁾; measures which should benefit the vulnerable subspecies F. c. nortieri.

Find out more

For further information on the Cape Floristic Region and its conservation see:

• Conservation International: Biodiversity Hotspots:
  www.biodiversityhotspots.org/xp/hotspots/cape_floristic

Authentication

Glossary

Cape Floristic Region

An area occupying about 90,000 square kilometres in South Africa that contains an incredibly high diversity of plant species (around 8,700 species), of which 68 percent are found no where else.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Pollination

The transfer of pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Subspecies

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

References

1. Goldblatt, P. and Manning, J.C. (2006) Radiation of pollination systems in the Iridaceae of sub-Saharan Africa. Annals of Botany, 97(3): 317 - 344.
2. Angiosperm Phylogeny Website (February, 2008)
   http://www.mobot.org/mobot/research/apweb/welcome.html
3. Goldblatt, P. and Manning, J. (2000) Cape Plants: A Conspectus of the Cape Flora of South Africa. National Botanical Institute of South Africa, Pretoria .
4. Threatened Species Programme. (2007) Interim Red Data List of South African Plant Taxa. South African National Biodiversity Institute, Pretoria, South Africa. Available at:
   http://www.sanbi.org/biodiversity/reddata.htm
5. Paterson-Jones, C. and Manning, J. (2007) Ecoguide Fynbos. Briza Publications, Pretoria, South Africa.
6. Renosterveld Trust (February, 2008)
   http://www.renosterveld.org/data.html
7. Allaby, M. (1998) Dictionary of Plant Sciences. Oxford University Press, Oxford.
8. Donaldson, J., Anderson, B. and Von Hase, A. (2003) Field Notes. Renosterveld Information Sharing Session, Groote Post Farm, Darling.
9. Rouget, M., Richardson, D.M., Cowling, R.M., Lloyd, J.W. and Lombard, A.T. (2003) Current patterns of habitat transformation and future threats to biodiversity in terrestrial ecosystems of the Cape Floristic Region, South Africa. Biological Conservation, 112: 63 - 85.
10. Conservation International: Biodiversity Hotspots (February, 2008)
    http://www.biodiversityhotspots.org/xp/hotspots/cape_floristic/Pages/default.aspx
11. UNEP-WCMC: Cape Floral Protected Areas of South Africa (February, 2008)
    http://www.unep-wcmc.org/sites/wh/pdf/CAPE%20FLORAL%20REGION.pdf
12. Fauna and Flora International (February, 2008)
    http://www.fauna-flora.org/fynbos.php