Red disa (Disa uniflora)

Description

Red disa fact file

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

Red disa description

The red disa is a member of the orchid family, a group of plants prized for their spectacularly beautiful flowers ⁽³⁾, and the emblem of the Cape Province of South Africa in which it grows ⁽⁴⁾. It can bear up to six showy flowers, which may be shades of red, pink or occasionally yellow ^{(2) (5)}, and has simple leaves that alternate down the stem ⁽³⁾. The flower consists of three petals, one of which is quite distinct from the other two. This petal, called the lip or labellum, lies at the base of the flower and acts as a landing platform to attract a particular species of butterfly to its pollen ⁽⁶⁾. The red disa was discovered by a Swedish physician and botanist who is thought to have named it after Queen Disa from a famous Swedish saga ⁽⁶⁾.

Also known as

Pride of Table Mountain.

Size

Height: up to 1 m ⁽²⁾

Red disa biology

The red disa is pollinated solely by the mountain pride butterfly, Meneris tulbaghia, and it is the abundance of this butterfly that dictates the success of the red disa in different habitats. Those plants growing in a rocky gorge are far more successful than those in an open valley, as the mountain pride butterfly prefers rocky, sheltered habitats ⁽⁷⁾. Red disas are evergreen plants but bear flowers only during the summer months, from December to March, with a peak flowering period in mid-February ⁽⁵⁾. Flowers of the red disa produce nectar to tempt the mountain pride butterfly to feed, and when the butterfly drinks from the long, tubular nectaries that store the nectar, pollen is deposited on their feet, facilitating pollination ⁽⁸⁾. The seed of the red disa is a relatively large balloon-shaped structure; a shape which is thought to have evolved to be suited to dispersal by water ⁽⁹⁾, perfectly adapted to their stream-side habitat.

Red disa range

Grows in the Cape Floristic Region, South Africa ⁽⁵⁾.

Red disa habitat

The red disa is found along stream banks, waterfalls and wet cliffs on Table Mountain and other mountain localities of the Western Cape ⁽⁵⁾.

Red disa status

Listed on Appendix II of CITES ⁽¹⁾.

Red disa threats

The Cape Floristic Region, in which the red disa is found, is one of the richest areas for plant diversity in the world, with more than 69 percent of species found no where else ⁽⁴⁾. Unfortunately, the unique floral biodiversity of this region is under threat from agricultural expansion. Farming of rooibos tea, honeybush tea, cut flowers and vineyards are all encroaching on natural areas ⁽⁴⁾. In addition, the invasion of alien plant species, introduced from countries such as Australia and Canada, is altering natural fire frequencies and eliminating native species, upsetting the delicate ecological balance ⁽⁴⁾.

Red disa conservation

The red disa is listed on Appendix II of the Convention of International Trade in Endangered Species (CITES), meaning that trade in this beautiful and popular flower should be controlled to ensure it is compatible with the species’ survival ⁽¹⁾. About 14 percent of the Cape Floristic Region falls into protected areas ⁽⁴⁾, so it is likely that some populations of the red disa receive some form of protection.

Find out more

For further information on the Cape Floristic Regions see:

• Conservation International Biodiversity Hotspots: Cape Floristic Region:
  www.biodiversityhotspots.org/xp/Hotspots/cape_floristic/Pages/default.aspx

Authentication

References

1. CITES (September, 2007)
   http://www.cites.org
2. Orchids of the World (October, 2007)
   http://www.orchids.mu/
3. Heywood, V.H. (1978) Flowering Plants of the World. Oxford University Press, Oxford.
4. Conservation International Biodiversity Hotspots: Cape Floristic Region (October, 2007)
   http://www.biodiversityhotspots.org/xp/Hotspots/cape_floristic/Pages/default.aspx
5. PlantzAfrica (October, 2007)
   http://www.plantzafrica.com/plantcd/disauniflora.htm
6. Pettersson, B. (1985) The Etymology of the Generic Name Disa Bergius (Orchidaceae). Taxon, 34(3): 457 - 461.
7. Johnson, S.D. and Bond, W.J. (1992) Habitat dependent pollination success in a Cape orchid. Oecologia, 91(3): 455 - 456.
8. Royal Botanic Gardens, Kew (October, 2007)
   http://www.kew.org/archive/events/orchids2004/orchid_facts/1disa.html
9. Kurzweil, H. (1992) Seed morphology in Southern AfricanOrchidoideae (Orchidaceae). Plant Systematics and Evolution, 185: 229 - 247.