Café marron (Ramosmania rodriguesii)

French: Café Marron
KingdomPlantae
PhylumTracheophyta
ClassMagnoliopsida
OrderRubiales
FamilyRubiaceae
GenusRamosmania (1)
SizeHeight: 2 - 4 m (2)

Classified as Critically Endangered (CR) on the IUCN Red List (1)

On sending his pupils out to explore for rare and interesting plants, a school teacher on the island of Rodrigues in 1980 was astounded when one of his pupils returned with a fresh cutting of a plant believed to be extinct (2) (4). The plant was the café marron, one of two congeneric tree species bearing the same common name, both of which had last been seen in the 1940s. The café marron grows as a shrub or small tree, with oppositely arranged leaves that exhibit two very different forms on the same individual plant. While the juvenile leaves are linear, or narrowly elliptic in shape, and can reach up to 30 cm in length, the adult leaves are usually half as long and have a more broadly elliptic profile. The sweetly-scented, hermaphroditic flowers are greenish-yellow at first but become pure white at maturity (2).

The café marron is endemic to the island of Rodrigues, Mauritius, where it is presently known from just a single wild individual (2) (4).

Historically known from tropical, humid forest (2).

Like many plants with hermaphroditic flowers, the café marron is self-incompatible (2), meaning that the pollen from the flowers of an individual plant cannot fertilise the pistils of its own flowers (5). This common strategy prevents plants from inbreeding, whilst promoting out-crossing, which increases the genetic vigour of offspring (5). However, the inability to self-fertilise becomes somewhat less advantageous when a plant’s global population is reduced to a single individual.

Along with much of Rodrigues’ native vegetation, it was probably a combination of introduced herbivores, invasive alien plants, and habitat loss that decimated the café marron population (6). Indeed, goats had reduced the remaining wild specimen to a small, half-eaten shrub when it was first discovered. Owing to the unprecedented level of scientific interest that surrounded the little plant in the aftermath of its re-discovery, local people became convinced of the plant’s medicinal properties (2). Consequently, there was a period before the erection of multiple fences (1) (2), and even the installation of a guard, when people were intent on removing branches, twigs and leaves from the hapless plant (7). Although the protection of the single wild specimen has now been secured, the real obstacle to the species’ long-term survival is establishing an efficient means of propagating a non-sterile population from an effectively sterile plant (2).

Relatively soon after the re-discovery of the café marron, cuttings from the surviving plant were sent to Kew Gardens in England. At Kew, scientists were successful in propagating clones of the plant from the cuttings but could not find a means of successfully fertilising the flowers in order to produce seeds (2). Then in 2003, a major breakthrough was made when researchers discovered a technique to bypass the plant’s self-incompatibility mechanism, resulting in the production of a small number of viable seeds (2) (8). Since then, several seeds have been successfully germinated at a nursery on Rodrigues, with the aim of eventually re-vitalising a wild population on the island (9).

To find out more about conservation on Rodrigues see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (March, 2009)
    http://www.iucnredlist.org
  2. Royal Botanic Gardens, Kew. (2009) Pers. comm.
  3. Royal Botanic Gardens, Kew (March, 2009)
    http://www.rbgkew.org.uk/whatsnew/ramosmania.html
  4. Silva, N.F. and Goring, D.R. (2001) Mechanisms of self-incompatibility in flowering plants. Cellular and Molecular Life Sciences, 58: 1988 - 2007.
  5. WWF (March, 2009)
    http://www.worldwildlife.org/wildworld/profiles/terrestrial/at/at0120_full.html
  6. National Public Radio - The Little Coffee Plant that Wouldn't Die (March, 2009)
    http://www.npr.org/templates/story/story.php?storyId=5307047
  7. Smithsonian National Museum of Natural History Plant Conservation Unit. (2003) Rare Mauritian Plant Produces Fruit. Biological Conservation Newsletter, 227: 1 - .
  8. Mauritian Wildlife Foundation. (2007) Kew Gardens gives hope of survival for the café marron. Mauritian Wildlife Foundation Newsletter, 8: 1 - . Available at:
    http://www.mauritian-wildlife.org