Britton & Rose
Cereus nesioticus K.Schum.
The lava cactus (Brachycereus nesioticus) is a species of cactus and the sole species of the genus Brachycereus. The plant is a colonizer of lava fields, hence its common name. It is endemic to the Galápagos Islands.
The plant has soft, furry spines and grows in clumps to a height of about two feet (60 cm). New growth is yellow, turning to brown, which darkens to gray with age. The creamy white flowers are visible in the early morning hours only, and normally fade by 8 in the morning.
As its name suggests, the lava cactus occurs exclusively on barren lava fields, lying at sea level. Not only is it one of the few plants that survive in this extremely dry, challenging habitat, it is often one of the first plants to colonise a fresh lava flow.
Despite the scientific interest that the Galápagos Islands have received ever since Darwin visited in 1835, and the numerous observations of the lava cactus, the biology of this plant remains poorly known.
Like all cacti, this succulent plant is capable of storing moisture in its stems when water is available, enabling it to survive periods of drought, and the spines, which are actually the leaves of the cactus, provide defense against any plant-eating animals.
While the Galápagos are a protected area, and are considered one of the most unspoiled areas remaining on the planet, the fauna and flora of these islands still face major threats, such as introduced species, pressure from increasing tourist numbers, and a decline in the maintenance of protective laws. However, the lava cactus is not currently known to be facing any specific threats. It is considered vulnerable based primarily on its restricted distribution. It is listed as a vulnerable species by the International Union for Conservation of Nature.
The unique biodiversity of the Galápagos has been recognized and these islands are well protected as a result, being classified as a national park and a World Heritage Site. More specifically for the lava cactus, the government of Ecuador prohibits the collection of any plant in the Galápagos.
- Tye, A. 2000. Brachycereus nesioticus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. Downloaded on 25 May 2013.
- Anderson, E. F. The Cactus Family. Timber Press, Portland, Oregon. 2001.
- McMullen, C. K. and Prance, G. Flowering Plants of the Galápagos. Cornell University Press, Ithaca and London. 1999.
- Fitter, J., Fitter, D. and Hosking, D. Wildlife of Galápagos. HarperCollins Publishers Ltd, London. 2000.