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. 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.