This accumulation of sandy material near the crest of the Bordeira represents volcanic ash most likely remobilized by wind, forming some kind of Nabkha around this shrub of Echium vulcanorum, endemic to the mountains of Fogo. Other Echium species are characteristic for the higher parts of other islands of Cape Verde and Macaronesia, such as Echium wildpretii (Tenerife) and Echium candicans (Madeira).