One century ago, the English botanist Henry Ridley traveled to Malaysia and climbed Mount Tahan in (what is now) Pahang. During his climb, Ridley discovered two species of pitcher plants (Nepenthes). He described the first one under the name Nepenthes gracillima in 1908, and recorded that it produces long, slender pitchers that are predominantly black mottled with green blotches. Sixteen years later, Ridley (1924) described the second species which he had encountered on Mount Tahan, and he named that plant N. alba for it produces smaller, predominantly white pitchers.