Divided by mountains, there is a thriving desert on South Africa’s Western Cape where bushy, sandy plains belie beautiful, botanical treasures. This unassuming landscape is the world’s only arid plant hotspot—and home to a third of all succulent plant species in the world. Part of the region’s Sanbona Wildlife Reserve, the area of land falling under the “rain shadow” of the Warmwaterberg mountains, supports two separate biomes: Fynbos and Succulent Karoo. Both are rich with life, the reserve explains, some of which are found nowhere else on Earth. Where herds of elephant, black rhino, and Cape buffalo once roamed, Succulent Karoo—the most species-rich semidesert on the planet—now boasts some 3,000 succulent plant species. Forty percent are endemic and don’t grow anywhere else. Upon closer inspection, the Karoo’s low, gray-brown bushes are blooming with bright flowers in reds, pinks, purples, yellows, and oranges. The succulents survive the semidesert climate by storing …