Because Namibia is mostly arid, much of the flora is typical African dryland vegetation: scrub brush and succulents, such as euphorbia. Along the coastal plain around Swakopmund are the world’s most extensive and diverse fields of lichen; they remain dormant during dry periods, but with the addition of water, they burst into colourful bloom.
Most of the country is covered by tree-dotted, scrub savanna grasses of the genera Stipagrostis, Eragrostis and Aristida. In the south, the grass is interrupted by ephemeral watercourses lined with tamarisks, buffalo thorn and camelthorn. Unique floral oddities here include the kokerboom (quiver tree), a species of aloe that grows only in southern Namibia.
In the sandy plains of southeastern Namibia, raisin bushes (Grewia) and candlethorn grow among the scrubby trees, while hillsides are blanketed with green-flowered Aloe viridiflora and camphor bush.
The eastern fringes of Namib-Naukluft Park are dominated by semidesert scrub savanna vegetation, including some rare aloe species (Aloe karasbergensis and Aloe sladeniana). On the gravel plains east of the Skeleton Coast grows the bizarre Welwitschia mirabilis, a slow-growing, ground-hugging conifer that lives for more than 1000 years.
In areas with higher rainfall, the characteristic grass savanna gives way to acacia woodlands, and Etosha National Park enjoys two distinct environments: the wooded savanna in the east and thorn-scrub savanna in the west. The higher rainfall of Caprivi and Kavango sustains extensive mopane woodland and the riverine areas support scattered wetland vegetation, grasslands and stands of acacias. The area around Katima Mulilo is dominated by mixed subtropical woodland containing copalwood, Zambezi teak and leadwood, among other hardwood species.