Question: Which plant genus, Atalaya or Vriesea, has three species known to grow naturally in southern Africa?

Context paragraphs:
Buckinghamia: Buckinghamia is a genus of only two known species of trees, belonging to the plant family Proteaceae.  They grow naturally only (endemic) in the rainforests of the wet tropics region of north eastern Queensland, Australia.  The ivory curl flower, "B. celsissima", is the well known, popular and widely cultivated species in gardens and parks, in eastern and southern mainland Australia, and additionally as street trees north from about Brisbane.  The second species, "B. ferruginiflora", was only recently described in 1988.

Harpullia: Harpullia is a genus of about 27 species known to science, of small to medium-sized rainforest trees, constituting part of the plant family Sapindaceae.  They have a wide distribution ranging from India eastwards through Malesia, Papuasia and Australasia to the Pacific Islands.  They grow naturally usually in or on the margins of rainforests or associated vegetation.

Eupomatia: Eupomatia is a genus of three flowering shrub species known to science, of the Australian continent ancient family Eupomatiaceae.  The Eupomatiaceae have been recognised by most taxonomists and classified in the plant order Magnoliales.  The three species of shrubs or small trees grow naturally in the rainforests and humid eucalypt forests of eastern Australia and New Guinea.  The type species "Eupomatia laurina" was described in 1814 by Robert Brown.

Vriesea: Vriesea is a genus of the botanical family Bromeliaceae, subfamily

Arytera: Arytera is a genus of about twenty–eight species known to science, of trees and shrubs and constituting part of the plant family Sapindaceae.  They grow naturally in New Guinea, Indonesia, New Caledonia, Australia, the Solomon Islands, Vanuatu, Fiji, Samoa, Tonga; and the most widespread species and type species "A. littoralis" grows throughout Malesia and across Southeast Asia, from NE.  India, southern China, Borneo, Malaysia, Singapore, Indonesia and the Philippines to as far east as New Guinea and the Solomon Islands.

Gymnostoma: Gymnostoma is a genus of about eighteen species of trees and shrubs, constituting one of the four genera of the plant family Casuarinaceae.  The species grow naturally in the tropics, including at high altitudes having temperate climates, in forests in the region of the western Pacific ocean and Malesia.  In New Caledonia, published botanical science describes eight species found growing naturally, which botanists have not found anywhere else (endemics).  Additional species have been found across Burma, Sumatra, Borneo, the Philippines, Sulawesi, Ambon Island, the Moluccas, New Guinea, the Bismarck Archipelago, the Solomon Islands, and one endemic species each in Fiji and the Wet Tropics of Queensland, Australia.

Lasjia: Lasjia is a genus of five known species of trees, constituting part of the plant family Proteaceae.  Three species grow naturally in north–eastern Queensland, Australia and two species in Sulawesi, Indonesia.  Descriptively they are the tropical or northern macadamia trees group.  "Lasjia" species characteristically branched compound inflorescences differentiate them from the "Macadamia" species, of Australia, which have characteristically unbranched compound inflorescences and only grow naturally about 1000 km further to the south, in southern and central eastern Queensland and in north–eastern New South Wales.

Carnarvonia: Carnarvonia is a flowering plant genus of a single species, commonly named red oak or red silky oak and constituting part of the plant family Proteaceae.  The single species named Carnarvonia araliifolia grows to large trees of 30 m or more.  They grow naturally only (endemic) in the Wet Tropics rainforests region of north-eastern Queensland, Australia.  The species has two described varieties, C. araliifolia" var.  "araliifolia and C. araliifolia" var.  "montana, and the common names are used for both.

Atalaya (plant): Atalaya is a genus of eighteen species of trees and shrubs known to science, of the plant family Sapindaceae.  s of 2013 fourteen species grow naturally in Australia and in neighbouring New Guinea only one endemic species is known to science.  Three species are known growing naturally in southern Africa, including two species endemic to South Africa and one species in South Africa, Swaziland and Mozambique.

Pennantia: Pennantia is the sole genus in the plant family Pennantiaceae.  In older classifications, it was placed in the family Icacinaceae.  Most authorities have recognised three or four species, depending on whether they recognised "Pennantia baylisiana" as a separate species from "Pennantia endlicheri".  Mabberley, however, has recognised only two species.  "Pennantia" species grow naturally in New Zealand, Norfolk Island, and eastern Australia.  In Australia, "P. cunninghamii" grows across a broad latitudinal natural range (nearly 3000 km ), from the south coast of New South Wales northwards through to north eastern Queensland.

Supporting paragraphs: Atalaya (plant) Vriesea
Answer: Atalaya