Question: Which genus of plant is native to more countries, Agonis or Ceraria?

Context paragraphs:
Taxandria angustifolia: Taxandria angustifolia is a species of tree that grows on the south coast of Western Australia.  This plant was previously classified as "Agonis angustifolia" but is now part of the "Taxandria" genus.

Taxandria parviceps: Taxandria parviceps, commonly known as tea tree, is a shrub species that grows on the south west coast of Western Australia.  This plant was previously classified as "Agonis parviceps" but is now part of the "Taxandria" genus.

Agonis: Agonis is a genus in the plant family Myrtaceae.  All are endemic to Western Australia, growing near the coast in the south west.

Taxandria linearifolia: Taxandria linearifolia, also known as the swamp peppermint or the coarse teatree, is a small tree or shrub species that grows along south west coastal areas of Western Australia.  This plant was previously classified as "Agonis linearifolia" but is now part of the "Taxandria" genus.

Taxandria floribunda: Taxandria floribunda is a small tree or shrub species that is endemic to an area in southern Western Australia.  This plant was previously classified as "Agonis floribunda" but is now part of the "Taxandria" genus.

Weed: A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place".  Examples commonly are plants unwanted in human-controlled settings, such as farm fields, gardens, lawns, and parks. Taxonomically, the term "weed" has no botanical significance, because a plant that is a weed in one context is "not" a weed when growing in a situation where it "is" in fact wanted, and where one species of plant is a valuable crop plant, another species in the same genus might be a serious weed, such as a wild bramble growing among cultivated loganberries.  Many plants that people widely regard as weeds also are intentionally grown in gardens and other cultivated settings, in which case they are sometimes called beneficial weeds.  The term "weed" also is applied to any plant that grows or reproduces aggressively, or is invasive outside its native habitat.  More broadly "weed" occasionally is applied pejoratively to species outside the plant kingdom, species that can survive in diverse environments and reproduce quickly; in this sense it has even been applied to humans.

Taxandria marginata: Taxandria marginata is a species of tree that grows in the south west corner of Western Australia.  This plant was previously classified as "Agonis marginata" but was reclassified by Wheeler and Marchant into the new genus "Taxandria" in a 2007 revision.

Taxandria spathulata: Taxandria spathulata is a shrub species that grows along the southern coast of Western Australia.  This plant was previously classified as "Agonis spathulata" but is now part of the "Taxandria" genus.

Ceraria: Ceraria is a genus of succulent shrubs, native to South Africa and Namibia.

Taxandria juniperina: Taxandria juniperina commonly known as wattie, native cedar, Warren River cedar or juniper myrtle is a species of tree that grows in the south west corner of Western Australia.  This plant was previously classified as "Agonis juniperina" but is now part of the "Taxandria" genus.

Supporting paragraphs: Agonis Ceraria
Answer: Ceraria