Question: Which has more species, Cananga or Olea?
Context: Olea capensis, also known by the common name black ironwood, is an African tree species belonging to the Olive family (Oleaceae).  It is widespread in Sub-Saharan Africa from the east in Somalia, Ethiopia and Sudan, south to the tip of South Africa, and west to Cameroon, Sierra Leone and the Islands of the Gulf of Guinea, as well as Madagascar and the Comoros.  It occurs in bush, littoral scrub and evergreen forest. Olea is a genus of about 40 species in the family Oleaceae, native to warm temperate and tropical regions of southern Europe, Africa, southern Asia, and Australasia.  They are evergreen trees and shrubs, with small, opposite, entire leaves.  The fruit is a drupe.  Leaves of "Olea" contain trichosclereids. Barriopsis iraniana is an endophytic fungus first found on "Citrus", "Mangifera" and "Olea" species in Iran. The olive pigeons are four pigeon species, named for their association with olive ("Olea") species.  They have a maroon tone to the speckled plumage, and inhabit cool, montane forests of Africa and its associated islands. Cananga is a small genus of trees in the family Annonaceae.  One of its species, "Cananga odorata", is important as the source of the perfume ylang-ylang.  Two species are recognized: Noronhia emarginata (Madagascar olive; syn.  "Olea emarginata" Lam.)  is a species of "Noronhia" native to Madagascar, now naturalized on Mauritius, Réunion and Bermuda. Olea oleaster, the wild-olive, has been considered by various botanists a valid species and a subspecies of the cultivated olive tree, "Olea europea", which is a tree of multiple origins that was domesticated, it now appears, at various places during the fourth and third millennia BCE, in selections drawn from varying local populations.  The wild-olive (Ancient Greek "kotinos"), which ancient Greeks distinguished from the cultivated olive tree (Ancient Greek ἐλάα), was used to fashion the olive wreath awarded victors at the ancient Olympic games.  The ancient and sacred wild-olive tree of Olympia stood near the Temple of Zeus, patron of the games. Akbesia is a genus of moths in the Sphingidae family, containing only one species, the Pistacia hawkmoth, Akbesia davidi, which is known from southern Turkey, northern Syria, northern Israel, western Jordan, south-eastern Turkey, north-eastern Iraq, south-eastern Georgia, northern Iran, eastern Afghanistan and Iranian Beluchistan.  It may also occur across Azerbaijan, the Alborz Mountains of northern Iran, the Zagros Mountains of western and southern Iran, and northern Afghanistan.  It often occurs in large numbers at certain sites in rocky, hilly areas supporting scattered trees and shrubs of "Quercus", "Olea", "Ceratonia" and "Pistacia". The olive, known by the botanical name Olea europaea, meaning "European olive", is a species of small tree in the family Oleaceae, found in the Mediterranean Basin from Portugal to the Levant, the Arabian Peninsula, and southern Asia as far east as China, as well as the Canary Islands and Réunion.  The species is cultivated in many places and considered naturalized in all the countries of the Mediterranean coast, as well as in Argentina, Saudi Arabia, Java, Norfolk Island, California, and Bermuda. Olea hochstetteri (East African olive, black ironwood) is a species of tree of the Oleaceae family, often considered a subspecies of Olea capensis.  Like the related species Olea welwitschii, it grows in sandy desert regions of Kenya, Tanzania and Uganda.  It is an inconspicuous plant that does not attain great height, in contrast to O. welwitschii which can attain a height of 25m.
Answer: Olea