Question: Does Centaurium or Eucalyptus have more species?
Context: Eucalyptus camaldulensis, the river red gum, is a tree of the genus "Eucalyptus".  It is one of around 800 species within the genus.  It is a plantation species in many parts of the world, but is native to Australia, where it has the most widespread natural distribution of Eucalyptus in Australia, especially beside inland water courses.  Oddly, it is named for a private estate garden near the Camaldoli monastery near Naples (L'Hortus Camaldulensis di Napoli), from where the first specimen came to be described.  Material from this tree was used by Frederick Dehnhardt, Chief Gardener at the Botanic Gardens in Naples, to describe this species in 1832. Eucalyptus rubida, commonly known as Candlebark Gum or simply Candlebark, is a medium-sized eucalypt.  It occurs in south-eastern Australia and Tasmania, typically in open woodland around the lower slopes of the Great Dividing Range, but also in taller forests.  The subspecies "barbigerorum", found in localities in New South Wales, is listed as vulnerable.  Companion species include "Eucalyptus pauciflora", "Eucalyptus melliodora" and "Eucalyptus bridgesiana". Zeltnera is a genus of flowering plants in the gentian family.  It was erected in 2004 when the genus "Centaurium" (the centauries) was split.  Genetic analysis revealed that "Centaurium" was polyphyletic, made up of plants that could be grouped into four clades. Each became a genus.  "Centaurium" remained, but it is now limited to the Eurasian species.  The Mexican species now belong to genus "Gyrandra", and the Mediterranean and Australian plants are in genus "Schenkia".  The new name "Zeltnera" was given to this genus, which contains most of the North American centauries.  There are about 25 species. Centaurium (Centaury) is a genus of 20 species in the gentian family (Gentianaceae), tribe Chironieae, subtribe Chironiinae.  The genus was named after the centaur Chiron, famed in Greek mythology for his skill in medicinal herbs.  It is distributed across Europe and into Asia. Eucalyptus × tetragona is a hybrid species in the genus "Eucalyptus".  The valid taxonomic name "Eucalyptus tetragona" was previously used to describe the species now known as "Eucalyptus pleurocarpa", but the type specimen upon which the name was based turned out to be a hybrid with "E. extrica", so the later homonym "E. pleurocarpa" was adopted for the pure species, and "E." × "tetragona" for the hybrid.  The Noongar names for the tree are Talyerock or Tallerack. Corymbia is a genus of about 113 species of tree that were classified as "Eucalyptus" species until the mid-1990s.  It includes the bloodwoods, ghost gums and spotted gums.  The bloodwoods had been recognised as a distinct group within the large and diverse "Eucalyptus" genus since 1867.  Molecular research in the 1990s, however, showed that they, along with the rest of the Corymbia section, are more closely related to "Angophora" than to "Eucalyptus", and are probably best regarded as a separate genus.  All three genera—"Angophora", "Corymbia" and "Eucalyptus"—are closely related, often difficult to tell apart, and are still commonly and correctly referred to as "eucalypts".  Groups of naturalists and conservationists do not recognise the "Corymbia" genus and still categorise its species within "Eucalyptus". Eucalyptus L'Héritier 1789 is a diverse genus of flowering trees and shrubs (including a distinct group with a multiple-stem mallee growth habit) in the myrtle family, Myrtaceae.  Members of the genus dominate the tree flora of Australia, and include "Eucalyptus regnans", the tallest known flowering plant on Earth.  There are more than 700 species of eucalyptus and most are native to Australia; a very small number are found in adjacent areas of New Guinea and Indonesia.  One species, "Eucalyptus deglupta," ranges as far north as the Philippines.  Of the 15 species found outside Australia, just nine are exclusively non-Australian.  Species of eucalyptus are cultivated widely in the tropical and temperate world, including the Americas, Europe, Africa, the Mediterranean Basin, the Middle East, China, and the Indian subcontinent.  However, the range over which many eucalypts can be planted in the temperate zone is constrained by their limited cold tolerance.  Australia is covered by 92000000 ha of eucalypt forest, comprising three quarters of the area covered by native forest. Eucalyptus oil is the generic name for distilled oil from the leaf of "Eucalyptus", a genus of the plant family Myrtaceae native to Australia and cultivated worldwide.  Eucalyptus oil has a history of wide application, as a pharmaceutical, antiseptic, repellent, flavouring, fragrance and industrial uses.  The leaves of selected "Eucalyptus" species are steam distilled to extract eucalyptus oil. Cardiaspina densitexta is a bug species in the genus "Cardiaspina", found in Australia.  It is found on "Eucalyptus" species such as "Eucalyptus fasciculosa", "Eucalyptus diversifolia" and "Eucalyptus odorata".  This species protects itself in lerp. Leptocybe invasa, the blue gum chalcid wasp or eucalyptus gall wasp, is a chalcid wasp which is the only species in the monotypic genus "Leptocybe" in the subfamily Tetrastichinae, on the family Eulophidae.  It is a gall wasp which causes the formation of galls on a number of species of "Eucalyptus", it was described in 2004 after galls were found in river red gums ("Eucalyptus camaldulensis") in the Mediterranean and Middle East and has since been found to be a widespread species where its host trees are planted.  It is indigenous to Australia.
Answer: Eucalyptus