Question: Which genus of flowering plants contain more species, Hottonia or Annona?

Context paragraphs:
Opiliaceae: Opiliaceae is a family of flowering plants comprising 11 genera and 33 known species.  It consists of tropical woody plants.  Several genera contain parasitic species.  The biggest genus, in number of species and in stature of the individual plants, is "Agonandra", the only American genus.

Psorospermum: Psorospermum is a genus of flowering plants in the family Hypericaceae.  These plants contain xanthonoids.

Balanophoraceae: The Balanophoraceae (from the inflorescence which appears to be covered by barnacles) are a subtropical to tropical family of obligate parasitic flowering plants, notable for their unusual development and obscure affinities.  The family consist of 17 genera and around 44 known species.  The plants are normally found in moist inland forests growing on tree roots and have an aboveground inflorescence with the overall appearance of a fungus, composed of numerous minute flowers.  The inflorescences develop inside the tuberous underground part of the plant, before rupturing it and surfacing.  The plants are monoecious, or dioecious, and the fruits are indehiscent drupes or nuts.  The underground portion, which attaches itself to the host, looks like a tuber, and is not a proper root system.  The plants contain no chlorophyll.  "Balanophora" means "bearing an acorn" (shape of the female inflorescence).

Vismia: Vismia is a genus of flowering plants in the family Hypericaceae.  Like many members of the Hypericaceae, these plants contain xanthonoids.

Hottonia: Hottonia is a genus of aquatic flowering plants in the family Primulaceae.  It comprises two species:

Annona: Annona is a genus of flowering plants in the pawpaw/sugar apple family, Annonaceae.  It is the second largest genus in the family after "Guatteria", containing approximately 166 species of mostly neotropical and afrotropical trees and shrubs.

Melanthieae: Melanthieae is a tribe of flowering plants within the family Melanthiaceae.  Molecular phylogenetic studies in the 21st century have resulted in a large-scale reassignment of many of its species to different genera; in particular the genus "Zigadenus" (deathcamases) has been restricted to a single species, "Zigadenus glaberrimus".  Plants contain alkaloids, making them unpalatable to grazing animals; many are very poisonous to both animals and humans.

Mezerein: Mezerein is a toxic diterpene ester found in the sap of "Daphne mezereum" and related plants.  Plants of the genus "Euphorbiaceae" and "Thymelaeaceae" possess a wide variety of different phorbol esters, which share the capacity of mimicking diacylglycerol (DAG) and thus activating different isoforms of protein kinase C. Mezerein was first isolated in 1975.  It has antileukemic properties in mice, but it is also defined as a weak promoter of skin cancers in the same species.  All parts of the plants contain an acrid and irritant sap that contains mezerein, thought to be the principal poison.  The sap is especially prevalent in the bark and berries.

Xylothamia: Xylothamia, the desert goldenrods, is a genus of flowering plants in the daisy family, Asteraceae.  Until 2003, it was held to contain nine species of shrubs native to deserts of Mexico and the southwestern United States.  However, it seems to contain at least two groups.  Four species are related to "Gundlachia" and may be moved to that genus.  The relationships of the other five species is not quite as clear.  All nine species do belong in the subtribe Solidagininae.

Jasmine: Jasmine (taxonomic name Jasminum ) is a genus of shrubs and vines in the olive family (Oleaceae).  It contains around 200 species native to tropical and warm temperate regions of Eurasia, Australasia and Oceania.  Jasmines are widely cultivated for the characteristic fragrance of their flowers.  A number of unrelated plants contain the word "Jasmine" in their common names (see Other plants called "Jasmine").

Supporting paragraphs: Hottonia Annona
Answer: Annona