Question: Which genus has more known species, Eucommia or Rhoicissus?
Context: Eucommia montana is an extinct species of flowering plant in the family Eucommiaceae.  "E. montana" is known from fossil fruits found in Eocene deposits of the northwestern United States southeastern British Columbia south to Oregon and east to Montana and Colorado.  "E. montana" is one of five described fossil species from North America assigned to the modern genus "Eucommia".  The other species are "E. constans", "E. eocenica", "E. jeffersonensis", and "E. rowlandii". Moniezia a genus of tapeworms that are parasitic in mammals, including sheep, goat and cattle.  It comprises four known species such as "M. expansa", "M. benedeni", "M. autumnalis" and "M. baeri". " M. expansa" is the most well known species within the genus because of its high prevalence.  Members of the genus are among the largest cestodes reaching up to 10 m in length.  They inhabit the small intestine of mammalian host.  Their life cycle is indirect requiring intermediate host, which are oribatid mites.  They are characterized by the presence of interproglottid glands. Eucommia jeffersonensis is an extinct species of flowering plant in the family Eucommiaceae.  It is known from a fossil fruit found in latest Eocene deposits of Oregon, United States.  "E. jeffersonensis" is one of five described fossil species from North America assigned to the modern genus "Eucommia".  The other species are "E. constans", "E. eocenica", "E. montana", and "E. rolandii". Eucommia rolandii is an extinct species of flowering plant in the family Eucommiaceae.  "E. jeffersonensis" is known from a fossil leaves found in Middle Eocene deposits of British Columbia, Canada and Mississippi, United States.  "E. rolandii" is one of five described fossil species from North America assigned to the modern genus "Eucommia".  The other species are "E. constans", "E. eocenica", "E. jeffersonensis", and "E. montana". Eucommia is a genus of small trees now native to China, with a fossil record that shows a much wider distribution.  The single living species, "Eucommia ulmoides", is near threatened in the wild, but is widely cultivated in China for its bark, and is highly valued in herbology such as traditional Chinese medicine. Rhoicissus is an Afrotropical plant genus in the grape family Vitaceae and Vitoideae subfamily.  There are between 9 and 22 accepted species. Arcobacter is a genus of Gram-negative, spiral-shaped bacteria in the epsilonproteobacteria class.  It shows an unusually wide range of habitats, and some species can be human and animal pathogens.  Species of the genus "Arcobacter" are found in both animal and environmental sources, making it unique among the epsilonproteobacteria.  This genus currently consists of five species: "A. butzleri", "A. cryaerophilus", "A. skirrowii", "A. nitrofigilis", and "A. sulfidicus", although several other potential novel species have recently been described from varying environments.  Three of these five known species are pathogenic.  Members of this genus were first isolated in 1977 from aborted bovine fetuses.  They are aerotolerant, "Campylobacter"-like organisms, previously classified as "Campylobacter".  The "Arcobacter" genus, in fact, was created as recently as 1992.  Although they are similar to this other genus, "Arcobacter" species can grow at lower temperatures than "Campylobacter", as well as in the air, which "Campylobacter" cannot. Termitaphididae, occasionally called termite bugs, is a small tropicopolitan family of true bugs placed in the superfamily Aradoidea.  Typically members of Termitaphididae are small, being an average of 2 mm -4 mm , and flattened with laminae extending out from each body segment giving a round scale like appearance.  Currently the family contains two genera and twelve known species.  Members of Termitaphididae are inquilines lodging in the nests of host species of termite families Termitidae and Rhinotermitidae.  Though considered a separate family in Aradoidea it has been suggested by Drs David Grimaldi and Michael Engel in 2008 that Termataphididae may in fact be highly derived members of Aradidae.  Of the thirteen known species one "Termitaphis circumvallata" belongs to the monotypic genus "Termitaphis" and four of the remaining eleven species in "Termitaradus" are extinct, having only been found in amber.  The living species are found worldwide in the tropical regions of Central and South America, Africa, Asia, and Australia. Eucommia constans is an extinct species of flowering plant in the family Eucommiaceae. " Eucommia" is a genus of small trees now native to China, with a fossil record that shows a much wider distribution.  "E. constans" is known from fossil fruits found in Miocene to Pleistocene deposits of east-central Mexico.  "E. constans" is one of five described fossil species from North America assigned to the modern genus "Eucommia".  The other species are "E. eocenica", "E. jeffersonensis", "E. montana", and "E. rowlandii". Eucommia eocenica is an extinct species of flowering plant in the family Eucommiaceae.  "E. eocenica" is known from fossil fruits found in the middle Eocene Claiborne Formation deposits of the southeastern United States.  "E. eocenica" is one of five described fossil species from North America assigned to the modern genus "Eucommia".  The other species are "E. constans", "E. jeffersonensis", "E. montana", and "E. rowlandii".
Answer: Rhoicissus