Question: Between Platycarya and Houttuynia, which has more species within the genus?
Context: The Xanthomonadales are a bacterial order within the "Gammaproteobacteria".  They are one of the largest groups of bacterial phytopathogens, harbouring species such as "Xanthomonas citri", "Xanthomonas euvesicatoria", "Xanthomonas oryzae" and "Xylella fastidiosa".  These bacteria affect agriculturally important plants including tomatoes, bananas, citrus plants, rice, and coffee.  Many species within the order are also human pathogens.  Species within the "Stenotrophomonas" genus are multidrug resistant opportunistic pathogens that are responsible for nosocomial infections in immunodeficient patients. Binomial nomenclature (also called binominal nomenclature or binary nomenclature) is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages.  Such a name is called a binomial name (which may be shortened to just "binomial"), a binomen, binominal name or a scientific name; more informally it is also called a Latin name.  The first part of the name identifies the genus to which the species belongs; the second part identifies the species within the genus.  For example, humans belong to the genus "Homo" and within this genus to the species "Homo sapiens".  The "formal" introduction of this system of naming species is credited to Carl Linnaeus, effectively beginning with his work "Species Plantarum" in 1753.  But Gaspard Bauhin, in as early as 1623, had introduced in his book "Pinax theatri botanici" (English, "Illustrated exposition of plants") many names of genera that were later adopted by Linnaeus. A Regional Red List (RRL) is a report of the threatened status of species within a certain country or region.  It is based on the IUCN Red List of Threatened Species, an inventory of the conservation status of species on a global scale.  Regional Red Lists assess the risk of extinction to species within a political management unit and therefore may feed directly into national and regional planning.  This project is coordinated by the Zoological Society of London (ZSL), the World Conservation Union (IUCN) and partners in national governments, universities and organizations throughout the world. Paederus is a genus of small beetles of the family Staphylinidae ("rove beetles").  With 622 valid species assigned by 1987 to the subtribe Paederina ("Paederus" and its close allies), and with all but 148 within "Paederus" itself, the genus is large.  Due to toxins in the hemolymph of some species within this genus, it has given its name to paederus dermatitis, a characteristic skin irritation that occurs if one of the insects is crushed against skin.  That name, Paederus dermatitis, is a poor choice because, decades earlier, the affliction had been called dermatitis linearis, a name that works in all languages, not just English, because of its Latin origin; the name Paederus dermatitis is also inappropriate because it has shown to be caused by (a) only a few species of the genus Paederus, but (b) also a few species that belong to closely related genera (that are not "Paederus") within the subtribe Paederina.  A scholarly paper in 2002 suggested that a "Paederus" species could have been responsible for some of the ten Plagues of Egypt described in the Bible's Book of Exodus. Besla vaga is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.  The species is one of twelve known species within the Besla genus of gastropods.  The species is one of three species within the Besla genus to have a binomial name accepted by Laws, C. R. in 1941, with the exception of the other two being Besla rossiana and Besla waitangiensis. Houttuynia cordata (; Japanese: "dokudami" 蕺草, literally "poison blocking plant"; Vietnamese: "giấp cá" ; Lao: "pak kao tong" ຜັກຄາວທອງ; Thai: "phakkaawtong" ผักคาวตอง, ผักคาวทอง, พลูคาว; Korean: 약모밀, 어성초 ).  In Manipur, it is known as "toningkok", in Tangkhul as "Ngayungna" in Hmar as "Aithang", in Meghalaya it is known as Jamyrdoh, in Chakma as Mosondori, in Mizo as "Uithinthang", and in thadou as "Aithanglou", "Hrama" in Poula.  In Rongmei, it is called as "Gancmaluh".  In English, it is known as fish mint, fish leaf, lizard tail, chameleon plant, heartleaf, fishwort, and bishop's weed.  It is one of two species in the genus "Houttuynia" (the other being "H. emeiensis"), a flowering plant native to Japan, Korea, southern China, and Southeast Asia, where it grows in moist, shady places. Pseudophryne is a genus of small Myobatrachid frogs. All of these frogs are small terrestrial frogs, and as such, most species are commonly called toadlets ("pseudo-" meaning deceptive, "phryne" meaning toad).  The genus comprises thirteen species, ten from eastern Australia, and three from Western Australia.  Species within the "Pseudophryne" genus lay their eggs on moist ground.  The tadpoles develop within the eggs, and once they reach hatching size, will become dormant.  Once sufficient rain occurs to flush the eggs into a creek or river, the eggs will hatch and release tadpoles into the water.  Many of the species within this genus have the ability to form hybrids. Houttuynia is a genus of two species in the Saururaceae native to Southeast Asia.  One species, "H. cordata", is widely cultivated as a culinary herb.  The genus was originally described in 1783 by Carl Peter Thunberg when he formally described "H. cordata" as the only species.  It remained a monotypic genus until 2001 when Zheng Yin Zhu and Shi Liang Zhang discovered and described a second species native to China, "H. emeiensis". Besla waitangiensis is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.  The species is one of twelve known species within the Besla genus of gastropods.  The species is one of three species within the Besla genus to have a binomial name accepted by Laws, C. R. in 1941, with the exception of the other two being Besla rossiana and Besla vaga. Platycarya is a genus of flowering plants in the family Juglandaceae, usually treated as comprising a single species Platycarya strobilacea, though one to two additional species are accepted by some authors.  It is native to eastern Asia in China, Korea, and Japan.
Answer: Houttuynia