Claoxylon is a flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 in the spurge family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

, Euphorbiaceae

Euphorbiaceae

Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....

, comprising dioecious

Dioecious

Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...

 subshrub

Subshrub

A subshrub or dwarf shrub is a short woody plant. Prostrate shrub is a similar term.It is distinguished from a shrub by its ground-hugging stems and lower height, with overwintering perennial woody growth typically less than 10–20 cm tall, or by being only weakly woody and/or persisting...

s to small trees. The genus comprises about 80 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, distributed in paleotropical areas: Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

 through South

South Asia

South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

 and Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

, Malesia

Malesia

Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...

 to Melanesia

Melanesia

Melanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...

, Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

, and Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. Half of the species are in Malesia. According to a molecular phylogenetic study by Wurdack, Hoffmann & Chase (2005), Claoxylon is sister to Erythrococca

Erythrococca

Erythrococca is a plant genus of the family Euphorbiaceae. It comprises about 50 species, most of which are native to Africa, with 4 species in Southern Africa.-Synonyms:*Athroandra Pax & K.Hoffm.*Autrandra Pierre ex Prain...

(50 species, Africa), and together they form the top of a Hennigian
comb-like phylogeny.

The genera Erythrochilus Reinw. ex Blume (or Erythrochylus Reinw. ex Blume, an orthographic variant) and Quadrasia Elmer

Adolph Daniel Edward Elmer

Adolph Daniel Edward Elmer was an American botanist and plant collector.Elmer was born in 1870 in Van Dyne, Wisconsin, United States. He was educated at the Washington Agricultural College, and earned a M.Sc. from Stanford University in 1903. He made extensive plant collections in the Philippines...

is generally included into this genus.