''Glossopetalon'' is a small genus of

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s in the plant family Crossosomataceae. These plants are sometimes called greasebushes. They are native to Mexico and the western United States, where they can be found on dry mountain slopes. These are usually small shrubs, although ''

Glossopetalon spinescens ''Glossopetalon spinescens'', syn. ''Forsellesia spinescens'', is a species of flowering shrub in the family Crossosomataceae known by the common names greasebush, spiny greasebush, Nevada greasewood and spring greasebush. It is native to Me ...

'' can reach up to three metres in favoured locations. They have thorny, tangling branches and white flowers with petals that are easily shed, giving them an untidy appearance. ''G. pungens'' is not thorny, and is a vertically prostrate subshrub which is usually found as a small tangled mat of stems hugging sheer cliffs. ''Glossopetalon'' was described by the American botanist

Asa Gray Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botanist of the 19th century. His ''Darwiniana'' was considered an important explanation of how religion and science were not necessarily mutually excl ...

in 1853. Gray first placed his new genus in the Celastraceae family, but twenty years later thought it was most closely related to ''

Staphylea ''Staphylea'', called bladdernuts, is a small genus of 10 or 11 species of flowering plants in the family Staphyleaceae, native to temperate regions of the Northern Hemisphere. The highest species diversity is in China, where four species occur. ...

'', then in the

Sapindaceae The Sapindaceae are a family of flowering plants in the order Sapindales known as the soapberry family. It contains 138 genera and 1858 accepted species. Examples include horse chestnut, maples, ackee and lychee. The Sapindaceae occur in tempera ...

, and a few authors accepted this classification at the time (1880). Within two decades (1897), however, this genus was placed back in the Celastraceae again, where it remained until 1978. It was placed in Crossosomataceae by Thorne and Scogin at that time, as the third genus known in this small family. Edward Lee Greene noticed that the generic name ''Glossopetalon'' was extremely similar to the name ''Glossopetalum'', which had been coined by

Johann Christian Daniel von Schreber Johann Christian Daniel von Schreber (17 January 1739 in Weißensee, Thuringia – 10 December 1810 in Erlangen), often styled J.C.D. von Schreber, was a German naturalist. Career He was appointed professor of'' materia medica'' at the Univers ...

in 1789 for another genus also placed in the Celastraceae at the time (''

Goupia ''Goupia'' is a neotropical genus of flowering plants and the sole genus included in the family Goupiaceae. There are three species, all found in tropical northern South America.Lacostea, J. F., & Alexandre, D. Y. (1991). Le goupi (Goupia glabra ...

''), and considered ''Glossopetalon'' to be a homonym of that name, so in 1893 Greene officially renamed the genus ''Forsellesia''. It continues to be the subject of a dispute about whether its proper name is ''Forsellesia'' or ''Glossopetalon''.Victoria Sosa. "Crossosomataceae" In: Klaus Kubitzki (ed.) ''The Families and Genera of Vascular Plants'' vol.IX. Springer-Verlag: Berlin, Heidelberg (2007). The type species is ''G. spinescens''. In 1942 eight species were recognised. Of those, ''G. meionandrum'', ''G. nevadense'', ''G. planitierum'' and ''G. stipuliferum'' were all placed in synonymy with ''G. spinescens'' in 1988. Thus, the remaining species included in 2015 were: *''

Glossopetalon clokeyi ''Glossopetalon clokeyi'', known as Clokey's greasebush is a species of flowering plant native to western North America. Distribution and habitat Clokey's greasebush is a rare species, endemic to the Spring Mountains The Spring Mountains a ...

'' - Clokey's greasebush *''

Glossopetalon pungens ''Glossopetalon'' is a small genus of shrubs in the plant family Crossosomataceae. These plants are sometimes called greasebushes. They are native to Mexico and the western United States, where they can be found on dry mountain slopes. These ar ...

'' - dwarf greasebush *''

'' - spiny greasebush *''

Glossopetalon texense ''Glossopetalon'' is a small genus of shrubs in the plant family Crossosomataceae. These plants are sometimes called greasebushes. They are native to Mexico and the western United States, where they can be found on dry mountain slopes. These are ...

'' - Texas greasebush In 2021 a phylogenetic study found that ''G. clokeyi'' and ''G. texense'' were not distinct as species, and belonged within ''G. spinescens'' as well. The species prefer dry limestone substrates.

References

External links

Jepson Manual Treatment
Crossosomataceae Rosid genera {{rosid-stub