Pentagonia is a genus of over 40 species of plants in the family Rubiaceae. Pentagonia species are native to Central America and northern South America, and grow in moist tropical forests below 900m. The genus was first described by George Bentham in 1845. The genus is noteworthy for its opposite pairs of huge leaves in a variety of shapes including entire, shallowly or deeply lobed, and even pinnate. These leaves can, in the case of a recently discovered species, be up to four feet (1.2 meters) long not including the six inch (15 cm) petiole, and up to 2.5 feet (76 centimeters) in width. Species , Plants of the World Online accepted the following species: Pentagonia amazonica (Ducke) L.Andersson & Rova Pentagonia angustifolia C.M.Taylor Pentagonia australis C.M.Taylor & Janovec Pentagonia baumannii Cornejo & Rova Pentagonia bocataurensis Dwyer Pentagonia bonifaziana Cornejo Pentagonia breviloba L.Andersson & Rova Pentagonia carniflora Cornejo & Rova Pentagonia chocoensis Cornejo Pentagonia clementinensis Cornejo Pentagonia costaricensis (Standl.) W.C.Burger & C.M.Taylor Pentagonia donnell-smithii (Standl.) Standl. Pentagonia dwyeriana C.M.Taylor Pentagonia gambagam Hammel & Aguilar Pentagonia gigantifolia Ducke Pentagonia gomez-lauritoi Hammel Pentagonia grandiflora Standl. Pentagonia gymnopoda (Standl.) Standl. Pentagonia hirsuta Standl. Pentagonia imparipinnata Cornejo Pentagonia involucrata C.M.Taylor Pentagonia lanciloba Cornejo Pentagonia lobata C.M.Taylor Pentagonia macrophylla Benth., syn. Pentagonia orthoneura Pentagonia magnifica K.Krause Pentagonia microcarpa L.Andersson & Rova Pentagonia nuciformis Dwyer Pentagonia osaensis C.M.Taylor Pentagonia osapinnata Aguilar, N.Zamora & Hammel Pentagonia pachiteana Cornejo Pentagonia parvifolia Steyerm. Pentagonia pinnatifida Seem. Pentagonia rubriflora D.R.Simpson Pentagonia sanblasensis C.M.Taylor Pentagonia spathicalyx K.Schum., syn. Pentagonia peruviana Pentagonia subauriculata Standl. Pentagonia subsessilis L.Andersson & Rova Pentagonia tapacula Cornejo Pentagonia tinajita Seem. Pentagonia villosula L.Andersson & Rova Pentagonia wendlandii Hook.f. Pentagonia williamsii Standl. Pentagonia wurdackii Steyerm. References Rubiaceae genera