Duroia is a genus of some 37 species of shrubs or canopy trees in the family Rubiaceae

Rubiaceae

The Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...

, favouring ants (myrmecophilous), and occurring in Central America

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 as far north as Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, the Amazon Basin

Amazon Basin

The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...

, the Guiana Shield, the Brazilian Atlantic coast and planalto

Planalto

-Buildings:* Palácio do Planalto, Brasília, the official seat of the President of Brazil.** The staff and offices of the Executive branch of the Brazilian Government, by metonymy-Places:*Planalto, Bahia *Planalto, Paraná *Planalto, Rio Grande do Sul...

.

A number of Duroia species, and possibly all, are capable of biochemical interactions inhibiting the growth of neighbouring plants. Analysis of root extracts from Duroia hirsuta

Duroia hirsuta

Duroia hirsuta is a myrmecophyte tree species from the Amazon Forest. It is one of some 37 species of Duroia which are shrubs or canopy trees in the family Rubiaceae, favouring ants , and occurring in Central America as far north as Mexico, the Amazon Basin, the Guiana Shield, the Brazilian...

have yielded a strong plant growth inhibitor plumericin, a tetracyclic

Tetracyclic

Tetracyclic may refer to* any of a number of cyclic compounds containing four rings. They have various pharmaceutical uses; see Tetracyclic drug group.* cyclic flowers constructed of four whorls....

 iridoid

Iridoid

Iridoids are a class of secondary metabolites found in a wide variety of plants and in some animals. They are monoterpenes biosynthesized from isoprene and they are often intermediates in the biosynthesis of alkaloids. Chemically, the iridoids usually consist of a cyclopentane ring fused to a...

 lactone

Lactone

In chemistry, a lactone is a cyclic ester which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule...

. This process, common amongst plants, is termed allelopathy

Allelopathy

Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms...

. In the case of Duroia hirsuta, the chemical inhibitor is aided by the leafcutter ant Myrmelachista schumanni

Myrmelachista schumanni

Myrmelachista schumanni, also known as the lemon ant, is a species of ant that is notable for the creation of Devil's garden. Using its own herbicide, it is able to shape its surroundings....

resident on and in the tree, and playing an active role in suppressing and destroying plant growth in the vicinity of their host by injecting and spraying formic acid

Formic acid

Formic acid is the simplest carboxylic acid. Its chemical formula is HCOOH or HCO2H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant, formica, referring to its early...

. The area around the understory

Understory

Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...

 species Duroia hirsuta is often devoid of all other plant types, leading to the local name 'Devil's garden

Devil's garden

This should not be confused with the Devil's gardensIn myrmecology and forest ecology, a devil's garden is a large stand of trees in the Amazon Rainforest consisting almost exclusively of a single species, Duroia hirsuta...

'. The cost to the host plant for this protection is considerable, since the resident ants subject the tree to increased leaf cutting.

Species

Duroia contains the following species:

• Duroia amapana Steyerm.
• D. aquatica (Aubl.) Bremek.
• D. bolivarensis Steyerm.
• D. costaricensis Standl.
• D. duckei Huber
• D. eriopila L.f.
• D. fusifera Spruce ex K.Schum.
• D. genipoides Spruce ex K.Schum.
• D. gransabanensis Steyerm.
• D. hirsuta (Poepp.) K.Schum.
• D. hirsutissima Steyerm.
• D. kotchubioides Steyerm.
• D. laevis Devia Perss. & C.M.Taylor
• D. longiflora Ducke
• D. longifolia (Poepp.) K.Schum.
• D. macrophylla Huber
• D. maguirei Steyerm.
• D. martiniana (Miers) Bremek.
• D. melinonii Standl.
• D. merumensis Steyerm.
• D. micrantha (Ladbr.) Zarucchi & J.H.Kirkbr.
• D. nitida Steyerm.
• D. palustris Ducke
• D. paraensis Ducke
• D. paruensis Steyerm.
• D. petiolaris Spruce ex K.Schum.
• D. plicata Benoist
• D. prancei Steyerm.
• D. retrorsipila Steyerm.
• D. saccifera (Mart. ex Schult. & Schult.f.) K.Schum.
• D. sancti-ciprianii Devia Perss. & C.M.Taylor
• D. soejartoi D.R.Simpson
• D. steinbachii Standl.
• D. strigosa Steyerm.
• D. trichocarpa Standl.
• D. triflora Ducke
• D. velutina Hook.f. ex K.Schum.