''Duroia hirsuta'' is a

myrmecophyte Myrmecophytes (; literally "ant-plant") are plants that live in a mutualistic association with a colony of ants. There are over 100 different genera of myrmecophytes. These plants possess structural adaptations in the form of domatia where ants ...

tree species from the

Amazon Forest The Amazon rainforest, also called the Amazon jungle or Amazonia, is a Tropical and subtropical moist broadleaf forests, moist broadleaf tropical rainforest in the Amazon biome that covers most of the Amazon basin of South America. This basin ...

. It is one of some 37 species of '' Duroia,'' which are shrubs or canopy trees in the family

Rubiaceae Rubiaceae () is a family (biology), family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with Petiole ( ...

, favoring ants ( myrmecophilous), and occurring in

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

as far north as

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

, the

Guiana Shield The Guiana Shield (; ; ; ) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on ...

, the Brazilian Atlantic coast and planalto.

Plant Interactions

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'' have yielded a strong plant growth inhibitor plumericin, a

tetracyclic Tetracyclics are cyclic compound, cyclic chemical compounds that contain four fused ring (chemistry), rings of atoms, for example, Tröger's base. Some tricyclic compounds having three fused and one tethered ring (connected to main nucleus by ...

iridoid Iridoids are a type of monoterpenoids in the general form of cyclopentanopyran, found in a wide variety of plants and some animals. They are biosynthetically derived from 8-oxogeranial. Iridoids are typically found in plants as glycosides, mo ...

lactone Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresp ...

, and duroin, another iridoid lactone. This process, common amongst plants, is termed

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

. In the case of ''Duroia hirsuta'', the chemical inhibitor is aided by the Lemon Ant, a 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 (), systematically named methanoic acid, is the simplest carboxylic acid. It has the chemical formula HCOOH and structure . This acid is an important intermediate in chemical synthesis and occurs naturally, most notably in some an ...

, and defending against herbivores - other ant species such as '' Azteca'' spp. and ''Allomerus octoarticulatus demerarae'' exhibit the same mutualism. The area around this

understory In forestry and ecology, understory (American English), or understorey (English in the Commonwealth of Nations, Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the Canopy (biology), forest ca ...

tree is often devoid of all other plant types, leading to the local name "

Devil's garden In myrmecology and forest ecology, a devil's garden (Kichwa language, Kichwa: ''Supay chakra''Frederickson, M. E., & Gordon, D. (2007). The devil to pay: the cost of mutualism with ''Myrmelachista schumanni'' ants in 'devil's gardens' is increased ...

." The cost to the host plant for this protection is considerable, since the resident ants subject the tree to increased leaf cutting. Trees that grow outside the cleared area often have the living tissues of their trunks excavated and

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or war ...

ed for ant accommodation. The ants involved in the relationship specifically aid the plant in defense against herbivores, supplying nutrients, and pollination.Baez, Et al. 2016. ''Ant Mutualism Increases Long-Term Growth and Survival of a Common Amazonian Tree,'' Museo de Colecciones Biológicas, Universidad Técnica Particular de Loja, Loja, Ecuador, Et alibi.Frederickson, Gordon. 2009. ''The intertwined population biology of two Amazonian myrmecophytes and their symbiotic ants,'' Stanford, California: Department of Biological Sciences, Stanford University. Their mutualism is strengthened by the positive size-dependent growth each gains from the relationship.Frederickson. 2006. ''THE INTERTWINED POPULATION BIOLOGY OF SYMBIOTIC ANTS AND PLANTS IN THE AMAZON'', Stanford, California: Stanford University. One specific type of ant, the M. Schummanni are notorious for supporting the largest plant sizes and growth rates.Frederickson. 2005. ''Ant species confer different partner benefits on two neotropical myrmecophytes,'' Oecologia, Plant Animal Interactions.

Environment Conditions

The environmental conditions that influence the fitness of the species also has an impact on the amount of rewards reaped by the ants involved in the mutualistic relationship with the plant. The effectiveness of ants is greater in conditions where nutrients are scarce as opposed to environments with favorable conditions for the plant. Size of the plant is a great indicator of fitness and is often measured by the amount of

Domatia A domatium (plural: domatia, from the Latin "domus", meaning home) is a tiny chamber that houses arthropods, produced by a plant. Ideally domatia differ from galls in that they are produced by the plant rather than being induced by their inhabi ...

present. Ants can aid the plant in receiving more sunlight by clearing the canopies above the plant and limit competition from other nearby plants.

References

External links

New York Botanical Garden
{{Taxonbar, from=Q1955787 Cordiereae Plants described in 1888