''Enterolobium cyclocarpum'', commonly known as conacaste, guanacaste, caro caro, devil's ear tree, monkey-ear tree, or elephant-ear tree, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

tree in the family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

, that is native to

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

regions of the Americas, from central Mexico south to northern Brazil (

Roraima Roraima ( ) is one of the 26 states of Brazil. Located in the country's North Region, it is the northernmost and most geographically and logistically isolated state in Brazil. It is bordered by the state of Pará to the southeast, Amazonas t ...

) and Venezuela. It is known for its large proportions, expansive, often spherical crown, and curiously shaped seedpods. The abundance of this tree, especially in

Guanacaste Province Guanacaste () is a Provinces of Costa Rica, province of Costa Rica located in the northwestern region of the country, along the coast of the Pacific Ocean. It is bordered by Nicaragua to the north, Alajuela Province to the east, and Puntarenas Pro ...

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

, where it is prized for the shady relief it provides from the intense sun, coupled with its immensity, have made it a widely recognized species. It is the

national tree This is a list of countries that have officially designated one or more trees as their national trees. Most species in the list are officially designated. Some species hold only an "unofficial" status. Additionally, the list includes trees that we ...

of Costa Rica. In North America, it is often called elephant-ear tree, due to the shape of the seedpods. Other common names include devil's ear and earpod tree, ''parota'', and ''orejón'' (Spanish) orhuanacaxtle'' (

Nahuatl Nahuatl ( ; ), Aztec, or Mexicano is a language or, by some definitions, a group of languages of the Uto-Aztecan language family. Varieties of Nahuatl are spoken by about Nahuas, most of whom live mainly in Central Mexico and have smaller popul ...

). In

El Salvador El Salvador, officially the Republic of El Salvador, is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by the Pacific Ocean. El Salvador's capital and largest city is S ...

, it is known as ''conacaste''. In the Yucatán peninsula, it is known by the Mayan name, ''pich.'' In Panama, it is known as a ''corotú''.

Description

Source: The guanacaste is a medium-sized to large

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

, growing to tall, with a trunk up to in diameter. Unusual in a tree of these proportions, buttresses are completely lacking. The

bark Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...

is light gray, with prominent dark reddish-brown, vertical fissures. In young trees, these fissures are closer together. and their confluence lends a characteristic reddish hue to the bark of guanacaste saplings. Older specimens often present broken, chipped, or scarred bark. The crown is broad and widely spreading. The height at which branches first occur along the trunk – as well as the overall tree shape – vary considerably among individuals and are habitat-dependent characteristics. Frequently, guanacaste trees grow as single specimens in a sunny pasture. Under these conditions, massive, extended, horizontal limbs emerge low on the boles, forming giant, hemispherical, widely spreading crowns. In the forest (where competition for light is intense), trees tend to become taller, and branching occurs at a higher level. Tree forms then become somewhat narrower, though crowns are still rounded, and hemispherical shapes are maintained by those that have reached the canopy. The alternate

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are bipinnate compound, long and broad with a petiole bearing four to 15 pairs of pinnae, each pinna with 40–70 leaflets; the leaflets are slender, oblong, long by wide. Near its base, the twiggy petiole bears a small, raised, oval gland. The leaves are confined to the outer shell of the crown, yet they are plentiful enough to make it moderately dense and green. The guanacaste is

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

, or briefly

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

for 1–2 months during the

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The t ...

. Most foliage is shed in December, at the start of the dry season. In late February, a growth surge is initiated that re-establishes a fresh, thick crown by April. Concurrent with the leaves' renewal is the appearance of globular

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s () in the axils of the new leaves. Supported by a long pedestal (), each spherical white head – composed of about 50 individual flowers – sports thousands of thin, filamentous stamens as its major feature. The blossoms themselves each consist of about 20 stamens and a single pistil, bound together at the base by a short, green, tubular corolla and an even shorter calyx, just long altogether. Guanacaste flowers are very fragrant, and during intense flowering periods, their odor permeates the air for many meters in all directions. In Manuel Antonio National Park near Quepos, Costa Rica, flowering lasts from late February to early April. Surprisingly, no obvious fruiting activity immediately follows the decline of the blossom. Rather, 9–10 months pass before small, green pods first appear high in the crown by December. They reach full size by February and finally begin to ripen in March – a full year after flowering has ceased. Fruit ripening lasts from March to April, as the green pods turn brown in the guanacaste crown and are slowly shed. Vigorous trees produce large crops on a nearly annual basis. In June, guanacaste seedlings can already be seen, germinating in the moist soil of the early rainy season. Guanacaste fruits are large ( diameter), glossy dark brown

indehiscent Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part. Structures that ...

and spirally organized pods, shaped like orbicular disks. Their shape suggests the usual

Mimosoideae The Mimosoideae are a traditional subfamily of trees, herbs, lianas, and shrubs in the pea family (Fabaceae) that mostly grow in tropical and subtropical climates. They are typically characterized by having radially symmetric flowers, with petal ...

fruit – a long, narrow, flattened pod – taken and wound around an axis perpendicular to its plane. Made of thick, soft tissue with a leathery feel, the pods contain eight to 20 radially arranged seeds, long, wide, and thick and weighing about 1 g. Guanacaste seeds are brown and marked with a conspicuous light brown or orange ring. They are very hard, resembling small stones rather than tree seeds in their strength and durability. For germination to occur, the hard seed coat must be broken to enable water to reach the embryo. Otherwise, the seeds lie dormant indefinitely. The ardillo ('' Cojoba arborea'') and the iguano ('' Dilodendron costaricense'') possess similar bipinnate leaves with extra-fine leaflets. Though of equally impressive stature, these two trees can be distinguished readily from the guanacaste; the ardillo has tan-colored, heavily wrinkled, and rough bark – nothing like the guanacaste's unmistakably gray and vertically cracked cortex. The iguano's leaflets are serrated (an unusual feature in a bipinnate tree), while those of the guanacaste are entire.

Ecology

Guanacaste trees appear to delay the onset of fruit development—some 9 months—so that seed maturation coincides with the start of the rainy season. This adaptive behavior presumably is an adaptation to give germinating seedlings as much time as possible to establish root systems before the start of the next dry season. Both the jatobá (''Hymenaea courbaril'') and the cenizaro (''

Albizia saman ''Albizia'' is a genus of more than 160 species of mostly fast-growing Subtropics, subtropical and Tropics, tropical trees and shrubs in the subfamily Mimosoideae of the family (biology), family Fabaceae. The genus is pantropical, occurring in ...

'') exhibit similar reproductive strategies. Of course, guanacaste trees—like all

and semideciduous species in this part of the world—share in the water-conserving benefits of dry-season leaflessness. Guanacaste flowers are heavily visited by bees—insects that probably are responsible for pollination, as well. Guanacaste seed pods, however, are completely ignored by native fauna and they accumulate on the

forest floor The forest floor, also called detritus or wikt:duff#Noun 2, duff, is the part of a forest ecosystem that mediates between the living, aboveground portion of the forest and the mineral soil, principally composed of dead and decaying plant matter ...

underneath parent trees. The seeds are not eaten by any animals currently native where the tree occurs, rendering the plant an evolutionary anachronism: it has been suggested that guanacaste pods were among the foods exploited by certain species of

Pleistocene megafauna The Late Pleistocene to the beginning of the Holocene saw the extinction of the majority of the world's megafauna, typically defined as animal species having body masses over , which resulted in a collapse in faunal density and diversity acro ...

that became

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

some 10,000 years ago (e.g. giant ground sloths, giant bison). Within this scenario, the tree remains today without an effective seed-dispersing vector besides humans. As discussed above, the tough-coated guanacaste seeds do not begin to grow unless their protective covers are punctured in some way. This may be an adaptation designed to keep the seeds from germinating while still in the pods at the start of the

rainy season The rainy season is the time of year when most of a region's average annual rainfall occurs. Rainy Season may also refer to: * ''Rainy Season'' (short story), a 1989 short horror story by Stephen King * "Rainy Season", a 2018 song by Monni * '' ...

—and very likely still underneath the parent tree after having fallen from its crown. With more time to find them, foraging ground sloths (and other extinct mammals) could eat the pods and transport the seeds to a new site. The resulting mastication and digestion of the fruits would induce seed coat abrasion, which would help seed germination. Nowadays this role of mastication and dispersal has been taken up primarily by

horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 milli ...

and

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

. An insect pest, common to guanacaste trees of the Costa Rican Central Valley, produces spherical green

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 ...

s of diameter on new shoots in February and March. Similar parasitism seems to occur on guanacaste trees of the wet, southwestern lowlands (around Palmar Sur).

Cultivation and uses

The guanacaste is among the most majestic and aesthetically pleasing of tree species in its native range. Tolerant of a wide range of rainfall levels, temperatures, and soil conditions, they can thrive in most low-elevation, tropical habitats. Guanacaste trees are highly valued as ornamentals, and the shade they provide creates many an oasis on the searing and sun-baked plains in its Pacific slope habitat. It is widely grown as a shade tree to shelter

coffee Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially a ...

plantation Plantations are farms specializing in cash crops, usually mainly planting a single crop, with perhaps ancillary areas for vegetables for eating and so on. Plantations, centered on a plantation house, grow crops including cotton, cannabis, tob ...

s and for shade and

forage Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...

for cattle; it also improves soil fertility by

nitrogen fixation Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen ...

.Niembro Rocas (2002) The guanacaste is found in

USDA The United States Department of Agriculture (USDA) is an United States federal executive departments, executive department of the Federal government of the United States, United States federal government that aims to meet the needs of commerc ...

Growth Zones 10–12. The

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

is reddish-brown, lightweight (density ) and water-resistant; it is used to make items such as doors, windows, furniture, and cabinets, and for shipbuilding. It is considered a relatively sustainable resource for wooden furniture and design projects, largely due to the tree's ability to quickly reach large sizes, which also makes it easier to find large natural cuts up to several meters, which is rare for other slower-growing woods, such as oak or cedar. The town of La Cruz de Huanacaxtle in

Nayarit Nayarit, officially the Free and Sovereign State of Nayarit, is one of the 31 states that, along with Mexico City, comprise the Political divisions of Mexico, Federal Entities of Mexico. It is divided in Municipalities of Nayarit, 20 municipalit ...

(Mexico) derives its name from the fact that a cross used to stand there made of guanacaste wood. While the seed pods are still green, they are harvested and the seeds eaten boiled in Mexico. Healthy guanacaste trees generate massive, nearly annual crops of seeds. The attractive seeds are used in Costa Rica to make jewelry. In parts of Panama, the ripe seeds are heated in a fire until they pop like popcorn. These seeds demonstrate germination rates of nearly 100%. Guanacaste seedlings then grow rapidly, often reaching over in height in their first year. These aggressive reproductive characteristics might be beneficially exploited in

reforestation Reforestation is the practice of restoring previously existing forests and woodlands that have been destroyed or damaged. The prior forest destruction might have happened through deforestation, clearcutting or wildfires. Three important purpose ...

projects, though the plant is considered an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

in some places. Its roots are strong, and those of large trees may damage nearby structures. Guanacaste is commonly used to feed all kind of livestock; its foliage, fruits, and seeds are relished by cattle, pigs, goats, sheep, and horses. The parota tree is believed to provide medical benefits. In Mexican folk medicine, the sap is thought to aid illnesses such as influenza and bronchitis, while the astringent properties of its green fruit are used for diarrhea. The fruit and bark also contain tannins, which are useful for leather curing and soap manufacturing, while the sap can be used as a natural adhesive or substitute for glue, or chewed as a type of gum.

Synonyms

The guanacaste has in the past been referred to by these

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

s:ILDIS (2005) * ''

Albizia ''Albizia'' is a genus of more than 160 species of mostly fast-growing subtropical and tropical trees and shrubs in the subfamily Mimosoideae of the family Fabaceae. The genus is pantropical, occurring in Asia, Africa, Madagascar, America and A ...

longipes'' Britton & Killip * ''Enterolobium cyclocarpa'' (Jacq.) Griseb. (''

lapsus In philology, a lapsus (Latin for "lapse, slip, error") is an involuntary mistake made while writing or speaking. Investigations In 1895 an investigation into verbal slips was undertaken by a philologist and a psychologist, Rudolf Meringer and ...

'') * '' Feuilleea cyclocarpa'' (Jacq.) Kuntze * ''

Inga ''Inga'' is a genus of small tropical, tough-leaved, nitrogen-fixing treesElkan, Daniel. "Slash-and-burn farming has become a major threat to the world's rainforest" ''The Guardian'' 21 April 2004 and shrubs, subfamily Mimosoideae. ''Inga''s l ...

cyclocarpa'' (Jacq.) Willd. :Not to be confused with '' Inga cyclocarpa'' Ducke * ''

Mimosa ''Mimosa'' is a genus of about 600 species of herbs and shrubs, in the mimosoid clade of the legume family Fabaceae. Species are native to the Americas, from North Dakota to northern Argentina, and to eastern Africa (Tanzania, Mozambique, and ...

cyclocarpa'' Jacq. * ''Mimosa parota'' Sessé & Moc. * '' Pithecellobium cyclocarpum'' (Jacq.) Mart. * '' Prosopis dubia'' Kunth

Description

Ecology

Cultivation and uses

Synonyms

References

Further reading