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Guanacaste (tree)
Encyclopedia
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of flowering tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
in the pea
Pea
A pea is most commonly the small spherical seed or the seed-pod of the pod fruit Pisum sativum. Each pod contains several peas. Peapods are botanically a fruit, since they contain seeds developed from the ovary of a flower. However, peas are considered to be a vegetable in cooking...
family, Fabaceae
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
, that is native to tropical
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
regions of the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
, from central 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...
south to northern Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
(Roraima
Roraima
Roraima is the northernmost and least populated state of Brazil, located in the Amazon region. It borders the states of Amazonas and Pará, as well as the nations of Venezuela and Guyana. The population is 400,000 and the capital is Boa Vista...
) and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
. It is known for its large proportions, its expansive, often spherical crown, and its curiously shaped seedpods. The abundance of this tree, especially in Guanacaste Province
Guanacaste Province
Guanacaste is a province of Costa Rica located in the northwestern part of the country, along the coast of the Pacific Ocean. To the north it borders Nicaragua. To the east is the Alajuela Province, and to the southeast is the Puntarenas Province. It is the most sparsely populated of all the...
, Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
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 of Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
.
In North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
it is often called (somewhat ambiguously) "Elephant Ear Tree
Elephant Ear Tree
The common name elephant ear tree typically refers to Enterolobium cyclocarpum The name may also refer to Macaranga gigantea....
", due to the shape of the seed pods. Other common names include Devil's Ear and Earpod Tree, parota and orejón (Spanish
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...
) or huanacaxtle (Nahuatl). In El Salvador
El Salvador
El Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...
, it is known as conacaste.
Description
Guanacaste is a medium-sized to large treeTree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
growing to 25–35 m tall, with a trunk up to 3.5 m diameter. Unusual in a tree of these proportions, buttresses are completely lacking. The bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
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 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
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are bipinnate compound, 15–40 cm long and 17 cm broad with a 2–6 cm petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
bearing 4–15 pairs of pinnae, each pinna with 40–70 leaflets; the leaflets are slender oblong, 8–15 mm long by 2–4 mm wide. Near its base, the twiggy petiole bares 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. Guanacaste is evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
, or briefly deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
for 1–2 months during the dry season
Dry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
. 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 leaves' renewal is the appearance of globular inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s (3 cm) in the axils of the new leaves. Supported by a long pedestal (4 cm), each spherical white head - composed of about fifty individual flowers - sports thousands of thin, filamentous stamens as its major feature. The blossoms themselves each consist of about twenty stamens and a single pistil, bound together at the base by a short, green, tubular corolla and an even shorter calyx, just 5 mm 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, nine or ten 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 ceased.
Guanacaste fruits are large (7–12 cm diameter) glossy dark brown indehiscent and spirally organized pods, shaped like orbicular disks. Their shape suggests the usual Mimosoideae
Mimosoideae
Mimosoideae is a subfamily of the flowering plant family Fabaceae characterized by flowers with small petals and numerous prominent stamens...
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 8-20 radially arranged seeds, 14.5–17.5 mm long, 7.8–11.2 mm wide, and 6.2–7.2 mm thick and weighing about 1 g. Guanacaste seeds are brown and marked with a conspicuous light brown or orange ring. They are also very hard - resembling small stones rather than tree seeds in their strength and durability. In order for germination to occur, the hard seed coat must be broken to enable water to reach the embryo. Otherwise, they will lie dormant indefinitely. Fruit ripening last from March to April, as the green pods turn brown in the Guanacaste crown and are slowly shed. Vigorous trees will 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.
Ardillo (Cojoba arborea
Cojoba arborea
Cojoba arborea is a leguminous tree of the family Fabaceae found in the Caribbean, Mexico, and Central America, southward to Ecuador in South America at elevations of...
) and Iguano (Dilodendron costaricense) possess similar bipinnate leaves with extra-fine leaflets. Though of equally impressive stature, these two trees can be distinguished readily from Guanacaste: Ardillo has tan-colored, heavily wrinkled and rough bark - nothing like Guanacaste's unmistakably gray, and vertically cracked cortex. Iguano's leaflets are serrate (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 nine months - so that seed maturation will coincide with the start of the rainy season. This adaptive behavior presumably is designed to give germinating seedlings as much time as possible to establish root systems before the start of the next dry season. Both JatobáJatobá
Hymenaea courbaril is a tree common to the Caribbean, Central, and South America. It is a hardwood that is used for furniture, flooring and decorative purposes....
(Hymenaea courbaril) and Cenizaro (Albizia saman) exhibit similar reproductive strategies. Of course, Guanacaste trees - like all deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
and semi-deciduous
Semi-deciduous
Semi-deciduous is a botanical term which refers to plants that lose part of their foliage, also Semi-deciduous plants can mean, that plants can lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and...
species in this part of the world - share in the water conserving benefits of dry season
Dry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
leaflessness.
Guanacaste flowers are heavily visited by bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s - 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 underneath parent trees. The seeds are not eaten by any animals currently native where the tree occurs. Perhaps Guanacaste pods were among the foods exploited by certain species of Pleistocene megafauna
Pleistocene megafauna
Pleistocene megafauna is the set of species of large animals — mammals, birds and reptiles — that lived on Earth during the Pleistocene epoch and became extinct in a Quaternary extinction event. These species appear to have died off as humans expanded out of Africa and southern Asia,...
that became extinct
Quaternary extinction event
The Quaternary period saw the extinctions of numerous predominantly larger, especially megafaunal, species, many of which occurred during the transition from the Pleistocene to the Holocene epoch. However, the extinction wave did not stop at the end of the Pleistocene, but continued especially on...
some 10,000 years ago (e.g. giant ground sloths, giant bison
Bison latifrons
Bison latifrons is an extinct species of bison that lived in North America during the Pleistocene. Also known as the giant bison, it reached a shoulder height of 2.5 metres , and had horns that spanned over 2 metres...
). Under this scenario, the tree remains today without an effective seed-dispersing vector - except humans, that is.
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 - 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.
An insect pest, common to Guanacaste trees of the Costa Rican Central Valley
Costa Rican Central Valley
The Central Valley is a plateau and a geographic region of central Costa Rica. The land in the valley is a relative plain, despite being surrounded by several mountains and volcanos, the latter part of the Central Range. The region houses almost three quarters of Costa Ricans, and includes the...
, produces spherical green gall
Gall
Galls or cecidia are outgrowths on the surface of lifeforms caused by invasion by other lifeforms, such as parasites or bacterial infection. Plant galls are abnormal outgrowths of plant tissues and can be caused by various parasites, from fungi and bacteria, to insects and mites...
s of 1.5 cm diameter on new shoots in February and March. Similar parasitism seems to occur on Guanacaste trees of the wet, southwestern lowlands (around Palmar Sur
Palmar Sur
Palmar Sur is a town in Costa Rica, located next to Palmar Norte in the Osa region of Puntarenas Province. Palmar Norte and Palmar Sur are separated by the Rio Terraba. Palmar Sur has a regional airport that has daily flights arriving from San Jose on two regional airlines...
).
Cultivation and uses
It is widely grown as a shade tree to shelter coffee plantation
Plantation
A plantation is a long artificially established forest, farm or estate, where crops are grown for sale, often in distant markets rather than for local on-site consumption...
s and for shade and forage
Forage
Forage is plant material 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 more loosely to include similar plants cut for fodder and carried to the animals, especially...
for cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
; it also improves soil fertility by nitrogen fixation
Nitrogen fixation
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...
. Guanacaste is in USDA
United States Department of Agriculture
The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...
Growth Zones 10-12.
The wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
is reddish-brown, lightweight (density 0.34–0.6 g/cm³) and water-resistant; it is used to make items such as doors, windows, furniture, cabinets, and for shipbuilding. The town of La Cruz de Huanacaxtle
La Cruz de Huanacaxtle
La Cruz de Huanacaxtle is a Mexican fishing village situated on the Pacific Ocean's Bahía de Banderas in the state of Nayarit. It is situated approximately 25 km from Puerto Vallarta, Jalisco...
in Nayarit
Nayarit
Nayarit officially Estado Libre y Soberano de Nayarit is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 20 municipalities and its capital city is Tepic.It is located in Western Mexico...
(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...
) 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
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...
. Healthy Guanacaste trees generate massive, nearly annual crops of seeds. The attractive seeds are used in Costa Rica to make jewelry. These seeds demonstrate germination rates of nearly 100%. Guanacaste seedlings then grow rapidly, often reaching over one meter in height in their first year of life. These aggressive reproductive characteristics might be beneficially exploited in reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
projects; on the other hand, the plant is considered an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in some places. Its roots are strong and those of large trees may damage nearby structures.
Synonyms
Guanacaste has in the past been referred to by the following junior synonyms:- AlbiziaAlbiziaAlbizia is a genus of about 150 species of mostly fast-growing subtropical and tropical trees and shrubs in the subfamily Mimosoideae of the legume family, Fabaceae. The genus is pantropical, occurring in Asia, Africa, Madagascar, Central, South, and southern North America and Australia, but mostly...
longipes Britton & Killip - Enterolobium cyclocarpa (Jacq.) Griseb. (lapsusLapsusA lapsus is an involuntary mistake made while writing or speaking. According to Freud's early psychoanalytic theory, a lapsus represents a missed deed that hides an unconscious desire....
) - Feuilleea cyclocarpa (Jacq.) Kuntze
- IngaIngaInga is a genus of small tropical, tough-leaved, nitrogen-fixing trees and shrubs, subfamily Mimosoideae. Ingas leaves are pinnate, and flowers are generally white...
cyclocarpa (Jacq.) Willd.
- Not to be confused with Inga cyclocarpa Ducke
- MimosaMimosaMimosa is a genus of about 400 species of herbs and shrubs, in the subfamily Mimosoideae of the legume family Fabaceae. The generic name is derived from the Greek word μιμος , meaning "mimic."...
cyclocarpa Jacq. - Mimosa parota Sessé & Moc.
- PithecellobiumPithecellobiumPithecellobium is a genus of flowering plants in the pea family, Fabaceae. The generic name is derived from the Greek words πιθηκος , meaning "ape" or "monkey," and ελλοβιον , meaning "earring," which refers to the coiled shape of the seedpods.Delimitation to the closely related Albizia is a matter...
cyclocarpum (Jacq.) Mart. - ProsopisProsopisProsopis is a genus of flowering plants in the pea family, Fabaceae. It contains around 45 species of spiny trees and shrubs found in subtropical and tropical regions of the Americas, Africa, Western Asia, and South Asia. They often thrive in arid soil and are resistant to drought, on occasion...
dubia Kunth
- Mimosa