''Psidium oligospermum'', the Galápagos guava or guayabillo, is a small

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, including only woody plants with secondary growth, plants that are ...

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

native to the tropical Americas, ranging from Mexico through the Revillagigedo Islands, Central America,

Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

, the

Windward Islands french: Îles du Vent , image_name = , image_caption = ''Political'' Windward Islands. Clockwise: Dominica, Martinique, Saint Lucia, Saint Vincent and the Grenadines, and Grenada. , image_alt = , locator_map = , location = Caribbean SeaNorth ...

, the

Galápagos Islands The Galápagos Islands (Spanish: , , ) are an archipelago of volcanic islands. They are distributed on each side of the equator in the Pacific Ocean, surrounding the centre of the Western Hemisphere, and are part of the Republic of Ecuador ...

, and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

to central Brazil and northwestern Argentina.

Description

''Psidium oligospermum'' is either a small tree or shrub that ranges up to in height and up to in diameter, with smooth, pinkish-grey

bark Bark may refer to: * 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) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, ...

. It has wide-spreading branches with dotted grey branchlets with reddish to white or yellowish "

trichome Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a pla ...

s" or hairs. The branchlets tend to become more smooth at the edges and the bark more stringy, and the

terminal Terminal may refer to: Computing Hardware * Terminal (electronics), a device for joining electrical circuits together * Terminal (telecommunication), a device communicating over a line * Computer terminal, a set of primary input and output devic ...

branchlets and

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are sometimes covered with a scurfy reddish bloom.Duncan M. Porter (1968) ''Annals of the Missouri Botanical Garden: Psidium (Myrtaceae) in the Galapagos Islands'' Vol. 55, No. 3, p. 368-371 Its leaves are opposite and elliptic to

ovate Ovate may refer to: *Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe *Ovates, one of three ranks of membership in the Welsh Gorsedd *Vates In modern English, the nouns vates () and ovat ...

, with the tips of the leaves being

acute Acute may refer to: Science and technology * Acute angle ** Acute triangle ** Acute, a leaf shape in the glossary of leaf morphology * Acute (medicine), a disease that it is of short duration and of recent onset. ** Acute toxicity, the adverse eff ...

to acuminate. The base of the leaf is narrowly cuneate and is decurrent on the stalk of the leaf. The entire leaf is glabrous and is generally darker on the upper face and paler on the other side. The leaves are generally long and wide, and the petioles, or leaf stalks, are generally long. The buds of ''Psidium oligospermum'' are pear-shaped or "

pyriform Piriform, sometimes ''pyriform'', means pear-shaped (from Latin ''pirum'' "pear" and ''forma'' "shape"). It may also refer to: Going pear-shaped * Going wrong or going pear-shaped Anatomy * Piriform aperture, more commonly known as anterior n ...

" and connected to the base of the branchlet, extending about out. The bud is glabrous except for a minute hole at the apex with a few trichomes protruding outward.

Flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s are white, occur on branches of recent growth, and are relatively small, being in diameter. Its

berries A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...

are spherical in shape and are glabrous except for ripples created from

glands In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

in the berries. The berries are yellow when mature and turn black or a reddish-brown when dried. They are in diameter and the " pericarp", or wall of the berry is about thick. The

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s are angular, dark, and long, and each

locule A locule (plural locules) or loculus (plural loculi) (meaning "little place" in Latin) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus). In angiosperms (flowering plants), the term ''locule'' usu ...

contains several.

Habitat and ecology

In the

''Psidium oligspermum'' is found on the islands Fernandina,

Isabella Isabella may refer to: People and fictional characters * Isabella (given name), including a list of people and fictional characters * Isabella (surname), including a list of people Places United States * Isabella, Alabama, an unincorpora ...

, Pinta, Santa Cruz, and

Santiago Santiago (, ; ), also known as Santiago de Chile, is the capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated region, the Santiago Metropolitan Region, whose ...

. It typically grows in

arid A region is arid when it severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic. Most ar ...

lowlands and moist

uplands Upland or Uplands may refer to: Geography *Hill, an area of higher land, generally *Highland, an area of higher land divided into low and high points *Upland and lowland, conditional descriptions of a plain based on elevation above sea level *I ...

. On Socorro Island in the Revillagigedo Islands, it is a canopy tree in upper-elevation ''Ilex socorroensis'' forest, with ''

Ilex socorroensis ''Ilex socorroensis'' is a species of flowering plant in the holly genus (''Ilex''). It is a tree native to Socorro Island in the Revillagigedo Islands The Revillagigedo Islands ( es, Islas Revillagigedo, ) or Revillagigedo Archipelago are a ...

Guettarda insularis ''Guettarda'' is a plant genus in the family Rubiaceae. Most of these plants are known by the common name velvetseed. Estimates of the number of species range from about 50 Anthony J. Huxley, Mark Griffiths, and Margot Levy (editors). 1992. ''Th ...

'', and ''

Sideroxylon socorrense ''Sideroxylon socorrense'' is a plant species in the family Sapotaceae. It is endemic to Mexico, occurring only on Socorro in the Revillagigedo Islands. On its island home, this small tree grows in habitat that is at least seasonally humid. Thi ...

''.Ricardo Rodriguez-Estrella, Eustolia Mata, Laura Rivera, Ecological Notes on the Green Parakeet of Isla Socorro, Mexico, The Condor, Volume 94, Issue 2, 1 May 1992, Pages 523–525, https://doi.org/10.2307/1369224

Uses

The berries of ''Psidium oligospermum'' are edible, reportedly with a slight taste of

turpentine Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthene, terebinthine and (colloquially) turps) is a fluid obtained by the distillation of resin harvested from living trees, mainly pines. Mainly used as a special ...

, and geese are reported to frequently consume the berries. The

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...

of the tree is used locally in the Galápagos Islands as fencing or a

building material Building material is material used for construction. Many naturally occurring substances, such as clay, rock (geology), rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materia ...

, but is not very hardy nor enduring.Julian Fitter, Daniel Fitter, David Hosking (2002) ''Wildlife of the Galápagos: Second Edition''

References

{{Taxonbar, from=Q15380016, from2=Q25698326 oligospermum Flora of Mexico Flora of the Revillagigedo Islands Flora of Cuba Flora of Central America Flora of Puerto Rico Flora of the Windward Islands Flora of the Galápagos Islands Flora of northern South America Flora of western South America Flora of Brazil Flora of Northwest Argentina Plants described in 1828