''Miconia calvescens'', the velvet tree, miconia, or bush currant, is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

in the family

Melastomataceae Melastomataceae is a family of dicotyledonous flowering plants found mostly in the tropics (two-thirds of the genera are from the New World tropics) comprising c. 175 genera and c. 5115 known species. Melastomes are annual or perennial herbs, s ...

. It is native to

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

and

Central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known a ...

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 sou ...

and it has become one of the world's most

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...

. Miconia trees can flower several times a year and bear fruit simultaneously. The

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are forme ...

s are large

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

s of white to light pink blossoms. The tiny purple fruits are about half a centimeter in diameter and packed with about 120–230 minuscule seeds. The sweet fruits are attractive to birds and other animals which disperse the seeds. A young tree with only two flower panicles can produce seeds in its first fruiting season. This heavy seed production and potential for long-distance dispersal help make miconia an invasive threat. The seeds can lie dormant in the soil of the forest for more than 12 years, and whenever a break in the canopy allows sun to shine through to a patch of soil the seeds there undergo germination. Once the plants grow to full height, their enormous leaves shade out all the space below them, preventing any other plant from growing nearby. It also has a shallow root system that facilitates

soil erosion Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, a ...

. The tree can grow to a height of and has very large leaves, each up to in length. Its purple and green leaves with flashy white veining made it attractive as an ornamental, and it was imported to Hawaii and other new areas in the mid-twentieth century.

Invasive species

The

Invasive Species Specialist Group Invasive may refer to: * Invasive (medical) procedure * Invasive species * Invasive observation, especially in reference to surveillance Surveillance is the monitoring of behavior, many activities, or information for the purpose of informati ...

list the tree as one of the world's 100 most invasive species in the Global Invasive Species Database. The seeds are dispersed from gardens into natural forest habitats by fruit-eating birds. Once dispersed into

tropical moist forests Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature. Description TSMF is generally found in large, discont ...

it takes hold vigorously, invading any spot in the

understory In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abo ...

that receives patches of sunlight, and becomes a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is injurious to agricultural or horticultural crops, natural habitats or ecosystems, or humans or li ...

. It is known for being the worst invasive plant in

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

, where it is commonly referred to as the "purple plague", and threatens to destroy entire

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

s. The velvet tree has been known to replace the native understory of Hawaiian mountainous forests. The plant itself has a shallow root system as compared to the native species. This shallower root systems are unable to bind the soil together which has led to landslides in certain regions of Hawaii. Hawaiian populations of miconia were first discovered in the 1990s, and since the plant's invasive potential was already well-known, control and eradication efforts began immediately. Uprooting and herbicides are used to remove plants, but

biological control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also i ...

has not yet met with great success. Teams of volunteers often lead expeditions into the forest to remove miconia plants by hand. The tree has become an invasive species in Tahiti and a quarter of the rainforest on the island is now made up of miconia stands. For this reason, it is frequently called the "green

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

" on the island. In Sri Lanka it invades upcountry mountain forest areas. It forms monospecific stands that shade out native vegetation.Lalith Gunasekera, ''Invasive Plants: A guide to the identification of the most invasive plants of Sri Lanka'', Colombo 2009, p. 103–104.

References

External links

''Miconia calvescens'' information and links
from the

Hawaiian Ecosystems at Risk project The Hawaiian Ecosystems at Risk project (HEAR) is a government-funded project created to provide technology, methods, and information to decision-makers, resource managers, and the general public to help support effective science-based management ...

''Miconia calvescens'' detailed information and references
from th
Pacific Ecosystems at Risk project
a gallery of copyright-free high-resolution photographs

{{Taxonbar, from=Q140905 calvescens Flora of Central America Flora of South America Trees of Bolivia Trees of Brazil Trees of Colombia Trees of Ecuador Trees of Guatemala Trees of Chiapas Trees of Guerrero Trees of Oaxaca Trees of Tabasco Trees of Veracruz Trees of Panama Trees of Paraguay Trees of Peru Invasive plant species in Sri Lanka