"Bush Currant" redirects here. Not to be confused with Currant Bush (Carissa spinarum).

The velvet tree, miconia, or bush currant (Miconia calvescens) is a species of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 in the family Melastomataceae

Melastomataceae

right|thumb|200px|Characteristic venation of many melastomesThe family Melastomataceae is a taxon of dicotyledonous flowering plants found mostly in the tropics comprising some 200 genera and 4500 species...

. It is native to 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...

 and Central

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 and South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 but is best known for being arguably the worst invasive plant

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 Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

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

Ecosystem

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

s. It is also similarly damaging in other tropical locales such as Tahiti

Tahiti

Tahiti is the largest island in the Windward group of French Polynesia, located in the archipelago of the Society Islands in the southern Pacific Ocean. It is the economic, cultural and political centre of French Polynesia. The island was formed from volcanic activity and is high and mountainous...

. The tree can grow to a height of 15 metres (49.2 ft) and has very large leaves, each up to 1 metres (3.3 ft) in length. Its purple and green leaves with flashy white veining made it attractive as an ornamental

Ornamental plant

Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...

, and it was imported to Hawaii and other new areas in the mid-twentieth century. Once it dispersed into the tropical moist forests

Tropical and subtropical moist broadleaf forests

Tropical and subtropical moist broadleaf forests , also known as tropical moist forests, are a tropical and subtropical forest biome....

 it took hold vigorously, invaded any spot in the understory

Understory

Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...

 that received patches of sunlight, and became a noxious weed

Weed

A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...

.

Miconia trees can flower several times a year and bear fruit simultaneously. The flowers are large 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 of light pink blossoms and the tiny purple fruits are half a centimeter in diameter and packed with minuscule seeds. The sweet fruits are attractive to birds and other animals which disperse the seeds. This heavy seed production and potential for long-distance dispersal help make miconia a threat. The seeds lie dormant in the soil of the forest, 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

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

.

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 there. Uprooting and herbicides are used to remove plants, but biological control has not yet met with great success. Teams of volunteers often lead expeditions into the forest to remove miconia plants by hand.

The plant has become an ecological disaster on Tahiti. One quarter of the rainforest there is now made up of miconia stands. For this reason, it is frequently called the "green cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

" on the island.

External links

• Miconia calvescens information and links from the Hawaiian Ecosystems at Risk project
  Hawaiian Ecosystems at Risk project
  The Hawaiian Ecosystems at Risk project 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 of harmful non-native species in Hawaii and the Pacific...
  
  
• Miconia calvescens detailed information and references from the Pacific Ecosystems at Risk project
• Miconia calvescens images: a gallery of copyright-free high-resolution photographs
• Miconia calvescens