A single tree can make 9 million seeds - and it's invading Queensland

EditionININUSGCCEnglishEnglishहिन्दीमराठीಕನ್ನಡதமிழ்বাংলাമലയാളംతెలుగుગુજરાતીWeatherSign InTOIToday's ePaperLive EditionININUSGCCEnglishEnglishहिन्दीमराठीಕನ್ನಡதமிழ்বাংলাമലയാളംతెలుగుગુજરાતીWeatherSign In TOIToday's ePaperLive NewsWorld NewsRest of World NewsIn 1937, a botanical garden in Tahiti planted an ornamental tree; today, a single tree can produce 8.9 million seeds and threaten Queensland’s World Heritage rainforestsTrendingRussia Missile AttackScotland Peatland RestorationChile WatershedNetanyahu US VisitIran Threatens USNewfoundland Moose PopulationDonald TrumpRussia Missile AttackScotland Peatland RestorationChile WatershedNetanyahu US VisitIran Threatens USNewfoundland Moose PopulationDonald TrumpRussia Missile AttackScotland Peatland RestorationChile WatershedNetanyahu US VisitIran Threatens USNewfoundland Moose PopulationDonald TrumpIn 1937, a botanical garden in Tahiti planted an ornamental tree; today, a single tree can produce 8.9 million seeds and threaten Queensland’s World Heritage rainforestsTOI World Desk / TIMESOFINDIA.

COM / Jul 25, 2026, 14:47 ISTCommentsShareAA+Text SizeSmallMediumLarge Photo: Steve Csurhes/ Department of Agriculture and Fisheries, Biosecurity Queensland. In 1937, a botanical garden in Tahiti planted an ornamental tree that would one day become a warning sign for some of the world’s most vulnerable rainforests. What began as a beautiful landscaping choice has grown into a serious biosecurity threat, with a single mature miconia tree capable of producing more than 8.

9 million seeds in one fruiting season and posing a major risk to Queensland’s World Heritage rainforests.A plant with a dangerous pastThe tree in question is miconia, a tropical plant native to the Americas that was once valued for its striking appearance. Its large leaves, purple undersides and lush growth made it attractive to gardeners, and that ornamental appeal helped it spread far beyond its original range.

Over time, however, miconia earned a far darker reputation in places such as Tahiti and Hawaii, where it became notorious for invading forests and smothering native vegetation, according to a report by the Department of Agriculture and Fisheries, Biosecurity Queensland.The Tahiti link goes back to 1937, when a botanical garden planted the species as an ornamental tree. From there, the plant escaped cultivation and spread aggressively across the island’s landscapes.

In places where it took hold, it formed dense stands that blocked sunlight from reaching the forest floor and pushed out native plants.Why Queensland is worriedQueensland treats miconia as a high-priority invasive weed for a reason. Biosecurity Queensland says the plant could cause irreversible ecological damage to the state’s subtropical and Wet Tropics rainforests, including World Heritage areas.

Those habitats are especially important because they support rare and endemic species found nowhere else on Earth.The concern is not just that miconia grows quickly. It is that one plant can multiply with extraordinary efficiency.

According to Queensland’s pest risk assessment, a mature miconia tree with around 200 fruiting panicles can produce over 8.9 million seeds in a single season. That scale of reproduction gives the plant a huge advantage, allowing one parent tree to seed entire invading populations.

How miconia takes overMiconia is especially dangerous in rainforest environments because of the way it changes the habitat around it. It invades the understorey, the layer beneath the tree canopy where many delicate plants grow. Rare orchids, ferns, shrubs and small native trees are particularly vulnerable because miconia reduces the amount of light they receive.

As the plant spreads, it can create barren understoreys and reduce ground cover. That not only harms biodiversity but can also lead to erosion. Queensland’s risk assessment notes that miconia’s shallow, spreading root system can destabilise hillsides, especially after heavy rain.

In tropical catchments, that instability can send sediment into streams and, eventually, damage reef ecosystems downstream.This is what makes the weed so much more than a garden escapee. It is a landscape changer.

Once established, it can alter the structure of a rainforest, affect water movement, reduce habitat quality for native animals and make the forest far less resilient.Where the plant can spreadIn Queensland, miconia is already treated as a restricted invasive plant under the Biosecurity Act 2014. Three species are currently of concern: Miconia calvescens, Miconia nervosa and Miconia racemosa.

Biosecurity Queensland says these species pose a significant threat to local rainforests, and all are targeted for eradication through the National Tropical Weeds Eradication Program.The species is suited to coastal northern Queensland’s climate, which is part of what makes it so worrying. Wet forests, rainforest gullies, forested creek lines and even domestic gardens are considered suitable habitat.

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