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About Parrot's Feather

Myriophyllum aquaticum, commonly known as parrot feather or parrot feather watermilfoil, is a submerged to emergent aquatic perennial native to South America's Amazon River basin. Its feathery, bright green whorled leaves rise above the water surface in attractive plume-like formations, giving it a distinctive parrot-feather appearance. Each whorl contains four to six finely divided leaves arranged around the stem. While visually appealing in water features, this plant is classified as a highly invasive species across much of North America, Europe, and Australasia. It reproduces almost entirely vegetatively — even tiny stem fragments can regenerate into new plants, clogging waterways and outcompeting native aquatic vegetation. Dense mats reduce dissolved oxygen, harming fish and invertebrates. It was originally introduced through the aquarium trade in the early 1900s. Many jurisdictions now ban its sale and transport.

• Fast-growing

How to care for Parrot's Feather

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At a Glance

Bloom time

Fragrance

Toxicity

History

Myriophyllum aquaticum is native to South America, most extensively in the Amazon basin but also in southern South America (Paraguay, southern Brazil, northern Argentina). It grows as a partially-submerged aquatic plant, with fine-textured whorled feathery submerged foliage (often blue-green) and emergent portions of stem rising 10-30 cm above the water surface bearing similar blue-green whorled feathery leaves. Its attractive ornamental appearance led to worldwide distribution in the 19th and 20th centuries as an aquarium plant, ornamental pond plant, and water-garden ornamental. However, the species has become one of the most serious invasive aquatic plants in temperate and subtropical waterways of the United States, Europe, the UK, Australia, New Zealand, South Africa, and Japan.

In warm water bodies without winter freezing, it forms dense intergrown mats that block navigation, impede water flow, shade out native submerged plants, reduce dissolved oxygen, and support mosquito-vector breeding. Importantly, only male plants are known outside of South America; the species has reproduced globally only by vegetative stem fragments, which has done nothing to slow its spread. Sale and transport is banned or restricted in the United Kingdom (banned 2014 under the Wildlife and Countryside Act), European Union (listed on the EU List of Invasive Alien Species of Union Concern 2016), Australia, New Zealand, and at least 15 US states.

Correct aquarium and pond stewardship is especially important because fragments hitching a ride on boats or released aquarium material have been the primary vector. Myriophyllum aquaticum was introduced to North America in the 1890s as an ornamental aquarium plant and quickly escaped into waterways. By the 1940s it was established across the southern United States. Its ability to survive in both aquatic and semi-terrestrial conditions made containment nearly impossible. It is now listed as a noxious weed in many countries. Ironically, researchers have studied its exceptional nutrient uptake for phytoremediation — using it to clean wastewater in controlled environments where escape is prevented.

Symbolism & meaning

Related plants

Plants with similar care

• Chinese AbeliaAbelia chinensis
• Fragrant AbeliaAbelia mosanensis
• Large-Flowered AbeliaAbelia uniflora
• Glossy AbeliaAbelia x grandiflora

Frequently asked questions