Nonnative Species

Lopa trees.

NPS photo.

What are Invasive Species?

An invasive species can be an animal, a plant, an insect, or any other living thing that is:

• not native to an area
• able to pervade a region because of insufficient checks (such as natural predators or diseases).

Invasive species can be found in all kinds of areas, including forests, waterways, and urban environments.

Why Are Invasive Species Bad?

They can take over a habitat, crowding out important local species that other plants and animals depend upon.Invasives change what can grow and thrive in an area, which affects the whole food chain.

How are Invasive Species Introduced?

Most invasive species are introduced to a new region through human activity. Some are intentional actions, such as:

• agricultural crops,
• landscaping and ornamental plants,
• released or abandoned pets, and
• bait fish.

Others arrive through unsuspecting human carriers.

• They hitchhike on visitors’ clothes, shoes, gear, or transport.
• Boaters move invasive species that have attached to their equipment or clothing to new bodies of water.
• Hikers and hunters move invasive species around through mud on boots and other equipment.
• Drivers move invasive species that catch in their wheel wells, tires, or grills.

 

Although a vibrant beauty the Fa'apasi is not a native plant to American Samoa.

NPS Photo/T. Sagapolutele

Fa’apasī / African Tulip Tree

Scientific Name: Spathodea Campanulata
Habitat: Roadsides, open woods, and disturbed hillsides.
Leaves: Evergreen tree with large, opposite, pinnate leaves. Leaflets are oval, smooth-edged, and glossy green, with a slightly pointed tip. Young leaves may appear lighter and softer, while mature leaves become thicker and darker.
Flowers: Bright orange-red, trumpet-shaped clusters appear throughout the year, often most visible after heavy rains.
Fruit: Long, narrow, woody capsules that turn brown when mature. Each capsule splits open to release numerous flat, winged seeds dispersed by wind.

Effects: Seeds and sap are mildly toxic if ingested; can cause stomach upset. The tree is mainly invasive, outcompeting native plants and altering habitats.

 

While common to see around Tutuila the Fuapepe is nonnative to the island.

NPS Photo/T. Sagapolutele

Fuapepe / Ipil Ipil

Scientific Name: Leucaena leucocephala
Habitat: Roadsides, open fields, and disturbed areas; thrives in tropical and subtropical regions.
Leaves: Evergreen, bipinnate (twice divided), feathery, bright green, with many small leaflets.
Flowers: Small, creamy-white, round, fluffy clusters appearing along the branches.
Fruit: Long, flat, brown pods containing several seeds; pods mature and dry on the tree.

Effects: Fast-growing, nitrogen-fixing tree used for fodder and soil improvement; can become invasive, outcompeting native plants.

 

If you look closely you may notice this nonnative plant climbing almost anything around it.

NPS Photo/T. Sagapolutele

Fue Lautele

Scientific Name: Merremia Peltata
Habitat: Disturbed forests, roadsides, and open areas; climbs over trees and shrubs.
Leaves: Large, heart-shaped, glossy green, with long petioles.
Flowers: Funnel-shaped, white to pale pink, usually solitary or in small clusters.
Fruit: Small capsule containing several seeds; dispersal by wind or animals.

Effects: Fast-growing vine; smothers native vegetation, can dominate forest edges, considered invasive in many areas.

 

A close up view of the seeds in the seed pods of a Lopa Tree.

NPS Photo

Lōpā/ Red Bean Tree

Scientific name: Adenanthera Pavonina
Habitat: Roadsides, open fields, and village yards; thrives in tropical lowlands.
Leaves: Evergreen, bipinnate (feathery), with many small, oval leaflets.
Flowers: Small, fragrant, yellowish white, in elongated clusters.
Fruit: Long, flat pods containing bright red seeds; seeds are hard and shiny.
Effects: Ornamental and shade tree; seeds are toxic if ingested in large quantities.