Lysimachia maxima is a rare species of flowering plant in the family Myrsinaceae

Myrsinaceae

Myrsinaceae, or the Myrsine family, is a rather large family from the order Ericales. It consists of 35 genera and about 1000 species....

 known by the common name Pelekunu Trail yellow loosestrife. It is endemic to 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 there are only two small populations remaining on the island of Molokai

Molokai

Molokai or Molokai is an island in the Hawaiian archipelago. It is 38 by 10 miles in size with a land area of , making it the fifth largest of the main Hawaiian Islands and the 27th largest island in the United States. It lies east of Oahu across the 25-mile wide Kaiwi Channel and north of...

. It is federally listed as an endangered species

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

 of the United States.

This is a shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

 with sprawling branches lined with leaves growing in clusters of three. The solitary flowers are purple in color. The plant grows only in the wet forests of the Pelekunu Mountains of Molokai. The most recent surveys revealed a total of twenty individuals, ten in each of the two populations.

The plant is threatened by the invasion

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....

 of introduced species

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 of animals such as feral pigs and feral goat

Feral goat

The feral goat is the domestic goat when it has become established in the wild. Feral goats occur in Australia, New Zealand, Ireland, Great Britain, Hawaii, the Galapagos and in many other parts of the world...

s, and plants such as Koster's curse

Clidemia hirta

Clidemia hirta, commonly called soapbush or Koster's Curse, is a perennial shrub.It is an invasive plant species in many tropical regions of the world, creating serious damage.-Distribution:...

 (Clidemia hirta) in its habitat. The plant is vulnerable because of its small numbers; a single event could conceivably cause its extinction.

Officials have released the leaf-eating insect Lius poseidon into the habitat as an agent of biological pest control

Biological pest control

Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...

against Koster's curse. It is too early to determine how successful this effort has been.