Liliwai (Acaena exiga)
Hawaiian Endemic Species
Acaena exigua is a very rare species of flowering plant in the rose family known by the common name liliwai. It is endemic to Hawaii, where it is known from Kauai and west Maui. It had not been seen or collected since 1957 and was feared extinct until 1997, when one plant was discovered in a remote montane bog on Maui. The plant died in 2000. Liliwai is a small sized perennial plant and is very difficult to survey because of its small stature and the large area of intact habitat with dense growth.
Threats or Causes of Endangerment
Liliwai is currently endangered by feral pigs and goats. They eat and degrade the habitat, allowing invasive species such as rush, Japanese mat rush, glorybush, hair cat's-ear, Maui mapakani, Hamakua pamaki, and narrow leaved carpetgrass to grow in the bare ground dug up by the animals. Slugs and rats also feed on the Lilwai seedlings, making it hard for them to grow. Other causes of endangerment could be loss of pollinators, dispersal agents, disease, inbreeding depression, droughts, and rare frost episodes.
Some possible solutions that scientist are trying to make are keeping a conserved amount of Liliwai protected, giving it the opportunity to grow and disperse without the outside interference of invasive species. There has not been any great successes in these projects, possibly because of the difficulty of locating the plant species.