The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.
Threatened species are any species which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of critical depensation, a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment.
The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status exist and are in use at international, multi-country, national and local levels as well as for consumer use.
The Hawaiian lobelioids are a group of flowering plants in the bellflower family, Campanulaceae, all of which are endemic to the Hawaiian Islands. This is the largest plant radiation in the Hawaiian Islands, and indeed the largest on any island archipelago, with over 125 species. The six genera can be broadly separated based on growth habit: Clermontia are typically branched shrubs or small trees, up to 7 metres (23 ft) tall, with fleshy fruits; Cyanea and Delissea are typically unbranched or branching only at the base, with a cluster of relatively broad leaves at the apex and fleshy fruits; Lobelia and Trematolobelia have long thin leaves down a single, non-woody stem and capsular fruits with wind-dispersed seeds; and the peculiar Brighamia have a short, thick stem with a dense cluster of broad leaves, elongate white flowers, and capsular fruits.
A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as known only by living members kept in captivity or as a naturalized population outside its historic range due to massive habitat loss.
Encephalartos horridus, the Eastern Cape blue cycad, is a small, low-growing cycad up to 0.9 m (3.0 ft) high and 0.9 m (3.0 ft) wide. It is a native of Eastern Cape Province, South Africa, and found in arid shrublands, most commonly on ridges and slopes with shallow soils. The species is particularly known for its distinctly blue-gray leaves, although the degree of coloration can vary significantly. The species name horridus is Latin for 'bristly', after the plant's stiff, spiny leaflets.
Clermontia peleana is a rare species of flowering plant in the bellflower family known by the common name Pele clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as `oha wai. This plant is endemic to the island of Hawaii, where it is known from a few individuals. It is a federally listed endangered species of the United States.
Cyanea copelandii is a rare species of flowering plant in the bellflower family known by the common name treetrunk cyanea. It is endemic to Maui, where there are no more than 250 individuals remaining in the wild. It is a federally listed endangered species of the United States. Like other Cyanea it is known as hāhā in Hawaiian.
Cyanea glabra is a rare species of flowering plant in the bellflower family known by the common name smooth cyanea. It is endemic to Maui, where there are twelve plants remaining in the wild. It was federally listed as an endangered species of the United States with nine other Maui Nui endemics in 1999. Like other Cyanea it is known as haha in Hawaiian.
Cyanea procera is a rare species of flowering plant in the bellflower family known by the common name Molokai cyanea. It is endemic to Hawaii, where it is known only from the island of Molokaʻi. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
Cyanea superba is a rare species of flowering plant in the bellflower family known by the common names Mt. Kaala cyanea and superb cyanea. It is endemic to the island of Oahu, but it is now extinct in the wild. It exists in cultivation and some individuals have been planted in appropriate habitat. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
Encephalartos tegulaneus, the Kenyan giant cycad, is a species of cycad endemic to Kenya. It occurs in Eastern Province near Embu, Kenya, and on the Matthews Range in Rift Valley Province.
