''Pentachaeta lyonii'', the Lyon's pentachaeta or Lyon's pygmydaisy, is an annual plant in the family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to southern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, where it is now known only from a few areas on the heavily developed coastline of

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world' ...

and Ventura Counties. It is a federally listed

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

Distribution

At one point in time there were 43 populations of ''P. lyonii'' distributed among the Santa Monica Mountains, Simi Valley, Palos Verdes Peninsula and Catalina Island. In a 2006 search only 21 ''Pentacheata'' populations could be located, with occurrences on the Palos Verdes Peninsula having long been deemed extirpated. Populations on Catalina Island were thought to be extirpated until 112 individuals were re-discovered in 2011 on a ridgeline near Two Harbors. The most recent area suspected of extirpation is Stunt Ranch where no flowering individuals have been seen since 1990, after an 8-year population decline.U.S. Fish and Wildlife Service. 1999. Recovery Plan for Six Plants from the Mountains Surrounding the Los Angeles Basin. In 2020 this elusive species was spotted once again by Catalina Island Conservancy botanists. Just 19 individuals were found in a location that roughly corresponds to a record from W.S. Lyon, who discovered the species in 1885. The plant received protected status in 1990.

Description

''Pentachaeta lyonii'' tends to grow in compact soil with little disturbance and few competitors. Plants have been grown in the greenhouse with light well aerated soil, but whether ''P. lyonii'' grows in compact soil due to a lack of competition or particular nutrient requirements has yet to be determined. The plant requires insect pollination to set seed.

References

External links

Calflora Database: ''Pentachaeta lyonii'' (Lyon's pentachaeta, Lyon's pygmydaisy)Jepson Manual eFlora treatment of ''Pentachaeta lyonii''USDA Plants Profile for ''Pentachaeta lyonii''UC CalPhotos gallery of ''Pentachaeta lyonii''
Astereae Endemic flora of California Natural history of the California chaparral and woodlands Natural history of the Santa Monica Mountains Natural history of Los Angeles County, California Natural history of Ventura County, California Taxa named by Asa Gray {{Astereae-stub