Higher classification Daisy family | Scientific name Pentachaeta lyonii Rank Species | |
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Similar Daisy family, Astragalus brauntonii, Perityle emoryi, Acourtia microcephala, Malacothrix saxatilis | ||
Pentachaeta lyonii, the Lyon's pentachaeta or Lyon's pygmydaisy, is an annual plant in the aster family. It is endemic to southern California, where it is now known only from a few areas on the heavily developed coastline of Los Angeles and Ventura Counties. This is a federally listed endangered species.
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 and Santa Catalina Island having long been deemed extirpated. 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.
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.