Pentachaeta bellidiflora
White-rayed pentachaeta is making a comeback at Edgewood! This federally endangered plant is believed now to survive in just a few locations, one of which happens to be in our own backyard. The largest known patch is found west of I280 in the area called “The Triangle,” adjacent to Edgewood Natural Preserve. This pretty wildflower is a small annual, grown from a slender tap-root, with white, daisy-like flowers that typically bloom from March to June.
The white-rayed pentachaeta is one of two endangered plant species, along with the San Mateo thornmint, targeted for restoration as part of Project 467, the Friends of Edgewood’s comprehensive habitat management program initiated in 2018.
Species Description
White-rayed pentachaeta’s green leaves measure less than 4.5 cm (1.8 inches) long and one millimeter wide, are narrowly linear and fringed with tiny hairs (ciliate). The sparsely hairy stems are 6-17 cm (2-7 inches) in length and green to reddish in color. The yellow and white corollas have five lobes and each of the 16 to 38 round florets has linear, acute styletips.
Restoration Efforts
Urbanization and development have caused the loss of most white-rayed pentachaeta habitat, which once was found from Marin to Santa Cruz counties. The serpentine grasslands at Edgewood Natural Preserve offer an ideal location to promote restoration of the species, but threats from climate change, nitrogen pollution from the nearby highway, and invasive, non-native grasses and weeds mean that we do not have time to waste in protecting the few remaining stands of one of California’s most charming wildflowers.
The Friends of Edgewood is collaborating with San Mateo County Parks, Creekside Science, U.S. Fish and Wildlife Service, and California Fish and Wildlife Service to help the white-rayed pentachaeta regain its foothold at Edgewood. Creekside Science conducted a seed increase at their conservation nursery using seeds donated from San Francisco Water Power Sewer, who own the Triangle, the location of the largest source colony. More than 82,000 seeds were first planted at four restored locations at Edgewood in November 2023. In March 2024, Creekside Science documented 18,503 plants total at Edgewood, a rousing success! More seeds were planted in November 2024, so stay tuned for more results.
If you would like to contribute to saving the white-rayed pentachaeta at Edgewood Natural Preserve, please make a donation to Project 467 and help us protect and restore this fragile endangered species.