Tiburon Paintbrush

Castilleja affinis ssp. neglecta (Flowering Plants)

Species Description

Tiburon Paintbrush is a short, shrubby perennial plant in the snapdragon family. As its name suggests, it is found on the Tiburon peninsula, but so are other species in its genus: the best way to distinguish it from its non-endangered relatives is to look for the simple, unbranched hairs and the lack of glands below the inflorescence.

Tiburon Paintbrush has yellow flowers often turn reddish after pollination. Although it has green or purplish leaves and can photosynthesize, It is a kind of parasite that survives by attaching to another plant’s roots.

It is a serpentine endemic: all known populations of the species are growing on this type of rock outcrop, in dry sites in grassland. As such, it has never been widespread. Once known only from two or three populations on the Tiburon Peninsula in Marin County, this plant has subsequently been discovered to grow elsewhere, including the GGNP, where it can be found in small numbers on the serpentinite rock plateau south of the Nicasio reservoir. This area is part of an unusual management strucutre: the land is owned by the GGNP but managed by the Point Reyes National Seashore. At the same site are other rare plants including Hesperolinon congestum, the Marin Dwarf-Flax.

The Tiburon Paintbrush’s numbers appear to be constant, but small. In 1995, the species was protected as threatened under the federal Endangered Species Act. Ongoing threats to its existence come from the area’s cattle-grazing regime, fire, or natural causes. As a hemi-parasitic species the health of its host(s) are also important.

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Conservation Action Item

Habitat Restoration:
The Tiburon Paintbrush exists in small populations and their habitat is slowly disappearing.

The grasslands are slowly being taken over by invasive scrubs and other invasive species. Help protect their fragile environment by volunteering with Marin County Parks. In their lands Marin County Parks holds at least 6 of the last remaining populations of the endangered flower and they host restoration days that keep those populations, as well as other precious habitat, healthy.

Big Year Competitors have reported 1 sighting and taken 2 actions to help this species recover so far this year.


  • None scheduled

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