FWS Focus

Overview

Characteristics
Overview

Tiburon paintbrush is a semi-woody flowering plant in the snapdragon family that can grow up to two feet tall. It flowers along an upright stalk with the densest blooms at the top, which gives it the characteristic paintbrush appearance. Tiburon paintbrush flowers are usually yellow, but can be found in yellowish-pink and sometimes red.

Tiburon paintbrush will opportunistically parasitize the roots of other flowering plants such as yarrow to absorb more water and minerals, and when doing so grows more vigorously.

This species is native to California and is currently found in seven sites across Marin, Santa Clara and Napa counties. Its historical range is thought to be comparable to its current range.

This species was listed as endangered on February 3, 1995.

The plant continues to be threatened by:

  • Off-trail recreation
  • Feral pigs
  • Animal grazing/herbivory and trampling
  • Fire retardant
  • Habitat loss
  • Non-native grasses 
  • Climate change and drought
  • Gravel mining

Scientific Name

Castilleja affinis ssp. neglecta
Common Name
Tiburon Indian paintbrush
Tiburon paintbrush
FWS Category
Flowering Plants
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

Tiburon paintbrush grows in serpentine soil on north to west facing slopes in bunchgrass communities of California at elevations between about 250 and 1,300 feet. It currently has seven known populations: four in Marin County, one in Napa County and two in Santa Clara County. In Marin County, it can be found at Nicasio Ridge and at three sites on the Tiburon Peninsula. The Napa County population is in Newell Open Space Preserve and on private land. It can be found in Santa Clara County at Paintbrush Canyon and Paintbrush Hill.

Grassland

Land on which the natural dominant plant forms are grasses and forbs.

Rural

Environments influenced by humans in a less substantial way than cities. This can include agriculture, silvaculture, aquaculture, etc.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

Tiburon paintbrush stands from 1 to 2 feet tall and has a sparse covering of soft, spreading hairs. The lance-shaped leaves are 0.8 to 1.6 inches long and have zero to five lobes. The floral bracts are yellowish and sometimes red-tipped. The flowers grow along an upright stalk, most densely at the top of the stalk, and range from creamy yellow to red. Individual flowers are 0.7 to 0.8 inches long. 

Characteristic category

Similar Species

Characteristics
Similar Species
Characteristic category

Life Cycle

Characteristics
Reproduction

Tiburon paintbrush is a perennial that flowers from April to June, when it is pollinated by hummingbirds and bees. Seeds are shed in June and July, and the species dies back to its woody base in July and August. New growth from the woody base begins in December or January. Seeds may remain dormant in the soil for several years. Seed germination occurs in January or February and seems to be induced by leaching and low temperatures of between 45 to 59 degrees Fahrenheit.

Geography

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