Cirsium fontinale var. fontinale (Flowering Plants)

Species Description

The Fountain Thistle is a beautiful plant in the aster (Asteraceae) family. It is restricted to serpentine seeps. It has very large, gray-green, spine-tipped leaves at the base of the plant and sends up a leafy flowering stalk in late summer. The pinkish flower heads are at the top of this flowering stalk surrounded by spiny structures (phyllaries). The flower heads are initially nodding before straightening up to ripen its seeds. The plant with flowering stem can be up to 2 dm tall, which distinguish it from the most similar thistle in its range, the brownie thistle (Cirsium quercetorum) that is compact and low to the ground.

The Fountain Thistle is “endemic” to San Mateo County, which means it cannot be found naturally anywhere else in the world. Historically the Fountain Thistle was known to have five occurrences in San Mateo County. Two occurrences have become lost in the last 10 years. However in the last 5 years 2 new populations have been discovered, one on private property and one on public land belonging to Redwood City, CA.

A combination of threats has caused the population to decline in recent years. Some of these threats are urbanization, alteration of local hydrology, dam construction in the 19th century, highway construction , and non-native plant invasion.

The type locality—the geographic area where the species was originally identified—suffered with the construction of Highway 280 and the Highway 92 interchange. In 1995, the Fountain Thistle was protected as endangered under the Federal Endangered Species Act.

Today the species still faces obstacles to recovery. Invasive species such as pampas grass (Cortaderia jubata) are overtaking the Fountain Thistle’s natural habitats. Although more needs to be done to control invasive plants within the plant’s habitat, the San Francisco Peninsula Watershed staff have a plan in effect that is working on this problem on their lands.

Conservation Action Item

Restore Fountain Thistle habitat:
Volunteer in San Mateo County

A dedicated group of local ecologists have been struggling to keep invasive, colonizing weeds from displacing the Fountain Thistle from its remaining habitats. You can help the Fountain Thistle by volunteering for habitat restoration near the species’ remaining populations.

Big Year Competitors have reported 7 sightings and taken 6 actions to help this species recover so far this year.

Trips

• Fountain Thistle Walk and Restoration
  Saturday, 12 Jun 2010, 10:00 - 15:30 Pacific Time (US & Canada)
• A Fantastic Fountain Thistle Recovery Work Party
  Saturday, 23 Oct 2010, 09:00 - 12:00 Pacific Time (US & Canada)