Seeds were put into long-term storage at the National Seed Storage Laboratory in 1988 and another collection will be made in 2002 in collaboration with the U.S. Fish & Wildlife Service.

An in-depth demographic study and reintroduction attempt was performed from 1990-1997. The natural population significantly and progressively increased in abundance and density between 1990 and 1994, then began a decline that lasted through 1997. In general, high density and high yield (reproductive plants produced from previous year's nutlet production) were associated with average or below-average years of precipitation while low densities and yield were associated with above-average rainfall years. During the entire study period, survivorship to reproduction remained fairly high and consistent, indicating that population trends were due to variations in nutlet production and the influence of cryptic factors that operate in the seed bank. The experimental population differed in several critical respects from the natural population, including low germination, low and variable survivorship, low nutlet production and perhaps high nutlet mortality. These features reduced the potential for self-sustained growth in the experimental population, which is likely to be extirpated within the next few years. This failure to produce a self-sustaining population of Acanthomintha duttonii emphasizes the urgent need for in situ preservation of self-sustaining natural populations of serpentinite species. (Pavlik and Espeland 1998).

An in-depth demographic study and reintroduction attempt was performed from 1990-1997. The natural population significantly and progressively increased in abundance and density between 1990 and 1994, then began a decline that lasted through 1997. In general, high density and high yield (reproductive plants produced from previous year's nutlet production) were associated with average or below-average years of precipitation while low densities and yield were associated with above-average rainfall years. During the entire study period, survivorship to reproduction remained fairly high and consistent, indicating that population trends were due to variations in nutlet production and the influence of cryptic factors that operate in the seed bank. The experimental population differed in several critical respects from the natural population, including low germination, low and variable survivorship, low nutlet production and perhaps high nutlet mortality. These features reduced the potential for self-sustained growth in the experimental population, which is likely to be extirpated within the next few years. This failure to produce a self-sustaining population of Acanthomintha duttonii emphasizes the urgent need for in situ preservation of self-sustaining natural populations of serpentinite species. (Pavlik and Espeland 1998).

Only known from a narrow, 10 km stretch in San Mateo County in the San Francisco Bay area of California. Only 2 small populations are known extant. Historically, the species was found scattered infrequently throughout this area, but most populations are believed to have been destroyed by urban and associated highway development. The 2 small remaining populations are located in a county park and adjacent to the park on land managed by the San Francisco Water Department. However, they remain threatened by urban development, vehicles and vandalism.

The numbers of this annual herb vary by year, from over 53,000 in 1994 to a low of 5,289 in 1997 (Pavlik and Espeland 1998).

An in-depth demographic study and reintroduction attempt was performed from 1990-1997. The natural population significantly and progressively increased in abundance and density between 1990 and 1994, then began a decline that lasted through 1997. In general, high density and high yield (reproductive plants produced from previous year's nutlet production) were associated with average or below-average years of precipitation while low densities and yield were associated with above-average rainfall years. During the entire study period, survivorship to reproduction remained fairly high and consistent, indicating that population trends were due to variations in nutlet production and the influence of cryptic factors that operate in the seed bank. The experimental population differed in several critical respects from the natural population, including low germination, low and variable survivorship, low nutlet production and perhaps high nutlet mortality. These features reduced the potential for self-sustained growth in the experimental population, which is likely to be extirpated within the next few years. This failure to produce a self-sustaining population of Acanthomintha duttonii emphasizes the urgent need for in situ preservation of self-sustaining natural populations of serpentinite species. (Pavlik and Espeland 1998). Seeds were put into long-term storage at the National Seed Storage Laboratory in 1988 and another collection will be made in 2002 in collaboration with the U.S. Fish & Wildlife Service.

The county park land is managed by San Mateo County. Nearby fencing helps restrict unauthorized vehicular access.

Studies of nutlet mortality and germination in the seed bank.

Additional collection of seeds to achieve genetic diversity representation in storage (planned for summer 2002).

Small areal extent Development Vandalism Potential change in local environmental conditions from nearby development disturbance by hikers and mountain bikers.