A great variety of environments, wildlife habitats, and plant life can be found in the open space preserves. All of the preserves have diverse plant species but many have distinct environments, including those described here. We hope you might visit one of these preserves to enjoy particular types of surrounding.

  • Redwood Forest - Purisima Creek Redwoods and El Corte de Madera Creek Open Space Preserves.
  • Chaparral - Sierra Azul, Pulgas Ridge, Skyline Ridge, and El Sereno Open Space Preserves.
  • Salt Marsh - Ravenswood Open Space Preserve and Stevens Creek Shoreline Nature Study Area.
  • Oak Woodland - Many of the preserves offer a sampling of oak woodlands.
  • Meadow, Grasslands - Windy Hill, Russian Ridge, Long Ridge, Fremont Older, and many other preserves.

Some of the more rare plants found on open space preserves are listed below. Note that these plants are not officially listed as "endangered" or "threatened" under either state or federal laws, but they are rare and recognized as rare by the California Native Plant Society.

  • Kings Mountain manzanita (Arctostaphylos regismontana): This shrub blooms in March and April.
  • Western leatherwood (Dirca occidentalis):  A small tree that blooms in February.
  • Choris' popcorn flower (Plagiobothrys chorisianus var. chorisianus): This wildflower blooms from April and June.
  • Santa Clara redribbons (Clarkia concinna ssp. Automixa):  Another wildflower that blooms from April through July.

For a more complete list of plants that can be found on District preserves, visit the Natural Resources DataBase.

Plant of the Month

Removing invasive plants and weeds is a large part of the restoration work that takes place in our preserves. This can be challenging, since some invasive species look similar to California natives. Become a citizen scientist and help us by recording your observations in the free iNaturalist app.

March - Poison Oak and English Ivy

Poison Oak leaves change from green to red throughout the season. © Jill MatsuyamaPoison Oak (Toxicodendron diversilobum)

  • Native Plant
  • Leaves: 3 lobed, shiny/oily, change in color from green to red from spring to summer
  • Bloom period: March – June
  • Grows on ground in clearings, forest or fields. May also hang down from trees.
  • Urushiol oil is what causes a rash and itching in most people. It is on all parts of the plant at all times of the year.
  • "Leaves of three - leave it be!"

English Ivy (Hedera helix)Invasive English Ivy

  • Non native - introduced into North America in early colonial times as an ornamental
  • Evergreen vine or shrub
  • It has been planted to control soil erosion in many parts of the United States because of its habit of rooting at the leaf nodes along the stem
  • English ivy can alter natural succession patterns in forests by inhibiting regeneration of understory plants including wildflowers, shrubs and trees
  • Replaces species used by native wildlife