Redwood Sorrel

Plant Life

Midpen is home to a great variety of plant communities and biomes. Though all of the preserves contain a diversity of plant species, there are a few unique biomes within Midpen's preserves that we would like to highlight:

  • 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.

Plant Species Spotlight

Get an in-depth look into some of the most iconic and unique plant species that can be found in Midpen preserves. Click on a species to learn more about its habitat and defining features. 

photo of Red Maid flower

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.

Rare Plants

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 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


Hundreds of species of plants bloom in Midpen's preserves from early spring to the later winter months — basically year round! Wildflowers are typically found in sunny grassland habitats, but can also be found in a variety of other habitats. For example, trillium, violets, and redwood sorrel are all flowers that bloom in the redwood forest understory. 

photo of a Douglas Iris

A simple color photograph guide with two selected features showcasing the species—usually flower and whole plant or leaf. This guide was developed for use at Midpen's Annual Wildflower Survey at Sierra Azul Open Space Preserve. It features the 100 most common flowering species seen during the wildflower surveys.

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