Fremont Cottonwood  Populus fremontii
NATIVE

This woody tree which is  found in watersheds, stream banks, and grasslands is common in our area.  This tree is well known for its ability to grow quickly.  When the wind blows through the leaves it makes a sound like running water.  The leaves have a characteristic spade shape.  These trees can grow to 35 meters.  They are the largest trees in this area.  Male and female are separate trees.  The female tree blooms March to April and has cottony seeds.

Northern California Black Walnut Juglans californica
NATIVE

This native tree is found locally along streams, canyons and  foothills.  The nut is used in  cooking.  The leaves give off an aromatic scent. The males have 2-3 inch catkin, and female trees have inconspicuous flowers that blooms April to May.  The black walnut is different from the English walnut that is common in California.  In most of the commercial groves,  an English walnut is grafted to the root structure of the native black walnut because the native species is more resistant to soil fungi.  

Arroyo Willow      Salix lasiolepis
NATIVE

This native tree is found  in the wet soils along waterbeds, and in valleys, foothills and mountains.  It is also known as a white willow because it has light colored bark and leaves with whitish lower surfaces.  Some varieties of willow bark were used by Native Americans to help reduce fever and pain.  The leaves are simple, about five inches long, irregularly lancolate, and have entire rolled-under margins.    Arroyo Willows are bushy trees that don’t exceed 4 meters in Stivers lagoon, but can reach as high as 10 meters.   It produces yellow flowers during the spring that grow on bunches of stems called catkins.  Willows are found growing in close proximity to the water’s edge.  Birds and other animals use these trees as nesting and feeding places.

Red or smooth willow  Salix laevigata

NATIVE

This stream-side plant grows as a shrub or tree up to  9 meters.  The flowering catkins appear along with and after the new leaves.  The roots of the trees help to stabilize the banks of the creek.     The young stems are reddish. The lower part of the leaf  is wider than the tip of the leaf.

Sandbar Willow  Salix hindsiana

NATIVE

Willows are difficult to key out.  Some taxonomists consider S. hindsiana as the same species as S. exigua.  However, in Stivers Lagoon there is a difference in leaves.  S. hindsiana differs from S. exigua in that the leaves are not hairy on the top of the leaf, only the bottom.  Leaves of the sandbar willow are greener than the grayish color leaf of the narrow leaved willow. 

Narrow-leaved Willow  Salix exigua

NATIVE

New branches are grayish, and  leaves have a furry feeling.  Leaves are very narrow compared to other willows in the area.  The trees grow 2-4 meters. The catkins are borne on separate male and female trees about 1-4 cm in length around March to May.  Narrow-leaved willows grows along the banks, especially near Mission Creek. 

Big-Leaf Maple  Acer macrophyllum 

NATIVE

This tree can be seen  along the meadow side of Muskrat Creek.   The trees can grow 20-25 meters.  Leaves have a characteristic maple look, divided into 3-5 parts.  Clusters of greenish flowers developing into winged fruits that are produced April to May. 

Coast Live Oak  Quercus agrifolia

NATIVE

Coast live oak is an evergreen tree which grows to 10-25 meters tall.  It has a broad, dense crown and spreading branches.  The mature bark is gray and shallowly furrowed.  Leaves are oblong to oval, cupped with toothed margins.  Clusters of rusty hairs may be seen  on the veins on the back of the leaf.    Acorns are narrowly conical and mature in one year.  The trees on the outskirts of Stivers Lagoon were planted.  They are native to this area, but may not been endemic in  the lagoon area.

Holm Oak  Quercus ilex

NON-NATIVE

Holm Oaks are evergreen, originating in the Mediterranean region where they form large forests..  This patch of oaks is at the fringes of Stivers Lagoon, so it probably grew from a seed brought by a squirrel or bird.  There are no Quercus ilex within the lagoon.