Pleasanton Ridge Regional Park

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         (662 plants)
Thanks to the East Bay Regional Park District for this list.

    
Alaska Piperia
Piperia unalascensis
  • CA Bloom Apr - Jul
  • This erect orchid has many small green flowers.
  • Flowers have a nectar spur, enticing pollinators to rub against the flower's reproductive parts.
  • Widespread, it's found from Alaska to the southwest US, as well as in eastern Canada.
  • It does well in dry woodland and gravelly stream banks.
  • CA native



Orchid flowers are mostly green and give off a sweet smell at night, attracting pollinating moths.

Basal leaves are up to 6 inches long, fairly wide, and have parallel veins.

Flowers are small and form a slender column at the top of the plant.
Alkali Bulrush
Bolboschoenus maritimus
  • CA Bloom Aug - Sep
  • Flat, narrow stems to about four feet tall.
  • Found near the edge of salt water.
  • Widespread in California and around the world.
  • CA native



Flowers dark brown with tan bristles.

Flowers group in the joint of flat stems.

Stands erect with noticeable brown flowers
Almond
Prunus dulcis
  • CA Bloom Feb - Mar
  • White flowers cover the tree in a showy display in the spring.
  • Grows to 15 feet with a rounded shape.
  • Alternate leaves are deciduous.
  • Not CA native



Narrow leaves grow to about 5."

Covering opens up at maturity.

Pink blossoms in the spring - this tree is widely cultivated in the central valley.
Alum Root
Heuchera micrantha
  • CA Bloom May - June
  • Alum Root sends wispy stems two feet in the air, supporting dozens of tiny white or pink flowers.
  • Leaves at the base of plant are shaped like mittens.
  • Found in wet areas, often near moss.
  • CA native



Tiny flowers on leafless wispy stems about 2 feet tall.

Leaves connect to the base of the plant on long stalks. They're fuzzy and roundish.

Leaves form a thick basal cluster, with tiny flowers appearing to be suspended in air above them.
American Brooklime
Veronica americana
  • Height to 1 ft.
  • CA Bloom Jul - Aug
  • Blue or violet 4-petaled flowers
  • Opposite leaves
  • Round stems
  • Grows in fresh-water wetlands, such as stream banks
  • Stem runs along the ground, up to 2 feet long.
  • CA native



Look for 4 petals and opposite leaves with a round stem. Green center guides in pollinators.

4 pale-blue petals with 4 green sepals behind them.

Opposite leaves up to 3 inches long. Flowers in groups at the end of stalks.
American Dogwood
Cornus sericea
  • CA Bloom Jun - Aug
  • White 4-petaled flowers in round bunches
  • White berries
  • Medium tall shrub grows to 12 feet
  • Opposite leaves, green above and hairy grey below
  • Found in damp areas
  • CA native



Opposite leaves, strong veins, pointed tips.

Showy clumps of flowers turn into white berries.

4-petaled white flowers grow in clumps at the end of stems.
American Vetch
Vicia americana
  • CA Bloom May - Jun
  • Flowers with pink, violet and white parts.
  • Tendrils, modified leaves, allow the plant to climb on other plants.
  • Alternate compound leaves.
  • A widespread understory plant.
  • CA native



Purple pea-like flowers

Alternate compound leaves.

Vine grows to a foot long. One inch pea pods for fruit.
American Vetch (1)
Vicia americana ssp. americana
  • Height 1 - 2 ft.
  • CA Bloom May - Jun
  • Flowers with pink, violet and white parts.
  • Tendrils, modified leaves, allow the plant to climb on others.
  • The vine stem can grow to 4 feet long, but the plant is generally under 2 feet tall.
  • Alternate compound leaves.
  • Widespread understory plant.
  • CA native



Small but bright flowers

Lots of small compound leaflets.

Long thin leaves and purple flowers make this a vetch.
Annual Beard Grass
Polypogon monspeliensis

Annual Beard Grass is topped by large, fluffy spikes. They're framed by flat, rough, green leaves to 8" long.

Soft, dense spikelets are green until they mature. There are lots of spikelets in the spike, each producing 3 awns.

Long awns let light through around the edge but the center is opaque.
Annual Blue Grass
Poa annua


Bright green or yellow-green leaves are soft, generally flat and come to a blunt point at the tips.

Like all Bluegrasses, the inflorescence is open and spikelets have no awns. Florets are membranous.

Annual Blue Grass grows quickly in disturbed areas. Plants are small but have many leaves.
Annual Hairgrass
Deschampsia danthonioides


This meadow grass has spreading spikelets with awns, giving it a fuzzy appearance, thus Hairgrass. Spikelets sometimes have purple tips.

Hairgrass grows singly or in loose clumps. Spikelets grow on narrow, spreading, ascending branches.

Two large bracts surround 1-3 florets. Each floret has a long awn that bends in the middle.
Annual June Grass, Bristly Koeleria
Koeleria gerardii
  • CA Bloom Apr - Jul
  • Not CA native




  • Annual Stinging Nettle
    Urtica urens
    • CA Bloom Jan - Apr
    • Also called Dwarf Nettle, this plant grows to about 2 feet tall.
    • Stinging nettles, in general, produce a stinging sensation when touched. However, EFlora says that this specie's sting is not very strong.
    • Found in shady areas.
    • Not CA native



    Leaves are hairy, dark green, have large teeth, and end in a point.

    Leaves are opposite. Veins make indentations in the leaves.

    Small green flowers look like little balls.
    Annual Vernal Grass
    Anthoxanthum aristatum
  • CA Bloom May - Jun
  • Not CA native




  • Aquatic Pygmy Weed
    Crassula aquatica
    • CA Bloom Mar - Jun
    • This tiny succulent plant grows in areas that are frequently submerged in water.
    • Pink flowers have four petals and are less than 1/4" wide.
    • Leaves are opposite, succulent, thin and pointed.
    • Found in wetlands across California.
    • CA native



    A succulent with tiny short pointed leaves less than 1/4 inch long.

    Likes to be submersed in water (salt or fresh). Grows erect when exposed to air.

    Tiny pink flower less than 1/4 inch wide. Leaves can be red as well as green.
    Arroyo Lupine
    Lupinus succulentus
    • Grows to 3 ft. on erect, sparsely hairy stems.
    • CA Bloom Feb - May
    • This annual flower produces 6" clusters of purple pea flowers.
    • Wide-tipped leaflets grow on long (2-6") stalks.
    • It is abundant in open or disturbed areas, and is often seeded on road banks.
    • CA native



    Look for radial leaflets that are wider near the tip. Their fleshy top feels rubbery.

    Here's a closeup of the flower. The yellow pistil is just sticking out of the right-hand keel. The left part is the banner.

    Stacks of whorled flowers have white banner spots that turn magenta with age.
    Arroyo Willow
    Salix lasiolepis
    • Height 7 - 35 ft.
    • CA Bloom Feb - May
    • This is the most common willow in California.
    • It's deciduous and is found near water.
    • Look for narrow leaves that are wider near the tip than at the base.
    • CA native.



    Leaves are about 5 inches long, smooth-sided and narrow. They're pale/hairy underneath, and wider near the tip than near the base.

    Classic pussies with yellow stamens. The buds are fused together (not overlapping) before they open.

    This willow has many trunks, sometimes growing as a tree, and sometimes as a tangled shrub.
    Australian Fireweed
    Senecio glomeratus
    • CA Bloom Apr - Sep
    • Yellow composite flowers group at the top of a branched 6 foot plant.
    • Leaves are alternate and deeply lobed.
    • Found in disturbed sites below 1,000 feet, generally near the coast.
    • Not CA native
    • Moderately Invasive


    Composite flowers group at the top of the stem. They have no "petals" ( ray flowers).

    Leaves clasp the stem, grow to about 6 inches, and are deeply lobed.

    Grows to 6 feet or so, with lots of flowers near the top of the stem.
    Baby Blue Eyes
    Nemophila menziesii var. menziesii
    • CA Bloom Mar - Jun
    • Distinctive with blue petals, white center and black dots in the center.
    • Opposite leaves are lobed, especially near the base.
    • Found in grasslands and woodland.
    • CA native



    Pale blue to dark blue petals.

    Five separate blue petals with a white center, usually with black dots.

    Grows a couple of inches above the ground, with opposite, lobed leaves.
    Baneberry
    Actaea rubra
    • Height 8 in. - 3 ft.
    • CA Bloom May - Jul
    • Baneberry is a shrub that grows to about 3 feet tall.
    • Leaves are coarsely toothed.
    • Bright red or white berries are hard to miss, and warn animals that they're poisonous.
    • White showy flower clusters.
    • Found in shady, moist woodland.
    • CA native



    Leaves have deeply toothed margins. Poisonous berries are red or white, with a black dot.

    White showy clusters of flowers stand out on their own stalks. Each flower has many long stamens.

    Leaves are compound and sharply toothed. Leaves and flowers are on separate stalks.
    Beaked Hawksbeard
    Crepis vesicaria
  • CA Bloom Feb - Oct
  • Yellow flower
  • Many petals
  • Alternate, basal leaves
  • Disturbed
  • Not CA native


  • In the Dandelio sub family. Weedy Hawksbeard has many flat-tipped yellow "petals"

    When viewed from behind, the flower is supported by separate green leaf-like phyllaries.

    Many flowers attach to a single stem. Traditional "ragged" dandelion leaf.
    Beaked Hazelnut
    Corylus cornuta
  • CA Bloom Feb - Mar
  • Tiny petals
  • Alternate leaves
  • Streambanks slopes
  • CA native




  • Bearded Clover
    Trifolium barbigerum
    • Height to 1 ft.
    • CA Bloom Feb - May
    • Brown, pink, violet, white flower
    • Irreg petals
    • Alternate leaves
    • CA native




    Bearded Sprangletop
    Leptochloa fusca ssp. fascicularis
  • CA Bloom Jun - Oct
  • CA native




  • Beardless Wild Rye
    Elymus triticoides


    This rye has 2-ranked spikelets that connect directly to the stem. There is space between each alternating spikelet.

    Hollow stems (like straws) connect at solid joints. Leaves are about 1/4" wide and a foot long.

    Prominent blue-green leaves are 4-12" long and grow away from the stem. Found in moist habitats with heavy soils.
    Bee Plant
    Scrophularia californica
    • Height 2 - 4 ft.
    • CA Bloom Feb - May
    • Bee plant is tall, with prominent triangular leaves and tiny brownish-red flowers.
    • Small flowers are less than 1/2" across and have a nectar disk to reward pollinating bees.
    • Opposite leaves have stalks that connect to the stem.
    • Found in moist places below 8,000 feet.
    • CA native



    This view of the flower from below shows two rounded petals on top, two side petals, and one folded out like a tongue.

    A square stem supports large, opposite, toothed leaves. This might make you think "Mint" but it's not.

    Bee Plant grows several feet high with opposite, narrow leaves sticking straight out. Flowers are on horizontal stalks near the top.
    Bentgrass
    Agrostis exarata


    Spikelets form a dense, slender column with short stalks. At maturity, the column opens up a bit. Awns are so short you may not notice them.

    Leaf blades are about 1/4" wide and 6" long. The ligule is prominent, membranous and not hairy.

    Leaves mostly ascend from the base of the plant. A long, narrow inflorescence rises above them, turning purple and then brown late in the season.
    Bermuda Grass
    Cynodon dactylon

    Spikelets are tiny (<1/10") and purple. Tight colonies of plants are connected by rhizomes and stolons.

    Two rows of spikelets connect to one side of finger-like branches that all join at the top of the stem.

    The ligule is white and hairy. Leaf blades are short, flat and fleshy.
    Big Leaf Mistletoe
    Phoradendron leucarpum ssp. macrophyllum
  • Shrub
  • Green flower
  • Tiny petals
  • Opposite leaves
  • CA native




  • Big Scale Balsam Root
    Balsamorhiza macrolepis
  • CA Bloom Mar - Jun
  • Yellow flower
  • Many petals
  • Basal leaves
  • Slopes
  • CA native
  • Endangered (CNPS 1B)




  • Big Squirrel Tail Grass
    Elymus multisetus


    Dense inflorescences with long, purplish awns resemble squirrel tails, especially when they mature.

    Here's a closeup of a squirrel tail. It's crowded with spikelets, each producing 8-22 awns!

    Leaves are narrow and long. Found in open, sandy or rocky areas.
    Big Tarweed
    Blepharizonia plumosa
  • CA Bloom Jul - Oct
  • CA native
  • Endangered (CNPS 1B)




  • Big-Leaf Maple
    Acer macrophyllum
    • Height 50 - 100 ft.
    • CA Bloom Apr - May
    • You'll probably notice the maple leaves first; they're large and grow opposite each other.
    • Leaves are green in the summer, yellow in the fall, and absent in the winter.
    • In spring, small greenish-yellow flowers hang in clusters below newly emerging leaves.
    • Big Leaf Maples do well near water and in dappled shade.
    • CA native



    Leaves are quite large, up to 12" wide, with deep indents. No other maple in the U.S. has leaves this big.

    Flower clusters droop from emerging leaves.

    Two winged fruits grow side by side, creating a helicopter-like lift when they're blown away on the wind.
    Bioletti Cudweed
    Pseudognaphalium biolettii
    • CA Bloom Jan - May
    • Flowers are white on the outside and yellow on the inside.
    • Alternate leaves are wide at the base and clasp the stem.
    • Leaves and stem are covered with short fine hair, not sticky but sharply scented.
    • Found in coastal chaparral and in mixed evergreens in the foothills.
    • CA native



    Shiny papery phyllaries surround tiny yellow aster flowers.

    Many tiny brown fruits.

    Grows to 3 feet, sometimes woody at the base.
    Bird's Eye Speedwell
    Veronica persica
    • Height 4 in. - 1 ft.
    • CA Bloom Feb - May
    • This is a small, beautifully marked wildflower.
    • Leaves are opposite and small, often with serrated edges.
    • It's found in disturbed areas, often near agriculture.
    • Not CA native



    The small (1/4"), 4-petaled flower has darker blue, radiant stripes. Notice how the petal sizes vary. 2 purple-tipped stamens and a green tinged center invite pollinators to visit.

    Leaves are opposite. Flowers cluster at the top of the stem. The plant is often recumbent, lying along the ground.

    This beautiful plant is easy to overlook because of its small size, but a pleasure to find.
    Bird's Eyes
    Gilia tricolor
  • CA Bloom Apr - Aug
  • Pink, violet, white flower
  • Five petals
  • Alternate leaves
  • Slopes
  • CA native




  • Bird's Foot Lotus
    Acmispon brachycarpus
    • Height 6 in. - 1 ft.
    • CA Bloom Mar - Jun
    • Yellow flower
    • Pea petals
    • Alternate leaves
    • CA native




    Bird's Foot Trefoil
    Lotus corniculatus
    • Height to 8 in.
    • CA Bloom May - Jul
    • Tiny fruit clusters look like a bird's foot.
    • Short, thin compound leaves make bundles along the stem.
    • Find it in open grasslands, wetlands, and compacted soil along roads and trails.
    • Other Trefoils
    • Not CA native



    Tiny pea flowers cluster at the end of the stem.

    Each plant is small. See fruit pods on the left, compound leaves in the middle, and a flower cluster on the right.

    Colonies of Bird's Foot Trefoil can be prominent in grasslands. It is sometimes vine-like, with prostrate stems up to 20 inches.
    Bitter Cherry
    Prunus emarginata
    • CA Bloom Apr - May
    • White 5-petaled flowers about 1/2" across smell nice.
    • Leaves yellow-green with tightly-spaced veins.
    • A shrub to medium-sized tree.
    • Canyons, slopes, ridges, open woods in nutrient-rich soil.
    • CA native



    3-10 small flowers per cluster, 5 separate petals, long stamens.

    Leaves to 3 inches long with bumpy edges. Red cherries, each with its own stalk.

    Bitter Cherry forms thickets on sunny hillsides.
    Black Cottonwood
    Populus trichocarpa
    • CA Bloom Feb - Apr
    • A large riparian tree with alternate leaves
    • Leaf stems are round (Fremont Cottonwood's is flattened).
    • Widely distributed in California, except the central valley.
    • CA native



    Leaf tops are glossy dark-green. Undersides are pale. Leaves are long and pointed, with small teeth on the edge.

    Alternating secondary veins connect to a central one.

    Grows near running water. Trunks get very large, and the tree height often exceeds 100 feet.
    Black Mustard
    Brassica nigra
  • CA Bloom Apr - Jul
  • Yellow flower
  • Four petals
  • Alternate leaves
  • Not CA native
  • Moderately Invasive




  • Black Oak
    Quercus kelloggii
    • CA Bloom May - Jun
    • This majestic tree is a keystone species, providing habitat and food to many animals.
    • Black Oak is the only deciduous California oak with bristle-tipped lobes.
    • CA native



    Deciduous leaves have pointy lobes with bristles at their tips. They're darker on top than on the bottom.

    In spring, early leaves are red and velvety. Catkins of male flowers hang from leaf axils, getting ready to disperse pollen on the wind.

    A stout trunk supports many heavy, ascending branches. Branches decay and hollow out, providing den and nesting sites.
    Black Sage
    Salvia mellifera
  • CA Bloom Mar - Jul
  • Violet, white flower
  • Irreg petals
  • Opposite leaves
  • CA native


  • Mint flowers and leaves in whorls around the stem.

    Seed groups s become woody.

    Basal leaves much longer than wide, with a strong central vein. Flowers in whorls around the upper stem.
    Blackwood Acacia
    Acacia melanoxylon
    • Height 50 - 100 ft.
    • CA Bloom Feb - Mar
    • This acacia tree has twisted reddish-brown pods.
    • The trunk has high levels of tannin, which causes dark stains when people handle it (thus Blackwood).
    • Generally found in coastal disturbed areas.
    • Not CA native
    • Somewhat Invasive


    Pale yellow spherical flowers show many stamens. These develop into reddish-brown pods.

    Mature leaves are generally wide but occasionally have divided fern-like tips. Young leaves are divided too.

    Blackwood Acacia grows to be a substantial tree.
    Bloomer's Buttercup
    Ranunculus orthorhynchus var. bloomeri
  • CA Bloom Mar - May
  • Yellow flower
  • Five petals
  • Alternate, basal leaves
  • CA native




  • Blow Wives
    Achyrachaena mollis
    • Height 2 in. - 2 ft.
    • CA Bloom Apr - May
    • This eye-catching bright-white flower is not a flower at all. As you look closer, you'll see that the "petals" are actually the flat scales of a seed head.
    • A California endemic, this plant grows natively nowhere else in the world.



    Here is the classic Blow Wives look. Flat, scaly pappus forms a wind parachute for each seed.

    Yellow or orange ray florets point straight up. Inside them, many disc florets grow without petal-like rays.

    Leaves are narrow and grow up to 6" long. They're erect and fuzzy.
    Blue Dicks
    Dipterostemon capitatus
    • CA Bloom Feb - Apr
    • Look for a tight bunch of 6-petaled flowers on a single stem, about 1 foot tall.
    • Flowers can be purple, pink or white.
    • This common springtime flower is widespread where there is sun.
    • Compare to Ookow
    • CA native



    A tight bunch of 6-petaled flowers appears at the top of a tall, wavy stalk.

    The centers of the flowers feature a forked, white sheath that surrounds yellow-tipped stamens.

    Long, narrow leaves grow from the base of the plant. Below, the roots connect to food-storing corms.
    Blue Elderberry
    Sambucus mexicana
    • CA Bloom Mar - Jul
    • A large shrub with clusters of white flowers, plus compound leaves indicate an Elderberry.
    • Berries are black but appear blue because of a waxy covering.
    • Grey bark with vertical furrows.
    • Common on stream banks and open places in forests.
    • CA native



    White flat-topped clusters of flowers are easy to spot.

    Berries with a waxy covering makes them look powdery.

    Compound leaves with 5 - 9 toothed leaflets.
    Blue Fescue
    Festuca idahoensis


    Found in dry, open or shady places, Blue Fescue may appear bluer than plants around it.

    Spikelets are about 1/2" long. There's enough room between spikelets to see wavy branches.

    Spikelets are flattish, with 2-ranked florets. They're held close to the stem until mature. Awns are thread-like.
    Blue Field Gilia
    Gilia capitata
  • CA Bloom Feb - Apr
  • Blue, violet, white flower
  • Five, no petals
  • Alternate, basal leaves
  • Coastal
  • CA native




  • Blue Fiesta Flower
    Pholistoma auritum var. auritum
    • CA Bloom Mar - May
      This vine is covered with recurved stiff hairs that stick to passersby. The stem breaks easily.
    • Leaves are opposite near the base and alternate higher up the vine.
    • It's common in coastal and Sierra foothills, primarily south of the Bay Area.
    • CA native



    This bright flower is about 1" across, with a pale ring around a dark throat.

    Sepals are pointed and hairy, alternating bent forward and backward.

    Leaf stalks have wings on their sides and wrap around the stem. Leaves are long with lots of narrow lobes that stick out sideways.
    Blue Gum
    Eucalyptus globulus
    • Height to 200 ft.
    • CA Bloom Oct - Mar
    • Flower nestled between stem and leaf.
    • Leaves long, thin and dark green.
    • Common, found in disturbed areas.
    • Not CA native
    • Somewhat Invasive


    Flower has many white stamens surrounding a central knob, and smells of honey.

    Mature leaves are narrow and curved, growing to a foot long. Woody fruits with 5 notches, grow to 1 inch across.

    Heavy trunks with bark that peals in large strips.
    Blue Oak
    Quercus douglasii
    • Height 20 - 65 ft.
    • CA Bloom Mar - May
    • Blue-green leaves with wavy edges, plus corn flake bark, are quick way to identify this oak.
    • Leaves are relatively small and sparse, allowing it to tolerate more sun and dryer places than other California deciduous oaks.
    • CA native. Found only in California.



    Leathery blue-green leaves often have shallow lobes. They have a short petiole (stalk) and are generally 2 - 3 inches long.

    Bark is pale and checkered by medium-size cracks. It reminds me of corn flakes.

    This moderately sized oak has a heavy trunk and branches. It's common in dry, hot places that have some water.
    Blue Witch
    Solanum umbelliferum
    • CA Bloom Jan - Jun
    • Look for a pentagon-shaped flower with a bright yellow center.
    • Branches and leaves are quite hairy.
    • Green fruits turn purple when ripe.
    • This distinctive shrub is widespread in chaparral and oak woodlands.
    • CA native



    Blue Witch flowers are lavender or blue, pentagon-shaped, and have a yellow center.

    Leaves are hairy and smooth edged. Flowers sport green spots at the base of their petals.

    Blue Witch is a small shrub that grows to 3 feet. Every part of it is poisonous to eat.
    Blue-Eyed Grass
    Sisyrinchium bellum
    • Height 1 - 2 ft.
    • CA Bloom Mar - May
    • This is not a grass but an iris.
    • At the top of each stem are violet flowers with darker purple lines leading to a yellow center.
    • It's common in open, usually moist areas.
    • CA native. Endemic to the California Floristic Province.



    Beautiful 1/2" wide flowers have blue to violet petals and a golden yellow center to guide pollinators in.

    Leaves are grass-like, narrow with parallel veins.

    The ovary is below the flower and, if pollinated, develops into a capsule-like fruit.
    Bog Yellowcress
    Rorippa palustris ssp. palustris
  • CA Bloom Apr - Jun
  • Yellow flower
  • Four petals
  • Alternate leaves
  • CA native




  • Box Elder
    Acer negundo
    • Height 25 - 66 ft.
    • CA Bloom Feb - Mar
    • Opposite leaves
    • Streambanks
    • CA native




    Bracken Fern
    Pteridium aquilinum var. pubescens
    • Bracken Fern's overall shape is a large triangle, which is easy to spot.
    • It's green in the spring and brown in the fall and winter.
    • It grows to four feet tall.
    • Widespread and common, it's found in shaded forest and on open hillsides.
    • CA native



    Bracken Fern frond segments are long at the base and quite short near the top, creating an overall triangle shape.

    Segments have regular rounded lobes. The similar Sword Fern has a "thumb" near its midrib.

    New growth forms in a fiddlehead, and then opens up.
    Bracted Allocarya
    Plagiobothrys bracteatus
  • CA Bloom Apr - May
  • White flower
  • Five petals
  • Alternate, basal leaves
  • CA native




  • Branched Indian Clover
    Trifolium dichotomum
  • CA Bloom Mar - May
  • Black, brown, pink, white flower
  • Irreg petals
  • Alternate leaves
  • CA native