12 Easy Grasses

Login      
         (12 plants)


Here's a guide to get you started with grasses - 12 distinctive grasses you'll see fairly frequently in Marin County.

Once you learn how to identify these, you'll have an eye for patterns to look for as you investigate more grasses.

Thanks to Phil Greer for providing information for this guide.

Have fun!

    
Grass Family





Rattlesnake Grass
Briza maxima

This grass is easy to identify, with its nodding spikelets on long, thin stalks that wave in the breeze. They're oval, papery, and have no awns.

Spikelets start pale green and become tan with age. They're wide, fairly flat, and appear woven, with 12-20 florets. They look and shake like the tail of a rattlesnake.

Notice the purple shoulders ( glumes) on these developing spikelets. Leaves are flat and fairly wide.
Wild Oats
Avena fatua

Spikelets hang down in an open, branched inflorescence. They form an upside-down V - a hallmark of the oat genus.

Spikelets have long glumes, encompassing 2 or 3 florets and form a downward V. Notice the hairy base. Awns are over an inch long and are bent.

Leaves wrap around the stem and then open up into a flat blade that grows to about 16" long. Ligules end in a sharp point.
Dogtail Grass
Cynosurus echinatus

Dense, awned spikelets are generally packed on one side of the stem in a short cluster.

As spikelets mature, the awns point in all directions. Some spikelets have 1-5 fertile florets and others have 6-18 infertile florets.

Leaves are prominent and rough.
Velvet Grass
Holcus lanatus

Soft, arching spikelet clusters are fun to see and touch in the spring.

Spikelets emerge in striking, dense, dark purple clusters. Over time, the clusters open up and the color fades to a whitish green.

Unfortunately, Velvet Grass dominates many damp meadows and disturbed places, choking out native species.
Foxtail Barley
Hordeum murinum ssp. leporinum

This common Barley has a dense spike of spikelets with long awns pointing in all directions.

Three spikelets attach at each node on the stem. The outer spikelets are longer and are male only.

This single-stem grass grows in large colonies, with showy spikes that turn purple with age.
Purple Needlegrass
Stipa pulchra


Purple Needlegrass has an open inflorescence and long awns. It has only one floret per spikelet.

Spikelets are purplish. Awns are needle-like and about as long as your pinkie (1.5 to 4"). Awns bend twice when they're mature.

The weight of the spikelets and the length of their awns causes the grass to bend at the top and wave in the wind.
Ripgut
Bromus diandrus

Ripgut develops a distinctive nodding form. Florets have very long (2") awns with barbs that won't let you rub them backwards.

Ripgut grows vigorously throughout the rainy winter, maturing in the summer. Spikelets are narrow and long, with 5-8 overlapping florets.

Leaf blades and sheaths are hairy and rough. Blades roll inward when dry. Like other bromes, the sheath shows a V neck at the top.
Panic Veldtgrass
Ehrharta erecta

Dark-green leaves are wide and grow to 6" long. Parallel veins are prominent and the margins are often wavy.

An open inflorescence rises above the leaves, 2-8" tall.

Many oval spikelets cling to branching stalks. The spikelets are small, less than 1/4" long.
Italian Ryegrass
Festuca perennis

This grass stands erect and has spikelets alternating up the stem, 2-ranked.

Notice how each spikelet fits in an indentation in the stem. Mature anthers show here, spreading their pollen on the wind.

Spikelets have quite a few florets. Awn length varies - long here and absent in the previous picture.
Blue Wild Rye
Elymus glaucus ssp. glaucus


This grass can grow to 5 feet tall and has a tight spike of spikelets at the top of the stem.

Rye spikelets grow tight to the stem, about 1/4" apart, making a woven pattern. 2-4 straight awns come out of each spikelet.

Leaves are fairly wide, flat, soft, and blue-green. The blade has tiny "ears" (auricles) that wrap around the stem.
A Rush and a Sedge





Pacific Rush
Juncus effusus ssp. pacificus
  • Perennial Rush to 4 ft.
  • Stem cross section is round, with 14 ridges running along the stem.
  • Inflorescence branched 1-2"
  • No awns
  • CA Bloom Jun - Aug
  • The stem stops at the flower cluster. Above it is a green bract that looks like a continuation of the stem, but has no ridges.
  • CA native



A branched cluster of flowers, about 2" tall, appears to come off the side of the stem. Like all rushes, the flowers are 6-part and tiny.

There is no leaf blade for this plant, just brown leaf sheaths. Inside the sheath is the stem. The non-native ssp. effusus has green leaf sheaths.

Pacific Rush does well on damp, sunny ground, such as at seeps, shores and marshes.
Tall Flatsedge
Cyperus eragrostis


Small spheres of spikelets perch on stiff, leaf-like bracts, giving this plant its classic Umbrella Sedge look.

Spikelets are arranged in a double umbel at the top of the stem.

The inner umbel is made up of many spikelets containing 2-ranked florets.