Fescues (Festuca)

By Bruce Homer-Smith

 

Fescues are in the Bluegrass Tribe.

 

Fescue Floral characteristics

·        Inflorescences are generally branched but the branches are not always obvious.

·        Sometimes, all the spikelets line up on one side of the branch.  Mostly, they’re two-ranked.

·        Spikelets tend to be narrow and long, with several florets.

·        Florets almost always have awns.  Count the awns to count the florets in the spikelet.

 

Here are some examples:

 

 

 

Obviously branched:

Blue Fescue (Bromus idahoensis)
Photo by Wilde Legard

 

Some spikelets have no branch but others do:

Small Fescue (Festuca microstachys)

Photo by Zoya Akulova-Barlow

 

 

Notice how the stem wobbles at each connection:

California Fescue (Festuca californica)

Photo by Wilde Legard

 

Spikelets line up on one side and are so dense they hide short branches:

Small Flowered Fescue (Festuca minutiflora)

Photo by Steve Matson

 

Young spikelets appear to connect to a wobbling stem...

Italian Ryegrass (Festuca perennis)

Photo by Wilde Legard

 

 

But this same species, when mature, shows branches:

Italian Ryegrass (Festuca perennis)

Photo by Zoya Akulova-Barlow

 

Florets almost always have awns and glumes never do.


Italian Ryegrass (Festuca perennis) – Photo by Steve Matson

 

 

Leaf Characteristics

·        Leaves occur at the base of the plant.

·        Leaf sheaths that clasp the stem stay open.

·        The leaf collar, where the blade meets the sheath, is generally not hairy.

·        Ligules are very tiny (1/20” or less).

·        The leaf blade is flat or inrolled.

 


Reed Fescue (Festuca arundinacea) - Photo by Keir Morse

 

California has 30 species of Festuca, which is Latin for “straw-like weed”.  Many California fescues are problematic weeds, growing quickly in our cool, wet winters.  Others are classic natives, such as California, Red and Western Fescue.

 

An exception to the “has awns” rule, Italian Ryegrass sometimes shows no awns on some florets, although other florets on the same plant can show awns to 1/3”.

 

 

Corrections/Comments: bruce@PlantID.net

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