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) |
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 Copyright: https://PlantID.net/Contributors.aspx |