Monday, 31 January 2011

Festuca rubra - Red Fescue

Red Fescue has rhizomes -
 it is a spreading plant.
Here it is placed on 1 cm  graph paper

Grass of the Month for January 2011

Festuca rubra has needle-like leaves - as narrow as a bristle.

It grows in lawns.

The upper leaves can be wider and ribbed,
You  can flatten out the upper leaves with your finger nail. 

But the basal leaves you just cannot flatten. They are needle-like.

Upper blades of Red Fescue
can be held over the finger
and opened out and flattened
Upper blade
Basal leaf cannot be opened out

I've chosen this grass because nearly everyone in the UK 
should be able to go out and find some outside their house/flat, 

if not in a lawn nearby, then maybe in a city park, or a road verge.
(It grows in North America and Northern Europe too.)

 January is a cold month - but I just opened the door
and crossed the road
and picked some from the verge opposite,
and some from a little further along, from a three year old pile of soil. 

There are only  four relatively common grasses that have needle-like leaves. So they can be distinguished from all the other common grasses which have broader leaves. 


In the first four months of 2011  I shall show how to distinguish the four grasses with needle like leaves.

Red Fescue is the only one that grows in "ordinary" places. The other three only grow where there are very low nutirents, mostly on bogs or heaths where the soil is acid,  (though Sheep's Fescue will grow on chalk and limestone as well.)

  • Mat Grass- (Nardus stricta) grows on peat or acid sandy soils and moors, especially slightly damper soil.
  • Wavy Hair-grass (Deschapsia flexuosa) grows on acid soils - with Mat grass - but also on drier acid soils and under trees on acid soil, and under conifer plantations - the needles make the soil acid.
  • Sheep's Fescue (Festuca ovina) grows on acid soil as the above two species and also on very basic places (i.e. chalk and limestone)
  • That leaves Red-Fescue (Festuca rubra)- which grows in low nutrient soil that is not acid and medium nutrient soil. (If lots of fertilizer is put on a field it will get out-competed by Rye-grass)

There are actually many varieties of Red Fescue, some having been bred for use in turf, but here we are lumping them all as "Red Fescue" .

Tubular sheath
So what if you are on the border between two habitats? How do you to distinguish the four species if they are not in flower? 

Answer: Look at the blade-sheath junction

This picture illustrates three useful features:-
1. The ligule is very short
2. The sheath is tubular and the top of the sheath is like a v-necked jumper (as seen more clearly below right)
3. To check that the sheath is a tube, rather than having two overlapping edges, the sheath has been bent - the sheath crinkles a little - but there is no separating of two sides of the sheath. - Next month we'll look at Festuca ovina which has open sheaths.

top of tubular sheath has
the appearance of
a v-necked jumper

I found the remains of a flowering shoot

Here at the tip you can see a complete spikelet on the right, with florets with awns (bristles) and with two glumes at the base of the spikelet - then on the left is the base of a spikelet with just two glumes left. the florets have gone.

Two glumes are all that
remain of the spikelet

Why not go out and look in a lawn near you, find a needle-like grass and say "Hello - I've found some Red Fescue".

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