This was an online course provided by The Species Recovery Trust, a charity dedicated to protecting endangered species in the UK (The Species Recovery Trust, 2023). It was delivered by Dominic Price. It provided an introduction to identifying British grasses by picking 5 habitats and commonly found grasses in each (including a few sedges and rushes). It consisted of a video presentation, along with questions to test understanding and finally a zoom call for a Q&A session. My notes are below.

The Species Recovery Trust

Around Britain in 25 Grasses

15 January 2024

Habitats and Species

The following habitats and species were discussed:

*Avenella flexuosa previously known as Deschampsia flexuosa.

Improved grassland

Perennial Ryegrass

(Lolium perenne)

Responds to fertiliser, supports the beef and dairy industry. Is a useful indicator species:

Shiny leaves.

Clasping auricles: wraps around the stem.

Stem base is crimson/purple colour - the only species to have this!

Whiplike strands for flowerheads.

Cock's-foot

(Dactylis glomerata)

Indicates nutrient enriched grassland.

Glaucous.

Floppy.

Flattened base to the stem – on young and vegetative (not on flower).

Flowerhead starts together then opens into 3 parts (chunky).

False Oatgrass

(Arrhenatherum elatius)

Usually on abandoned or ex-arable, poorly managed, on railway embankments, road verges, when soil is enriched

Looks a bit like oats – awns.

Orange roots.

Twisty leaves.

Bendy bottom (never comes straight out), swollen nodes (knobbly knees).

Crested Dog's-tail

(Cynosurus cristatus)

dominant on sheep pasture, semi-enriched

Shiny.

Non-clasping auricle.

White bottom.

Stem leaf 45 degrees.

One directional.

Yorkshire Fog

(Holcus lanatus)

Middling as indicator species, it is present in a lot of different habitats, probably due to abandonment.

Velvety texture – doesn’t look hairy with eye, feels it (especially when rubbed on lips).

Pink stripy pyjamas at bottom of stem (at the most in Spring).

Ghostly pale in late summer.

Creeping Bent

(Agrostis stolonifera)

Agrostis is a large group of grasses.

Very fine flowers.

Pointy leaf – spear like, tapers.

May mix up with Poa – although Poa flowers earlier (late Feb, April/May), Agrostis flowers later (July). But Agrostis flowers are very fine (individual blooms). Poa leaf is also boat shaped, rather than pointy. Tram-line sunken groove in middle of leaf (in Poa) – not present in Agrostis.

To identify to species, need to check ligules, e.g. Agrostis capillaris has wide but not tall ligule. Agrostis stolonifera is taller rather than wide. Don’t often come across ‘common bent’ as much as creeping bent.

Calcareous grassland

Sheep's Fescue

(Festuca ovina)

Is an indicator of low nutrient calcareous grassland, almost as if it doesn’t like living with other plants!

Needly/fine leaves.

Sheaf wrapped around like a cloak (it is not a tube!), to help tell apart from red-fescue. Look for the seam.

Black roots (nearly always).

Whiplike flowerheads, quite pointy, 1 direction.

Red fescue (F. rubra): stem leaf looks like a leaf.

Sheep's fescue (F. ovina): stem leaf looks more like a needle

Meadow Oatgrass

(Avenula pratensis)

Has fewer but larger florets than False Oatgrass

Stiff leaves with grey tops – spiky and rigid clumps.

Underside is waxy green. Top is rough and grey.

Also, has double tramlines.

Quaking Grass

(Briza media)

Basal leaves in pairs, coming out at 90 degrees.

Leaves floppy.

Upright Brome

(Bromopsis erecta)

Is a key indicator of calcareous grassland.

Large heads on thin stems, can be quite red.

Red stripy flowerheads.

Camel’s eyelashes. Not very hairy, but notably long hairs. May muddle with downy oat-grass (but that doesn’t have eyelashes).

Glaucous Sedge

(Carex flacca)

Fold into a v and place over your finger to compare species.

Very glaucous on underside (Glaucous sedge is glaucous below).

Black utricles.

Spring Sedge

(Carex caryophylla)

Has a lime green colour (paler than Glaucous sedge).

Male spike is club-shaped.

Acid grassland

Common Bent

(Agrostis capillaris)

Spear like leaves, no groove.

Fine heads (tickle-grass!)

Has a ‘cleric’s collar’ ligule.

Sweet Vernal-grass

(Anthoxanthum odoratum)

Spiky sausages! (clumpy heads).

Hairs on the auricle (whiskered auricle).

Sometimes roots are aromatic.

Pill Sedge

(Carex pilulifera)

Only pale green sedge in this habitat (yellow-green).

Stems smooth until last cm when rough.

Flower stalks arch out on angle.

Heath Grass

(Danthonia decumbens)

Also grows on chalk.

Pale grey and rigid, semi-prostrate leaves and flower stalks.

Leaf collar with ‘nasal hairs’.

Clumpy head with about 4 flowers.

Mat Grass

(Nardus stricta)

Many leaves at 90 degrees.

Needle-like, tough and wiry.

Really rough clump, feels like a doormat.

Thick tussocky base.

Inflorescences like black whips.

Heath

Wavy Hairgrass

(Avenella flexuosa)*

*Previously known as Deschampsia flexuosa.

Very needly, very fine leaves.

Shiny sheen on flowers/glossy.

Forms clumps/tufts.

Wavy heads.

No ligule.

Waxy to the touch.

Dark green.

Green-ribbed Sedge

(Carex binervis)

Deep green, later in the season brown.

Longer flowerheads than Glaucous or Spring Sedge.

Indented leaf: NOT a flat blade.

Green line on flower.

Fine-leaved Sheep's Fescue

(Festuca filiformis)

Same as sheep’s fescue, slightly finer leaves

Is awn-less so not to be confused with F. ovina.

Heath Rush

(Juncus squarrosus)

Can grow in dry places.

Channelled leaves (‘C’ profile).

Tough rosettes – cant pull it out of the ground!

Half of leaves at 90 degrees.

Striking flowers.

Wet grassland

Soft Rush

(Juncus effusus)

Dark, waxy and smooth.

Pith continuous.

Slightly more clumpy (not as clumpy as compact rush though).

Hard Rush

(Juncus inflexus)

Grey, matt and ridged.

Pith interrupted.

Flowers come out in a spray.

Marsh Foxtail

(Alopecurus geniculatus)

Likes somewhere damp.

Glaucous.

Slim head.

Bent on knee.

Tufted Hairgrass

(Deschampsia cespitosa)

Large flower heads.

Lots of dead leaves in winter.

Vicious one-way barbs.

Fine-flowered v. like Agrostis! But flowerhead is much bigger.

Reflection

I found this online training course very good as a starting point to understand the more common species of grass that can be found in different habitats. By breaking it down into habitat types it allows a novice to go to a location and have some idea about what might be found there.

It was interesting to note Dominic's observation that although the taxonomy may change so that Latin names change over time, the English names tend to change less frequently and remain the same e.g. Wavy Hairgrass. This emphasises to me the importance of clarity when discussing species. The Latin names are often used to avoid ambiguity but as there is a chance they may have changed it is important to keep up-to-date (or to include both Latin and English names)!

The course has inspired me to improve my grasses identification skills as this is an incredibly important plant family, with species often used in categorising habitat types. 

References

The Species Recovery Trust (2023) The Species Recovery Trust. Available at: https://www.speciesrecoverytrust.org.uk/ (Accessed: 10 February 2024).