Grasses

Bearing in mind how difficult grasses (members of the POACEAE family - formerly known as GRAMINAE) are for most amateurs to identify, it is advisable if I keep them on a separate page and in ALPHABETICAL ORDER by genus and species.  I have not taken a serious look at grasses since the mid-1980s (when I was team-leader of a survey of riverside vegetation in Wales and then a surveyor for the Wales Field Unit of the old Nature Conservancy Council). At that time grasses required close examination using a 10x or a x20 hands lens, or at times a binocular microscope (and the specimen needed to be fully in flower), combined with consultation of Hubbard's 'Grasses' with its invaluable full page illustrations - my battered and disintegrating copy was discarded last year during my great clear-out. 


THE BEST REFERENCE BOOKS/FIELD-GUIDES?

 Hubbard's 'GRASSES' was my standard reference work in the 1980s but had barely used it for decades when I had a major clear-out in 2014; as my paper-back copy was in terrible condition, I discarded it. When I returned to seriously attempt to identify grasses, I first bought 'Grasses of the British Isles' by Cope & Gray (which was recommended as the up-to-date work)  but to be honest, am not, as yet, comfortable with this.  So have returned to my 'old' favourite - its slightly larger line drawings of the 'habit' of the grass and more illustrations of floral parts suit me better.


'Grasses of the British Isles' by Tom Cope and Alan Gray, which is now 'the' reference work for this family. IF my memory is correct Cope identified the grass specimens collected during my first expedition to the borderlands of Western Tibet, when working at Kew in the early 1980s. 



As with most things, it makes sense to BEGIN with the common and most readily recognised ones.  In my case, I must try and REFRESH my memory, as I am MORE THAN A LITTLE 'RUSTY' with grasses - having not studied them beyond my time in charge of a survey of riverside vegetation in Wales, more than 30 years ago. Familiarising oneself with the characteristics and attributes of the more prominent and commonly encountered ones, allows you to have confidence you are dealing with the correct species and speeds up the invaluable process of learning how to interpret terminology, especially that in keys - which can be both intimidating and difficult to master as a 'beginner'.  Taking a close look at 'Reed' (PHRAGMITES COMMUNIS) is a suitable starting point, as this has large foliage and floral parts, making them the easiest to deal with.

I have also purchased 'The Vegetative Key to the British Flora' (Poland & Clement), which also meant to be good for grasses.

A-Z LISTING OF GRASSES BY GENUS AND SPECIES

ANTHOXANTHUM
ANTHOXANTHUM  ODORATUM

Colourful display of 'Sweet-scented vernal grass' at Iver Heath Fileds, Buckinghamshire

ANTHOXANTHUM  ODORATUM

Panicles compact, oblong; spikelets 7-9mm; glumes hyaline, keeled, pubescent

Known as 'Sweet-scented Vernal Grass' (a much better name, which has fallen foul of 'abbreviation-culture) in Druce's day; he found this grass abundant and widely distributed in pastures, meadows, open woods, heaths in Buckinghamshire a century ago.  He commented that the 'odour' was due to the presence of Coumarin, an odorous substance also present in Woodruff, Melilot plus Monkey and Soldier orchids. We recognise it as the characteristic 'smell' of newly mown hay - one tends to associate 'odour' as something unpleasant.

Ligule up to 4mm, truncate

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ARRHENATHERUM
ARRHENATHERUM  ELATIUS


'Oat Grass' (ARRHENAHERUM  ELATIUS)

Druce found this to be abundant throughout Buckinghamshire a century ago in close to hedges, roadsides, pastures and thickets, preferring shelter; panicles (when fully open) lax, nodding; spikelets slightly compressed of 2 florets

Nodes prominent, glabrous or pubescent

Ligule very short

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BRACHYPODIUM
BRACHYPODIUM  SYLVATICUM

I think this must be 'Slender False Brome' (BRACHYPODIUM  SYLVATICUM) but am not totally convinced at this stage

Drooping foliage

Tufted +/- erect and pubescent perennial 30-90cm


Druce found this grass to be locally common and generally distributed over woodland areas, in woods, hedges and grassy downs; its yellowish-green foliage was a conspicuous feature of Buckinghamshire's spring vegetation in Buckinghamshire a century ago

Inflorescence 6-15cm

Spikelets 12-25mm, nearly straight, of 7-12 florets

Spikelet with awns exceeding lemma

Glumes lanceolate, acuminate, sparsely pilose and ciliate; lemmas linear-lanceolate, acute, sparsely pilose and ciliate; palea oblong, emarginated or round at tip

Upper surface of leaf; leaves flat, broad (up to 13mm), soft, +/- drooping yellow-green (perhaps when young, not in this specimen), +/- scabrid, sparsely pubescent and ciliate

Under surface of leaf

Sheaths pubescent; nowadays very common in woods and hedges in Buckinghamshire - can also be invasive on chalk grassland

Prominent node; ciliate leaf margin

Hairy leaf

Hairy sheath

A broken ligule, described as laciniate c. 2mm - which does not quite match descriptions

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BROMUS
BROMUS HORDEUS

'Lop-grass' or 'Soft Brome Grass' (BROMUS  HORDEUS - previously B. MOLLIS);  a century ago Druce  found this to be abundantly distributed throughout Buckinghamshire in meadows, waysides, cultivated and waste ground and fallow fields

Panicles usually dense, pedicels mostly shorter than spikelets; lemma soft with prominent veins

Ligule short, truncate, hairy

Leaves flat, soft, more or less pubescent; culms erect or decumbent

The following specimens seem to also come within BROMUS HORDEUS but the culms seem so distinctive in character to warrant being described as a variant or is it a different species?

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BROMUS  RAMOSUS

'Wood Brome' (BROMUS  RAMOSUS)

Druce found this handsome species to be locally abundant in woods, copses and hedges, preferring sheltered shady places and damp soils - found in all the woodland tracts of Buckinghamshire a century ago

An erect perennial commonly 100-140cm; panicles compound 15-30cm broad, often dark purplish or glaucous (not in this specimen)



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BROMUS  STERILIS

This 'weed' - 'Barren Brome' (BROMUS  STERILIS) has invaded and taken over most of my front garden since almost all the Himalayan species were 'removed' last summer, to the dismay of my neighbours.  I am rather taken with the display and as the dislike of my collection of Himalayan plants was a factor in my decision to "cull them", the it does amuse me somewhat that what has transpired is viewed as much worse!  The process was aided by the addition of a truck-load of what my son ordered as 'gravel' but turned out to be much larger, ideal to encourage the brome rather than 'Wall Barley', which has only managed a small foothold.  For me to be devoting time to photographing these weeds and sharing the images with the world, rather than pulling them out, no doubt is beyond comprehension.  I do have an excuse, in that I was all set to 'attack' the front garden when my face had a collision with our concrete drive-way, which has prevented any meaningful gardening for some weeks now.  Perhaps the blood I spilt will encourage yet more 'weeds'.....

Druce, a century ago, found this grass very common and generally distributed in Buckinghamshire in waysides, waste and cultivated ground and wall tops; the panicle drooping, simple or slightly branched, the branches normally longer than spikelets

Ligule

Lemmas linear-lanceolate, margins hyaline, awn usually longer

Even for someone like myself, with decades of field experience and an interest in identifying plants dating back more than 40 years, it takes times to become sufficiently familiar to spot all grasses from a distance - especially when they are in early stages of growth (i.e. flowers not fully open). I came across this brome at the edge of a field of broad beans

I think it is going to prove to be BROMUS STERILIS but am not 100% certain

The ligule seems to fit the description for this species

But it is a good idea to express uncertainty if any exists; there is an expectation that 'experts' will be able to name with absolute confidence EVERY single plant they come across but that is NOT how it works.  At my lectures on Himalayan flora I often say that after telling the audience I am not sure as to the species of one or two of the plants I show images of, that they might be disappointed, after all, I am a supposed 'authority' on Himalayan flora.  They should not be, as expressed uncertainty is a sign of COMPETENCE, not incompetence, since plants vary a great deal and NOWHERE in the world has had itself, numerically poor, flora studied as much as in the UK.  It is hardly surprisingly that the flora of the Himalaya, with several times the number of species and occupying a vast area, is imperfectly known -made worse by very little field-work having been undertaken in the Indian Himalaya since partition.

It is my hope that such an admission will help, those struggling to get "on top" of plant identification, particularly for the more difficult families/genera, to know it is not easy even for those with a great deal of experience - though does get easier.

? BROMUS STERILIS

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CYNOSORUS
CYNOSURUS  CRISTATUS

'Crested Dog's-tail' (CYNOSORUS  CRISTATUS) - no mention of the colourful stamens in 'Flora of the British Isles'; panicle erect, dense and spike-like, narrowly-oblong

Druce found this grass common and generally distributed in dry fields, downs and roadsides except on cold, stiff, clay soils in Buckinghamshire a century ago; some spikelets sterile

Ligule blunt

Node

Wiry, erect, tufted; leaves flat, smooth

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DACTYLIS
DACTYLIS  GLOMERATUS

A fine display of Cock's Foot at Iver Heath Fields, Buckinghamshire in June 2015

Prominent stamens putting on a show

The stamens are not described in 'Flora of the British Isles' - presumably because the display is so brief; I certainly caught this grass at its very best

Colourful stamens on display in June

'Cock's foot' (DACTYLIS  GLOMERATA) - this common grass was the first I identified.

Druce recorded this as abundant and generally distributed in Buckinghamshire a century ago in pastures, meadows, roadsides, woods and waste places, preferring shady situations and a rich damp soil; panicles compound, lower branches usually long; spikelets compressed, shortly pedicelled and crowded in dense masses at the ends of branches

Ligules 2-10mm, acute, torn

Prominent nodes; leaves flat, rough +/- keeled

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HOLCUS

HOLCUS  LANATUS

Yorkshire Fog (HOLCUS LANATUS) at Iver heath Fields, Buckinghamshire

Panicles often pink

Panicle 4-10cm, ovate +/- lobed

Spikelets 3-4mm, crowded; awn not exserted (in HOLCUS MOLLIS the awn is exserted, whilst the nodes are bearded)


Young, pale green growth of 'Yorkshire Fog' or 'Creeping Soft Grass' (HOLCUS LANATUS)

This was the second grass I got to identify, after DACTYLIS GLOMERATA; Druce found this in woods, heaths, chiefly on light porous soils, preferring shelter and partial shade; soft and pubescent; panicle  (often pink) compound, rather close; spikelets compressed of 2 florets

Ligule c. 1mm, truncate

Culms and nodes puberulous or glabrescent


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HORDEUM
HOREDEUM  MURINUM

'Wall Barley' (HORDEUM  MURINUM)

Druce found this in waste places, roadsides, wall-sides, especially in or about villages, preferring shelter but also in full exposure to the sun. 

Spike 4-10cm, compressed

Spikelets 8-12mm; awns 2-4 times as long as lemma

Leaf flat, pilose on both sides
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'Meadow Barley' (HORDEUM SECALINUM)

Known as HORDEUM NODOSUM in Druce's day, he found this locally abundant and distinctly pelophilous (thrives in clay soils) in rich alluvial meadows and clayey pastures in Buckinghamshire a century ago; spike2.5-5cm; glumes setaceous, serrate; awn 2-3 times as long as lemma but shorter than in HORDEUM MURINUM (see above)

No information about ligule provided in 'Flora of British Isles'

Leaves narrow (supposedly less than 5mm wide), flat

Nodes glabrous

* a third species of HORDEUM is founded from the UK - H.MARINUM but as this is a very local plant in grassy places near the sea, I have yet to come across it any may never do so unless I specifically go searching for it

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LOLIUM
LOLIUM  PERENNE

'Perennial Rye Grass' (LOLIUM PERENNE); photographed early June 2015

Druce found this abundant and generally distributed in Buckinghamshire a century ago in pastures, roadsides and cultivated ground; it has long been sown for fodder

Note stamens (middle of June 2015)

Inflorescence (8-15cm) is a single spike with the spikelets edgeways on to the axis; this is very variable; spikelets usually with 8-11 florets

Stamens visible

Ligule insignificant only 1mm, truncate

Wiry clumps 25-50cm
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MELICA
MEKICA  UNFILORA

'Wood Melick' (MELICA  UNFILORA)

Panicles 10-20cm, lax, spreading, ovate, compound

Spikelets 4-5mm, erect, oblong

Glumes unequal, purplish-brown, lanceolate

Known as 'Melic Grass' in Druce's day - locally abundant and gregarious in hedgebanks and shady woods on light soils, preferring upland situations in Buckinghamshire a century ago

Quite attractive - cultivated by grass enthusiasts

Leaves flat, with long, scattered hairs above, rough beneath

Sheaths pubescent, with a ligule-like projection at the mouth, opposite the blade


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PHRAGMITES
PHRAGMITES VULGARIS

'Common Reed' (PHRAGMITES VULGARIS)

Leaves flat, wide, smooth, glaucous below, tapering to long slender points; deciduous in winter

Ligule replaced by a ring of hairs; given the size of this stout, erect, rhizomatous reed of 2-3m, it makes an ideal species for beginners to familiarise themselves with parts of grasses - though as it inhabits swamps and shallow water needs to be taken to avoid, at wetter times of the year, getting one's feet winter whilst taking photos

Druce found this locally abundant at sides or rivers, ponds, streams, in marshes and on wet hedgebanks -in some places a handsome and conspicuous river-side feature; an aggressive, gregarious grass

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POA
I think this is POA  TRIVIALIS

'Rough-stalked Meadow Grass' (POA TRIVIALIS) - Druce found this common in all districts of Buckinghamshire a century ago in meadows, pastures, borders of fields, damp places and roadsides

Panicle 5-10cm, lax, broadly ovate to oblong; spikelets 2-4mm

Long, acute ligule up to 8mm



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