Poaceae . . . . . Grass family

Leaves usually linear, flat, long and thin (though often rolled up); usually clearly separated into a cylindrical lower part (sheath) and a flat upper part by a ligule of membrane or hairs; stems usually hollow; flowers much reduced in units (spikelets) of 1-many florets in terminal inflorescences.

Plant woody or herbaceous:


Choose form of flowering shoot (9 options):


N.B. Woodrushes (Juncaceae) are characterised by flat leaves with hairy edges

Dense, usually cylindrical, spikes


Dense spike but with clearly alternate spikelets


Loose spreading panicle (when young often appearing condensed); spikelets with 2 or more flowers


Loose, spreading panicle with awns

Loose, spreading panicle without awns

Loose spreading panicle; spikelets with single flowers (sometimes 2)


Spike one-sided

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Digitate (or nearly so) flower spike


Ligule of hairs


Minute plants usually <5 cm tall


Mountain plants often reproducing by shoots from flowers



Agrostis . . . . . Bents

These are difficult to distinguish with precision, so only samples of 4 of the c.10 main BI spp shown here

Agrostis canina . . . . Velvet Bent

Common; ligules of main stem lvs < 4mm

Agrostis capillaris . . . . Common Bent (= A. tenuis)

Common throughout BI; Ligules of main stem leaves short (<2mm), awns generally 0

Agrostis curtisii . . . . Bristle Bent (= A. setacea)

Common on dry sandy heaths in SW En; densely tufted with long awns

Agrostis stolonifera . . . . Creeping Bent

Abundant in damp areas throughout BI; long trailing stolons; flowers rarely with awns

Other relatively common bent spp. include A. gigantea (Black Bent), A. vinealis (Brown Bent) and A. scabra (Rough Bent)

Aira . . . . . Hair-grass


Aira caryophyllea . . . . Silver Hair-grass

Frequent across BI on dry walls, heaths or dunes

Aira praecox . . . . Early Hair-grass

Common on dry walls, heaths and dunes

Alopecurus . . . . . Foxtails


Alopecurus aequalis . . . . Orange Foxtail

In En and Wa - similar places to Marsh Foxtail but less common ; lemmas unawned; anthers orange

Alopecurus geniculatus . . . . Marsh Foxtail

Wet grassland or marshes; conspicuous "knees" at lower nodes which can root; yellow to purple anthers

Alopecurus myosuroides . . . . Black-grass or Black Twitch

A bad annual weed of winter cereals, esp. in S & E Br, scattered elsewhere

Alopecurus pratensis . . . . Meadow Foxtail

A common early flowering perennial grass on rich soils; glumes hairy; anthers yellow or purple

Other spp. less common include A. magellanicus and A. bulbosus.
Timothy grasses (Phleum spp.) are similar but spikes are more perfectly cylindrical.

Ammophila . . . . . Marram


Ammophila arenaria . . . . Marram

Common on coastal sand dunes

Anisantha . . . . . Bromes

Choose between the three commoner spp. (in LH 2 pics) and A. madritensis (RH pic -which has a v. dense head in comparison):

Anisantha diandra . . . . Great Brome

Lemmas >20 mm; common exc. W Sc and NW En and W/N Ire

Anisantha madritensis . . . . Compact Brome

Rather local in S and CI and Scilly and SE Ire

Anisantha rigida . . . . Ripgut Brome

Lemmas >20 mm; rather local and scattered in Scilly, CI and E En; Note short stalks to spikelets

Anisantha sterilis . . . . Sterile Brome

Lemmas <20 mm; common exc. in N & W of Sc and Ire

Anthoxanthum . . . . . Sweet Vernal-grass


Anthoxanthum odoratum . . . . Sweet Vernal-grass

Common

Arrhenatherum . . . . False Oat-grass


Arrhenatherum elatius . . . . False Oat- grass

Common

Avena . . . . . Oat-grass


Avena barbata . . . . Slender Oat-grass

Lemmas with apical points <2mm; rare alien in Guernsey; a similar sp. is A. strigosa

Avena fatua . . . . Wild Oat

Note tuft of hairs at base of lemma (see 4th pic)

Avena sativa . . . . Oat


Avenella . . . . . Wavy hair-grass

Was Deschampsia

Avenella flexuosa (was Deschampsia) . . . . Wavy Hair-grass

Acid heaths throughout BI exc. C En and Ire; ligule blunt 0.5-3 mm

Also the rather local in bogs (esp. coastal in N & W) Bog Hair-grass (Aristavena setacea) which has a longer and sharp ligule (2-8 mm)

Avenula . . . . Downy oat grass

(has been Helictotrichon)

Avenula pubescens . . . . Downy Oat-grass

Grassland throughout BI, esp. on chalk/limestone in S En

Brachypodium . . . . . False-brome


Brachypodium pinnatum . . . . Heath False-brome

Awns <5 mm, ligule >1.8 mm, spikelets and leaf sheaths hairy, flat lvs, scattered in grassland En, Wa & Ire; [N.B. B. pinnatum has historically been used for Tor Grass (= B. rupestre)]

Brachypodium rupestre (historically called B. pinnatum!) . . . Tor-grass

V. similar to the above, awns <5 mm, ligule <1.8 mm, but spikelets and leaf sheaths usu. hairless, inrolled lvs c.5mm wide, flower stalks erect; scattered in grassland on chalk and limestone in C, S & E En; definitive separation of the spp. requires a microscope

Brachypodium sylvaticum . . . Slender False-brome

Characteristic pale-green broad soft leaves, awns >7 mm; widespread in shady woodland


Briza . . . . . Quaking-grass


Briza maxima . . . . Large Quaking-grass


Briza media . . . . Lesser Quaking grass


Bromopsis . . . . . Bromes


Bromopsis erecta . . . . Upright Brome

The commonest tall grass of calcareous grassland, esp. in S & E; flowers often purplish

Bromopsis ramosa . . . . Hairy Brome

Very hairy leaves and sheaths, with hairs often downward-pointing; has pointed auricles (fig. 3- after Rose) unlike other most bromes; panicle hanging; lowest node of panicle with 2 long branches; common in shady woodland

Bromopsis benekenii . . . . Lesser Hairy-brome

Similar to B. ramosa (may be subsp.) but slightly smaller; panicle swept to one side; lowest node of panicle with >2 branches some with few spikelets, and hairless upper lf sheath

See also Bromus, Anisantha, Ceratochloa

Bromus . . . . . Brome Grass


Bromus racemosus . . . . Smooth Brome

Has "more leathery" Lemmas than B. hordeaceus; locally frequent in C & S Br; also incorporates Meadow Brome (B. commutatus)

Bromus hordeaceus . . . . Soft Brome

V. variable; 4 subspp. recognised; the tiny plants of dunes and cliff-tops are likely to be subsp. thominii if flowers hairless, or subsp. ferronii if glumes hairy (see below)

These subspp. include:

Bromus hordeaceus subsp. feronii . . . . Soft Brome

Florets (glumes and lemmas) are hairy

Bromus hordeaceus subsp. thominii . . . . Soft Brome

See also Bromopsis, Anisantha, Ceratochloa

Calamagrostis . . . . . Small-reed


Calamagrostis canescens . . . . Purple Small-reed

Less common than the below but in largely similar areas, esp. C E En; ligules 2-4 mm; upper side of lf hairy

Calamagrostis epigejos . . . . Wood Small-reed

In damp open woodland and heaths across BI, mostly towards S & E; jagged ligules 4-10 mm

There are also three other rare spp.

Catabrosa . . . . . Whorl-grass


Catabrosa aquatica . . . . Whorl-grass

Throughout the BI in water

Catapodium . . . . . Fern-grass


Catapodium marinum . . . . Sea Fern-grass

All round the coasts of BI

Catapodium rigidum . . . . Fern-grass

Throughout En, Wa and Ire, but uncommon in Sc exc. on coast S of Edinburgh

Ceratochloa . . . . . Bromes


Ceratochloa carthartica . . . . Rescue Brome

Strongly flattened spikelets with sharp edges; CI, Scilly and SE En - scattered elsewhere in En

The rather similar C. carinata (Californian Brome) has smaller spikelets (<30mm) and awns to 10mm; centres of distribution around London and Liverpool, scattered elsewhere in Br

Cortaderia . . . . . Pampas-grass


Cortaderia selloana . . . . Pampas-grass


Corynephorus . . . . . Grey Hair-grass


Corynephorus canescens . . . . Grey Hair-grass

Very similar to Koeleria macrantha (see L of Fig 3) but much more silvery; very local in Jersey, East Anglia, Moray firth and a few other locations

Cynodon . . . . Bermuda-grass


Cynodon dactylon . . . . Bermuda-grass

Characteristic digitate flower heads; Common in CI and Scilly; also occurs in S En and S Wa

Compare also: Digitaria

Cynosurus . . . . . Dog's-tail


Cynosurus cristatus . . . . Crested Dog's-tail

Common

Cynosurus echinatus . . . . Rough Dog's-tail

Local in CI, Scilly and S En

Dactylis . . . . . Cock's-foot

Dactylis glomerata . . . . Cock's-foot


Danthonia . . . . . Heath-grass


Danthonia decumbens . . . . Heath-grass


Deschampsia . . . . . Tufted Hair-grass


Deschampsia caespitosa . . . . Tufted Hair-grass


See also Avenella (was D. flexuosa)

Digitaria . . . . . Hairy Finger-grass


Digitaria sanguinalis . . . . Hairy Finger-grass

Locally common in CI and scattered in S

See also: Cynodon

Echinochloa . . . . . Cockspur


Echinochloa crus-galli . . . . Cockspur


Elymus . . . . . Couch


Elymus athericus (was Elytrigia atherica). . . . Sea Couch

Common on coasts in S, rare in Sc; Tall - up to 120 cm; spikelets overlapping; leaf veins without hairs - often hard to distinguish from glaucous (maritime) variants of E. repens

Elymus caninus . . . . Bearded Couch

Scattered in shady woodland and riversides throughout BI, esp. in En and Wa

Elymus junceiformis (was Elytrigia juncea) . . . Sand Couch

Common all around BI coasts; Shorter (to 60 cm) and more spreading than E. atherica, spikelets hardly overlapping; leaf veins minutely hairy

Elymus repens (was Elytrigia repens) . . . . Common Couch

Abundant on cultivated or waste ground, also near the sea, throughout BI

Elytrigia . . . . . Couch

See Elymus

Festuca . . . . . Fescues


Several flat-leaved spp. with leaf auricles clasping the stem have been moved to Schedonorus. Another broad-lvd fescue is Drymochloa altissima (Wood Fescue), but this is restricted to wet ravines in N & W

Note that many Festuca spp. have been identified, but they are very hard to separate, requiring detailed examination, so here just the main groupings (F. ovina and F. rubra are described with a few other examples shown. Distinguishing features include - whether tillers come out at base or within leaf sheaths (LH pic) and whether leaf sheaths fused (lvs easily pulled away from the stem or not (RH pic)):


Festuca ovina . . . . Sheep's-fescue

A very common grass with tillers emerging from within the lower leaf sheaths; leaf sheaths not fused (lvs easily pulled away from the stem - see RHS of Fig. 4)

This agg. includes rare spp. such as:

Festuca huonii . . . . Huon's Fescue

Panicles only just emergent at flowering; rare on cliffs in CI

Festuca amoricana . . . . Breton Fescue

Jersey, rare

Festuca rubra agg. . . . . Red Fescue

A very common grass like F. ovina but lvs of flowering stems sometimes flat (not thread-like) and tiller leaf sheaths fused to mouth (not split below the ligule - see fig on R below); tillers emerge at right angles from the base (see Fig on L).
Plants with lvs >4 mm wide likely to be F. altissima

Festuca heterophylla . . . . Various-leaved Fescue

Basal lvs thread-like, upper flat

Festuca vivipara . . . . Viviparous Fescue

On hills/mountains esp. in W & N

Glyceria . . . . . Sweet-grass


Glyceria fluitans . . . . Floating Sweet-grass

Wet places, often in water; note that there are usually only 1 or 2 branches at each node of the flower spike

Glyceria declinata . . . . Small Sweet-grass

The lemmas have a three-pointed tip

Glyceria maxima . . . . Sweet Reed-grass

Tall (to 2m+), lvs 2cm wide with toothed edges; Frequent in or close to rivers, ponds, etc, esp. in En, C and E Sc; less common elsewhere

Helictochloa . . . . . Meadow Oat-grass

Was Avenula or Helictotrichon

Helictochloa pratensis . . . . Meadow Oat-grass

Similar places to Avenula but commoner on mountains and hardly in Ire or SW Br

Hierochloe . . . . . Holy-grass


Hierochloe odorata . . . . Holy-grass

Local in marshy areas in S & C Sc

Holcus . . . . . Soft-grasses


Holcus lanatus . . . . Yorkshire-fog

Common on rough grassland throughout the BI

Holcus mollis . . . . Creeping Soft-grass

Conspicuous hairy nodes; common in shady grassland (e.g. in woods) exc. w Ire

Hordeum . . . . . Barley


Hordeum murinum . . . . Wall Barley

Lvs with pointed auricles

Other barleys include H. marinum (Sea Barley), in which any auricles are not pointed, locally common by the sea in S Br. Also escaped cultivated 6-row Barley (H. vulgare) and cultivated 2-row Barley (H. distichon).
2-row Barley
6-row Barley

Koeleria . . . . . Crested Hair-grass


Koeleria macrantha . . . . Crested Hair-grass

Throughout BI especially near the sea on calcareous soils or dunes

Also the rare Somerset Hair-grass (Koeleria vallesiana) which is restricted to limestone grassland in N Somerset; distinguished by swollen stem base and residual mat of dead leaf sheaths

Lagurus . . . . . Hare's-tail


Lagurus ovatus . . . . Hare's-tail

Abundant near sea in CI, an uncommon casual elsewhere esp. Devon and Sussex

Leymus . . . . . Lyme-grass


Leymus arenarius . . . . Lyme-grass

Frequent on mobile dunes around BI coasts but not common in the S En, S & W Ire or CI

Lolium . . . . . Rye-grass


Lolium multiflorum . . . . Italian Rye-grass

Widely planted in grassland, less common in N & W of Br &Ire

Lolium perenne . . . . Perennial Rye-grass

Common grass, widely planted component of grass mixes

Melica . . . . . Melick


Melica nutans . . . . Mountain Melick

Scattered in woods on limestone, mostly in Sc and N En, but extending S to N Wa

Melica uniflora . . . . Wood Melick

Locally commmon in woods exc. CI, N Sc and much of S & W Ire

Mibora . . . . . Early Sand-grass


Mibora minima . . . . Early Sand-grass

A tiny, v. early-flowering local plant of sandy soils by sea, esp. in CI, Anglesea and Lancashire

Milium . . . . . Wood Millet


Milium effusum . . . . Wood Millet

In shady woodland throughout BI, more common in S & C Br

Miscanthus . . . . . Silver-grass


Miscanthus sinensis . . . . Chinese Silver-grass

An increasingly planted oriental grass that has naturalised especially in the London area

Molinia . . . . . Purple Moor-grass


Molinia caerulea . . . . Purple Moor-grass

Tufted, on wet acid moorland or bogs, widespread, hairy ligules and tough stems

Nardus . . . . . Mat-grass


Nardus stricta . . . . Mat-grass

On acid heaths, moors and mountains - often dominant

Panicum . . . . . Millets


Panicum capillare . . . . Witch-grass

An unusual birdseed casual - mostly in the S and E of En; spikelets 1.5-3 mm

Panicum miliaceum . . . . Common Millet

More frequent casual than P. capillare in En and Wa, and SW Ire; Spikelets c. 5 mm; Note the hairy sheath (cf. Sorghum)

Parapholis . . . . . Hard-grass


Parapholis strigosa . . . . Hard-grass

Frequent on coasts N to C Sc; flowering spikes nearly straight

Parapholis incurva . . . . Curved Hard-grass

Unlike the above, the flower spike usually part enclosed by leaf sheath; usually <10cm; Local on coasts Ci and S Br

Pennisetum . . . . . Feathertop grass


Pennisetum villosum . . . . Feathertop grass

Introduced ornamental grass sometimes establishing itself in S

Phalaris . . . . . Canary-grasses


Phalaris arundinacea . . . . Reed Canary-grass

Common in damp places across Br; fl heads condensed when fruiting

Do not confuse with other "reeds":

Phalaris canariensis . . . . Canary-grass

Annual, cf. P. aquatica below


Phleum . . . . . Cat's-tails


Phleum alpinum . . . . Alpine Cat's tail


Phleum arenarium . . . . Sand Cat's-tail


Phleum pratense . . . . . Timothy

P. bertolonii Smaller Cat's-tail is very similar - but smaller (shown on RHS of 3rd picture)

Phleum bertolonii . . . . Smaller Cat's-tail

Smaller Cat's-tail is very similar to P. pratense - but smaller with heads only a few cm long

Phragmites . . . . . Common Reed


Phragmites australis . . . . Common Reed

Common in wet places; note the hairy ligule

Do not confuse with other "reeds":

Poa . . . . . Meadow-grasses

Only a few of the many spp. in the BI are illustrated here; most are difficult to separate - some guidance given in table
Woodland plants
Grassland
Mountain plants
Large plants

Poa annua . . . . Annual Meadow-grass

Very common; 'tooth-marked' (transversely wrinkled -Fig2) lvs. [The similar Early Meadow-grass (P. infirma) occurs mostly in S BI and has squarish anthers <0.5 mm vs. long anthers]

Poa alpina . . . Alpine Meadow-grass

Leaves abruptly narrowed at tip; often viviparous; local on mountains

Poa bulbosa . . . Bulbous Meadow-grass

Mostly on sandy soil nr the sea in S Br; characteristic bulbous base to stems; narrow lvs <2mm; is sometimes viviparous

Poa chaixii . . . Broad-leaved Meadow-grass

A large plant (to 1.5 m) with lvs >1 cm wide, scattered in woods etc. in Br esp. in Sc, lowest panicle node with 4-7 branches

Poa compressa . . . . Flattened Meadow-grass

Clearly flattened stem; bent at nodes; scattered on waysides throughout BI

Poa glauca . . . . Glaucus Meadow-grass

Glaucus; top lf <1/2 way up stem; local on mountains in Sc

Poa nemoralis . . . . Wood Meadow-grass

Scattered in woods, shady places and mountains; minute ligule, many narrow (2mm) lvs at right-angle to stem

Poa pratensis . . . . Smooth Meadow-grass

Common; creeping, not tufted; smooth lf sheaths,ligule 1-3 mm, panicle branches usu. in groups of 3-5

Poa trivialis . . . . Rough Meadow-grass

Rough upper lf sheath (check by running lips down it); very common in open woods and damp grassland

Many other Poa spp. recognised

Polypogon . . . . . Water Bent


Polypogon viridis . . . . Water Bent

On roadsides and waste ground, esp. in CI and S to C Br and SE Ire but spreading rapidly; local in Scotland

Pseudosasa . . . . . Arrow Bamboo


Pseudosasa japonica . . . . Arrow Bamboo


Many other Bamboos have been introduced and sometimes escape from cultivation - e.g. in old parks, etc., these include spp. of Sinarundinaria (Fountain Bamboos), Pleioblastis, Sasa, Sasaella, and Chimonobambusa.

Puccinellia . . . . . Saltmarsh-grass


Puccinellia distans . . . . Reflexed Saltmarsh- grass

A tufted plant with lemmas <2.8mm, anthers >0.75mm; more common on saltmarshes in E Br

Note there are two subspp. and several hybrids as well as two other tufted spp in BI

Puccinellia maritima . . . . Saltmarsh-grass

Spreading with many tillers and rooting stolons; lemmas >2.8mm; common round coasts in saltmarshes

Schedonorus . . . . . Fescues


Schedonorus was until recently included among Festuca. The 3 common spp. are compared below:

Schedonorus arundinaceus . . . . Tall Fescue

A tall, tufted grass to c.1.5 m, with pointed & often hairy auricles clasping stem (see pic 1), and white leaf sheaths at base of stem; Common in grassy places and damp shady areas


Schedonorus giganteus . . . Giant Fescue

(=Festuca giganteus)Wavy awns and broad lvs; common shady places exc. N Sc & CI

Schedonorus pratensis . . . . Meadow Fescue

Similar to S. arundinaceus, but smaller (to c.1 m), lvs c. 4mm wide with only fine teeth; lower sheaths brown (not white); hairless auricles; Note that only one long branch plus 1 or 2) sessile spikelets at each node; Common in damp meadows, waysides, etc.

Sesleria . . . . . Blue Moor-grass


Sesleria caerulia . . . . Blue Moo-grass

Locally common on limestone in W Ire and N En

Setaria . . . . . Bristle-grasses


Several spp. are found scattered as introduced casuals, mostly from the Midlands S-wards: e.g.

Setaria pumila . . . . Yellow Bristle-grass (or Yellow Foxtail-grass)



Setaria verticillata . . . . Rough Bristle-grass

A scattered casual mainly S of Manchester; the head feels rough owing to backward bristles

Sorghum . . . . . Sorghum


Sorghum bicolor . . . . Sorghum

A birdseed casual, esp. in S

Spartina . . . . . Cord-grass


Spartina anglica . . . . Common Cord-grass

Saltmarshes around the coast, esp. S from S Sc and S Ire

A number of other Spartina spp. occur with more local distribution

Sporobolus . . . . . Dropseed


Sporobolus indicus . . . . Dropseed

An uncommon birdseed casual

Trisetum . . . . . Oat-grass


Trisetum flavescens . . . . Yellow Oat-grass

Grassland, esp. calcareous - common S of C Sc; has characteristic kinked awn

Vulpia . . . . . Fescues


Vulpia bromoides . . . . Squirrel-tail Fescue

Throughout BI, but less frequent in N Sc; lower glume >1/2 length of upper (see 4th pic); upper leaf sheath ending well below flowers

Vulpia fasciculata . . . . Dune Fescue

Locally common on sand dunes in Br and Ire, commonest in W; inflated upper lf sheath, lower glume v. short or 0, upper relatively v. long and awned (see 4th image)

Vulpia myuros . . . . Rat's-tail Fescue

Most common in S half of BI, but occurs further N; lower glume c.1/4 length of upper (see 4th image); upper leaf sheath reaching the flowers


Zea . . . . . Maize


Zea mais . . . . Maize

An agricultural crop rarely self-seeding