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 (see pics):
Loose spreading panicle; spikelets with 1 - 2(3) un-awned florets
Loose spreading panicle; spikelets with many un-awned florets
Loose spreading panicle; awned spikelets with 1 - 2(3) florets
Loose spreading panicle; awned spikelets with many florets
Digitate (or nearly so) flower spike
Ligule of hairs
Minute plants often <8 cm tall
Mountain plants often reproducing by shoots from flowers
Agrostis . . . . . Bents
These are difficult to distinguish with precision, requiring microscopic examination, 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, usually <15cm but to 30cm
Aira praecox . . . . Early Hair-grass
Common on dry walls, heaths and dunes; usu. <8cm
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
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; hairy lower sheath, lemma with 4 teeth (arrowed)
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
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 and Drymochloa (this is similar but spikelets <15 mm excl. awns); lvs wider (>4mm) than Festuca
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:
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
Several flat-leaved spp. with leaf auricles clasping the stem have been moved to Schedonorus. Another broad-lvd fescue is Drymochloa sylvatica (Wood Fescue), which is similar to Bromopsis but spikelets <15mm (excl. awns) and 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
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; distinguished from Marram by broad bluish lvs
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":
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
Common in shady woods (exc. S&W Ire), also on mountains; characteristic sprays of small oval spikelets with many narrow (2mm) lvs at right-angle to stem (pic. 4), minute ligule
Poa pratensis . . . . Smooth Meadow-grass
Common; creeping, not tufted; smooth lf sheaths,ligule 1-3 mm, panicle branches usu. in groups of 3-5
Similar is P. humilis (spreading Meadow-grass) to c.30 cm with 3-veined equal sized pointed glumes
Poa trivialis . . . . Rough Meadow-grass
Rough upper lf sheath (check by running lips down it); ligule >4 mm; very common in open woods and damp grassland
Many other Poa spp. recognised, e.g. Poa angustifolia with lvs < 2 mm wide
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-arrow), 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 Moor-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.
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; hairy fringe to ligule but hairless leaf sheath (c.f. Panicum
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
Triticum . . . . . Wheat
Triticum aestivum . . . . Wheat
At edges of old cereal fields, roads and farmland
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
