Meadow-grasses & Allies
What are they?
The true meadow-grasses are in the genus Poa and form a rather difficult group of species as some can be rather similar and there has been changes of opinion on the species boundaries in this group over the years. This page also includes a small number of other grasses that could be confused with meadow-grasses, especially during the period when the flowers are fully opened and the structure of the flowering spike can look rather similar to true meadow-grasses.
Where are they found?
Some of the meadow-grasses are amongst the commonest and most widespread of our grasses in a wide range of grassy habitats, especially on roadsides, rough ground and urban environments. Other species are uncommon and rather specialist in their habitat requirements, so habitat can be an important part of identification.
Identification
Click here for help with some of the terminology used on the grass pages. Meadow-grasses may be annual or perennial and typically have rather open flower panicles with the lower branches longer than the uppers, forming a tapered flower spike. The florets are not solitary but clustered, two or more together, into small, tight spikelets. The lemmas are unawned and strongly overlapping and often keeled. This can be a difficult group to identify to species and measurement of very small parts is sometimes required. However, a certain amount of help can come from habitat and the overall appearance (including size) of the plant.
Smooth Meadow-grass Poa pratensis
A native perennial found in many types of grassy places such as lawns, meadows and roadsides, as well as cracks in walls and pavements etc., but typically avoiding wetter places. Flowers May to July. Plants 10-80cm in height according to habitat (shorter in dry, open places, taller when among other plants or in shade) and spreading to form extensive patches. Leaf blades and sheaths hairless, pointed at the tip or slightly rounded and hooded, 2-5mm wide. Leaf ligule membranous, short. Flower spike open and spreading at anthesis and remaining open at fruiting, with 3-5 branches at the lowest node. Spikelets densely packed with 2-5 florets. Note that this is the commonest of a cluster of rather similar species and subspecies found in East Anglia.
 |
 |
 |
 |
| |
|
|
|
 |
|
 |
 |
| |
|
|
|
Rough Meadow-grass Poa trivialis
A native perennial found in many types of grassy places such as lawns, meadows and roadsides, but especially favouring shady places and the meadow-grass most commonly occurring in woods and wetter places. Flowers June to July. Plants 20-100cm in height and spreading to form extensive patches by means of many, non-flowering shoots (tillers). Leaf blades 1.5-6mm wide, hairless, pointed at the tip. Leaf sheaths keeled, slightly rough to the touch. Leaf ligule membranous, long. Flower spike open and spreading at anthesis and remaining open at fruiting, with 3-7 branches at the lowest node. Spikelets densely packed with 2-4 florets. Typically the largest of the three common meadow-grasses.
 |
 |
|
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Narrow-leaved Meadow-grass Poa angustifolia
A native perennial found in grassy places on dry soils such as heaths, commons and roadsides. Flowers April to July. Plants 20-70cm in height according to habitat. Leaf blades 1.5-2mm wide, rather variable but generally noticeably fine and narrow. Leaf ligule membranous, short. Flower spike open and spreading at anthesis and remaining open at fruiting, branches fine, mostly in clusters of 3-5. Spikelets relatively small, 2.5-5mm, densely packed with 2-5 florets. Told from similar meadow-grasses by the long, narrow and rather stiff leaves that can resemble those of Red fescue. One of the species in the Smooth Meadow-grass complex.
| |
 |
 |
| |
|
|
 |
 |
 |
| |
|
|
Spreading Meadow-grass Poa humilis
A native perennial found in a wide range of grassy places, both damp and dry. Flowers June to July. Plants 3.5-25cm in height according to habitat. Leaf blades 1.5-4mm wide, rather variable but often slightly bluish-tinted and relatively short. Leaf ligule membranous, short, often accompanied by stiff hairs around the base of the leaf blade. Flower spike open and spreading at anthesis and remaining open at fruiting, branches mostly in clusters of 2-3 (including at the lowest node). Spikelets 4-7mm, densely packed with 2-4 florets. A rather small meadow-grass with often solitary and widely spaced flower spikes. One of the species in the Smooth Meadow-grass complex.
 |
 |
 |
 |
| |
|
|
|
 |
 |
||
| |
|
Annual Meadow-grass Poa annua
A native annual or short-lived perennial found in all types of open ground, bare patches in lawns, gravel drives, cracks in walls and pavements etc. Flowers more or less throughout the year, but especially from late November to June. Leaves hairless, pointed at the tip or slightly rounded and hooded, 1-5mm wide. Flower spike open and spreading at anthesis and remaining open at fruiting. Spikelets densely packed with 3-10 florets. Anthers prominent at anthesis, 0.6-0.8mm and 2-3x as long as wide. Plants in dry places can be very small and compact, but more open and spreading in shady or wetter places.
 |
|
 |
 |
| |
|
|
|
 |
 |
 |
|
| |
|
|
Early Meadow-grass Poa infirma
A native annual, once confined in the UK to the south-west peninsula of England but it has spread along the South Coast and north into East Anglia where it is now frequent near the coast in open, usually sandy habitats and some urban environments and occasionally appears at inland sites. Flowers March to May. Leaves hairless, pointed at the tip or slightly rounded, 1-4mm wide. Flower spike rather compact at anthesis but open at fruiting. Spikelets densely packed with 2-4 florets. Anthers prominent at anthesis, but tiny, 0.2-0.5mm and 1-1.5x as long as wide. Very like a small Annual Meadow-grass but tending to be more yellowish-green in colour and flowering for a relatively short period in spring.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
|
| |
|
|
Bulbous Meadow-grass Poa bulbosa
A native perennial that can be common but easily overlooked on coastal sand dunes and a few sandy sites inland. Flowers March to May. Plants 5-30cm in height according to habitat (typically very small in coastal sands). Leaves hairless, abruptly pointed at the tip, 0.5-2mm wide, grey-green over winter but soon becoming purplish then withering by late spring. Leaf ligule membranous, up to 4mm long. Flower spike open and spreading at anthesis and remaining open at fruiting. Spikelets with 1-5 florets. A distinctive plant, but tiny and easily overlooked. Plants soon wither by late spring and with the drying out of the sand over summer, the bulbous-based plantlets can get dislodged and are dispersed by the wind. With autumn rains, the plantlets form new roots and leaves and are wintergreen.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
|
| |
|
|
Flattened Meadow-grass Poa compressa
A native perennial which favours dry ground and takes readily to growing from cracks in walls and pavements etc. Flowers June to August. Plants 10-60cm in height with stems distinctly flattened in one plain. Leaf blades 1-4mm wide, bluish- or greyish-green with keeled sheaths. Leaf ligule membranous, rounded, 0.5-3mm long. Flower spike rather variable but typically with rather short lower branches, giving it a rather cylindrical outline. Spikelets 3-8mm, with 3-10 florets. The stiff, flattened stems and rather narrow flower spikes are rather distinctive.
 |
 |
 |
 |
| |
|
|
|
 |
 |
||
| |
|
Wood Meadow-grass Poa nemoralis
A native perennial, thinly scattered in woodland and shady places. Flowers June to July. Plants 50-80cm in height, forming a loose tussock. Leaves 1-3mm wide, flat, green, soft and rather delicate. Leaf sheaths rounded, smooth. Ligule membranous, very short, 0.2-0.5mm in length. Flower spikes very delicate, narrow and upright but opening out by anthesis and soon becoming gracefully arched over, 3-20cm in length with many spikelets. Spikelets 3-6mm, 1-5 flowered, clustered towards the ends of thin and sinuous branchlets. Glumes equal or nearly so in length, fine pointed. Lemmas 2.6-3.6mm, keeled and pointed with membranous edges and tips. A delicate and graceful grass.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Water Bent Polypogon viridis
An introduced annual or short-lived perennial, probably being spread as a weed of the nursery industry and once a rare casual, but now increasingly common in urban situations, growing from cracks in paving and walls and occasionally in flowerbeds and gravel paths. Flowers June to August. Plants 10-60cm in height with perennial plants forming creeping stolons and tufted patches. Leaf blades 2-10mm wide, hairless but a little rough to the touch, pointed at the tip. Leaf sheaths rounded, smooth. Leaf ligule membranous, rounded, 1.5-6mm long. Flower spike narrow when young, open and spreading at anthesis and remaining open at fruiting. Spikelets tiny, 1.7-2.2mm, very numerous, not clustered towards the tips of the branchlets with a single floret in each spikelet. Lemmas not awned. Rather distinctive once known, with relatively broad leaves held out, flag-like, from the flower spikes and with a dense mass of florets, but easily mistaken for a small meadow-grass at first.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Whorl-grass Catabrosa aquatica
Native. A patch-forming perennial, growing on damp mud in water meadows and alongside rivers and ponds, often forming floating mats. Generally uncommon except along section of the Bure and Wensum in Norfolk and parts of coastal Suffolk. Flowers May to July. Plants 5-75cm in height with stems often bending upwards from a prostrate base. Leaf blades 2-10mm wide, hairless and smooth, blunt at the tip. Leaf sheaths compressed, smooth. Leaf ligule membranous, 2-8mm long, whitish. Flower spike open and spreading at anthesis with the branches typically angled slightly downward. Spikelets 3-5mm, loosely 1-3 flowered. Lemmas not awned. The flowering spike is rather like the larger meadow-grasses in general appearance, but the florets are loosely carried in the spikelets (not densely-packed) and the habitat is unlike that of the meadow-grasses.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Yorkshire-fog Holcus lanatus
A native perennial, common to abundant in many kinds of grassy places, especially on land that has been improved or disturbed in the past. Flowers May to September. Plants 20-100cm in height, variously as spaced stems or densely tussock-forming according to land use and management. Leaf blades 3-10mm wide, softly hairy or downy, flat and pointed. Leaf sheaths rounded, hairy. Ligule membranous, short to medium. Flower spike very narrow when young and typically pinkish-purple in colour, spreading at anthesis and remaining open with age. Spikelets 4-6mm with usually 2 florets. Lemmas keeled, the lower unawned, uppers shortly awned, making a good distinction from the true meadow-grasses. Can be mistaken for a meadow-grass when the flowering spike is fully open, but the whole plant is very much downier and the narrow flower spike before the flowers open is very different to the meadow-grasses. Compare also with oat-grasses.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Creeping Soft-grass Holcus mollis
A native perennial, common on a variety of soils but most often found on dry soils in shady places and often forming creeping patches in dry birch wood and under gorse and bracken, where other grasses are shaded out. Flowers June to August. Plants 20-50cm in height, often forming leafy colonies with few or no flowering spikes. Leaf blades 3-12mm wide, softly hairy or hairless, flat and pointed. Leaf sheaths rounded, hairy. Ligule membranous, 1-5mm long. Flower spike very narrow when young, spreading at anthesis and remaining open with age. Spikelets 4-7mm with usually 2 florets. Lemmas keeled, the lower unawned, uppers with a slightly bent awn, 3.5-5mm long and clearly protruding beyond the glumes. Stem nodes downy but not conspicuously so.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Rice Cut-grass Leersia oryzoides
Considered a rare native in southern England, but recorded only once as an introduction in our region, near Cambridge. Flowers August to October. Plants 30-120cm in height, the stems hairy at the nodes, otherwise smooth or with scattered, backward-pointing bristles. Leaf blades 5-10mm wide, flat and pointed, rough and with stiff bristles along the margin. Leaf sheaths rounded, finely ribbed, the uppers with scattered, backward-pointing bristles. Ligule membranous, 0.5-1.5mm long. Flower spike with spikelets spread along the side branches rather than clustered at the tips. Spikelets 4-5mm, each with a single floret. Glumes greatly reduced to a tiny rim at the base of the spikelet. Lemmas strongly keeled, with stiff bristles along the keel. The stiff, bristle-like hairs on the plant can cut if handled, giving the plant its English name.
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
|
| |
|
|