Grasses

Carex pendula (up to 200 cm) Pendulous sedge Tall sedge that forms clumps. Three-sided stem. Catkins droop distinctively. Yellowish-green leaves are glaucous below (2 cm wide). Found in damp woodland and stream banksides, particularly on clay soil. Image taken at Powerstock Common, near Dorchester, Dorset .

Ammophila arenaria (up to 120 cm) Marram Tall grass of sand dunes. Roots bind the sand together. Long straw-coloured spike present from June to August. Greyish-green leaves with points. Widespread and common on the coast. Image taken at Prestatyn, Denbighshire .

Carex riparia (up to 130 cm) Greater pond sedge Tall grass that forms patches in wet meadows, swamps and near freshwater. Three-sided stems. Mature catkins are dark brown and droop. Broad leaves (6-15 mm wide). Image taken at River Avon, Salisbury, Wiltshire .

Deschampsia cespositosa (up to 200 cm) Tufted hair grass Tall, tufted grass with distinctive silvery-purple spikelets. Spikelets are present from June to August. Dark green leaves have rough edges. Found in damp grassland, woodland, marshes and mountains. Widespread and common. Image taken at River Avon, Salisbury, Wiltshire .

Typha latifolia (up to 300 cm) Bulrush Tall leaves and stems. Small flowers packed into a disctinctive sausage-shaped brown spike (18-30 cm). The male flowers are fluffy golden-brown and located above the numerous chocolate females. Flowers from June to August. Greyish leaves (8-24 mm wide). Found in and near freshwater. Image taken at Bentley Wood, near Winterslow, Wiltshire .

Sparganium erectum (up to 150 cm) Branched bur-reed Largest bur-reed. Flowers in a branched spike. Broad lanceolate leaves (10-15 mm wide) with long translucent veins that lack a black border. Found near freshwater. Widespread and common. Image taken at Leighton Moss RSPB reserve, Silverdale, Lancashire .

Eriophorum angustifolium (up to 75 cm) Common cotton-grass Commonest cotton-grass. Flowers with bright yellow anthers present from April to May. White fluffy fruiting bodies present from May to July. Three-sided smooth stem at the top. Leaves are 3-5 mm in width with a long tip. Found on wet heaths and bogs, particularly on acidic soils. Image taken at Meathop Moss, near Silverdale, Lake District, Cumbria .

Grasses have long, narrow leaves with parallel veins. The leaves form a sheatharound the stem. The stems are hollow and rounded. The flowers are grouped into spikelets, present as singlets or pairs. The spikelets are arranged in a number of ways - stalkless, in spikes or with long stalks in branched flowerheads.

The bulrushes and reedmaces have unisexual flowers packed densely into separate velvet spikes on the same stem. The male cluster lies above the female flowers.

Sedges are similar to grasses but possess solid, three-sided stems. The leaves form a cylinder around the stem. The flowers are grouped into spikes. The true sedges (Carex spp) possess flower spikes containing one sex only.