Grasses, Rushes & Sedges

Grasses, Rushes & Sedges

These four families of plants are often grouped together because of their similarities - all are monocotyledons and have wind-pollinated flowers. Leaves, when present, are long and narrow with parallel veins.  Because they are not pollinated by insects, their flowers lack petals, scent or other features that attract insects; flowers are often greenish or brownish, and botanists use different terms to describe various flower-parts of grasses and sedges.  There is more on this under the family headings.  Detailed examination these flower-parts is often needed to identify a species.

Identification resources

See our Recording Trees, Wildflowers & Grasses page for guidance on how to record.  Grasses, rushes and sedges are not usually included in wildflower field-guides, so you may need to refer to a different book or identification resource.

More on recording in Leicestershire and Rutland and contacts for our County Recorders are on the webpage of our local VC55 branch of the BSBI.

Video: Key Features of Grasses Useful for Identification (Russell Parry, VC55 BSBI County Recorder) https://youtu.be/Xe6ZYYZqTmw

Video: Two Increasingly Common City Grasses (Russell Parry, VC55 BSBI County Recorder) https://youtu.be/sDTjBdE1Sb4

Field guides:

• Price, D.  2015.  A Field Guide to Grasses, Sedges and Rushes (Species Recovery Trust)
• Gardener & Roberts.  2010.  Guide to Common grasses. FSC.  One of the popular and inexpensive FSC fold-out guides, illustrating some of the commoner species. 
• Rose, F. 1989.  Colour Identification Guide to the Grasses, Sedges, Rushes and Ferns of the British Isles and North-Western Europe. (Viking).  A companion to the popular Wildflower Key
• Hubbard, C.E. 1992. Grasses: A Guide to Their Structure, Identification, Uses and Distribution in the British Isles. (Penguin).  
• Cope, T. & Gray, A. 2009. Grasses of the British Isles (BSBI) - available as an e-book as well as a physical book - see BSBI Handbooks
• Jermy, A.C et al. 2007.  Sedges - 3rd edition (BSBI) -  available as an e-book as well as a physical book - see BSBI Handbooks
• McDougall, E. A vegetative key to Grasses (Bristol ERC). Available from the BSBI - see their Grass ID webpages
• Davis, B N K.  2008. A Field Key to Grasses of the East Midlands (Huntingdon Flora & Fauna Society) may be useful if you can find a copy.

Typhaceae - Reedmace family

Juncaceae - Rush family

Rushes (Juncus) are usually aquatic or prefer marshy ground; they sometimes have rounded or flattened leaves, but several species lack stem-leaves. Stems are usually rounded and with central pith-filled cavity.   Many species have short rhizomes and grow in dense tufts.  Flowers are green- or brownish, with 6 tepals, 3 inner and 3 outer; usually 6 stamens; and a single seed capsule.  'Tepal' is the term used when petals and sepals are similar, instead of being differentiated (as is often the case with flowering plants with coloured petals and green sepals).   Identification of most species involves details of the mature tepals and capsule, so it is helpful to take close-up photos of these parts. 

Wood-rushes (Luzula) have similar flowers but flattened, grass-like leaves, with a fringe of long white hairs, and are usually found in drier habitats.

Note that Club-rushes and Spike-rushes are in the Sedge family (Cyperaceae)

Cyperaceae - sedge family

Many species in this family prefer aquatic or damp habitats. 

Most are in the large and difficult genus of Sedges (Carex), with solid stems, usually three-angled (triangular in cross-section), and flattened grass-like leaf blades, usually arranged in threes (unlike grasses, in twos). The leaf often has a sheathing base wrapped around the stem, with a ligule or membraneous flap at the junction of the leaf blade and the leaf-sheath which can help with identification.  Flowers can be greenish, yellow, brown or black, and are borne in spikelets with separate male and female flowers.   Each spike has a bract underneath it, which is often leaf-like.  Stamens and stigmas are usually 3, occasionally 2, and the fruits or utricles often have a projection at the tip, called a beak.   The male and female flowers have a bract-like glume at their base.  Identification of many species is difficult and requires mature specimens and close examination of the male or female glumes and the utricles.

The family also includes the Club-rushes (Scirpus, Schoenoplectus, Bolboschoenus, Isolepis), Cotton-grasses (Eriophorum), Galingales (Cyperus) and Spike-rushes (Eleocharis).