Grasses, sedges and rushes

Grasses (flowering plants in the Poaceae or Gramineae family) are the fifth largest plant family, with around 780 genera and about 12,000 species worldwide, including a wide range of wild, semi-wild and cultivated forms.

“They are the most economically important plant family, providing staple foods from domesticated cereal crops such as maizewheatricebarley, and millet as well as feed for meat-producing animals. They provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other grains 6%. Some members of the Poaceae are used as building materials (bamboothatch, and straw); others can provide a source of biofuel, primarily via the conversion of maize to ethanol.” [Poaceae: Wikipedia.]

Sedges (Cyperaceae) and rushes (Juncaceae) are related to the grasses, being members of the order Poales, all of which are monocotyledonous flowering plants. Sedges and rushes are found in a wide and diverse range of habitats, but many species are associated with poorer, less fertile soils and wetlands. 

The sedge family includes about 90 genera with about 5,500 known species, of which the largest genus, Carex or ‘true sedges’ contains about 2,000 species worldwide. Almost all sedges are distinguished from grasses and rushes by having triangular cross-sectioned stems (grasses and rushes are round or tubular in cross-section), and leaves that are spirally arranged in  ranks (grasses have alternate leaves in 2 ranks).

The rush family consists of 8 genera and about 484 known species worldwide. Most rushes have leaves that are well-developed in a basal aggregation on an erect stem. They are alternate and have three rows of leaves up the stem, each row of leaves arising one-third of the way around the stem from the previous leaf. 

About grasses, sedges and rushes

Grasslands first appeared in what is now the South American landmass during the Oligocene epoch (40 million to 23 million years before the present). Although grasses had been present in South America, Africa and India since about 70 million years ago, they had been relatively minor and unimportant plants within tropical and jungle, tree-dominated landscapes. As the world’s climate cycle cooled and land masses drifted towards their present positions during the Oligocene, grasses, which were already well-adapted to the changing climate and exceptional dispersers, proliferated and spread. During the remainder of the Cenozoic era (the last 66 million years of Earth’s history) grasslands have become one of the dominant landscapes of the planet (estimated to constitute 45% of the Earth’s land area).

“Their characteristics make them exceptional dispersers. Their seeds are small and easily spread by wind and by hitching a ride on or within animals. They grow to reproductive age quickly, the seeds are starchy, holding plenty of energy for the developing embryo, and they are able to survive burning, freezing and near-continuous grazing. Grasses spread long distances easily, are hard to kill once established, and able to modify environments to their advantage, making them some of the most effective colonizers and most successful groups of species on the planet.” [‘Otherlands: A World in the Making’, Thomas Halliday (Allen Lane, 2022, p.67).]

“They are the most economically important plant family, providing staple foods from domesticated cereal crops such as maizewheatricebarley, and millet as well as feed for meat-producing animals. They provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other grains 6%. Some members of the Poaceae are used as building materials (bamboothatch, and straw); others can provide a source of biofuel, primarily via the conversion of maize to ethanol.” [Poaceae: Wikipedia.]

Grasses, sedges and rushes in the High Peak

For these buttons with the solid borders to work properly you will need to be registered and logged into iNaturalist. This is a free and extremely useful app. See our ‘How to record wildlife’ page for more information and tips on how to use it.

Takes you to the up-to-date list and photo galleries of all grass observations within the High Peak area, as recorded on iNaturalist

Takes you to the up-to-date list and photo galleries of all grass observations within the High Peak area, as recorded on iNaturalist

Takes you to the up-to-date list and photo galleries of all sedge observations within the High Peak area, as recorded on iNaturalist

Takes you to the up-to-date list and photo galleries of all sedge observations within the ‘Buxton polygon’ area, as recorded on iNaturalist and collected by the Buxton Biodiversity Recording Group project

Takes you to the up-to-date list and photo galleries of all rush observations within the ‘Buxton polygon’ area, as recorded on iNaturalist and collected by the Buxton Biodiversity Recording Group project

Takes you to the up-to-date list and photo galleries of all rush observations within the ‘Buxton polygon’ area, as recorded on iNaturalist and collected by the Buxton Biodiversity Recording Group project

Grass: Crested Dogstail (L Moon)
Grass: Crested Dogstail (L Moon)
Hairy brome, Millers Dale (D Purchase)

Photos of grass, sedge and rush species needed

Identifying grasses, sedges and rushes

Grasses, sedges and rushes can be difficult to identify, especially for beginners. The more detailed, classic guides tend to use technical terminology that can be daunting to beginners, and drawings that, while beautiful in their own right, beginners and more experienced users may find difficult to match to the specimens they see before them. There are an increasing number of excellent starter guides available that use high quality colour photos and less technical identification keys.

Guide to common grasses

FSC

FSC

One of the Field Studies Council’s excellent series of laminated fold-out guides. An very useful starter guide that fits easily in your pack or larger pockets. Coloured drawings.

A Field Guide to Grasses, Sedges and Rushes

Dominic Price

The Species Recovery Trust

Excellent user-friendly spiral bound guide for beginners. Colour photos.

Start to Identify Grasses

Faith Anstey

Faith Anstey

Very good self-published starter guide. Colour photos.

Start to Identify Sedges and Rushes

Faith Anstey

Faith Anstey

Very good self-published starter guide. Colour photos.

Grasses: A guide to their Structure, Identification, Uses and Distribution in the British Isles

C.E. Hubbard

Revised by J.C.E. Hubbard

Penguin

Comprehensive and detailed. B&W line drawings.

Collins Guide to the Grasses, Sedges, Rushes and Ferns of Britain and Northern Europe

Richard Fitter, Alastair Fitter, Ann Farrer

Collins

Collins classic series of field guides. Technical terminology. Colour and B&W drawings.

Information and guidance

Here are 2 very useful and instructive videos on identifying grasses, by the National Plant Monitoring Scheme (NPMS) and 2 interesting and informative video webinars on grasses and grasslands as climate solutions by Plantlife.

Classes for Grasses Episode 1: Grass Structure and Anatomy, by NPMS.

Classes for Grasses Episode 2: The Usual Suspects and Growth Form, by NPMS.

Fall into Nature: Classes for Grasses, by Sarah Shuttleworth of Plantlife.

Grasslands as a Climate Solution: Webinar by Plantlife