How do I start to identify plants?

The variety of plants around us wherever we are is amazing. They are beautiful and fascinating, but if you want to identify which ones are which, how and where do you start?

Grouping plants

All living things are classified scientifically into groups and named. The science of doing this is called taxonomy.

The species is the basic taxonomic unit. A species is an individual type of plant e.g. Ranunculus repens, creeping buttercup. Members of a species are very similar to each other and can interbreed, but cannot usually interbreed with another species.

Ranunculus repens – creeping buttercup

Closely-related species are grouped into genera (sing. genus), and closely-related genera are grouped into families based on characteristics that they share. Buttercups belong to the Ranunculaceae family. Getting to know plant families is great way to begin plant identification. There are many plant families but some are small or not important in the British Isles, so it is best to start by focusing on the large families of flowering plants that are well-represented in Britain. As you get to know their distinguishing characters you will find you have only to glance at a plant and you will know its family.

Plant names

Each species (individual type) of plant has been given a scientific name and most also have a common name; many plants have more than one common name. The scientific or botanical name has two parts: the genus and the specific epithet. Together these make up the species name.

In our buttercup example, Ranunculus is the genus, the group to which all buttercups belong and repens is the specific epithet; Ranunculus repens is the species name. Creeping buttercup is the English common name.

Names can often tell you something about a plant – for instance, ‘repens‘ means ‘creeping’. Plant names do sometimes change from time to time, reflecting the latest research.

What to look at

Plant parts and characters to look at when identifying plants:

Flowers – arguably the most important for identification; the flowers of many families are distinctive and you can soon learn to recognise daisy flowerheads or pea flowers, for example. The taxonomic grouping of plants is very dependent on floral characters. Look at the number of petals, whether they are joined together and their colour. Look at the numbers and appearance of the stamens and the stigmas.

Leaves – are they simple or compound? What shape are they? Do they grow in opposite pairs or do they alternate up the stems? Maybe they form a flat rosette.

Stems – see if the stems branch or not, if they have hairs or ridges and what shape they are (round, square, flattened?).

Fruits – formed from the pollinated flowers, these come in many different types; dry, fleshy, splitting open like a pod or staying whole like a nut; they may be adorned with parachutes, hooks or bright colours.

Overall appearance – how big is the plant? Is it tiny and low, tall and elegant, bushy? See what colours are found on the flowers, leaves, stems.

Textures – some plants are sticky, spiny, rough or soft and woolly.

Scents – gently rubbing the leaves of some plants releases a distinctive scent. Some of these scents are pleasant (water mint perhaps?), others not so much (hedge woundwort, once smelled, is not easily forgotten).

Be aware that some plants do contain poisonous compounds, so take care if you’re handling unknown plants and wash your hands afterwards.

Some plants are easy to identify, while some require close inspection and a key to get down to species level. Start with common plants that have large showy flowers. We recommend that you get yourself a hand lens for magnifying small features like hairs and flower structures. A lens really is invaluable when examining plants. They come in different magnifications (try a x20) and can often be found cheaper by searching for ‘jeweller’s loupe’ rather than ‘botanist hand lens’.

Try to identify plants without picking if possible, and remember that it is against the law to uproot plants without landowner permission. Have a look at this Code of Conduct on picking, collecting, photographing and enjoying wild plants from the BSBI for good guidance.

Field guides and keys

Field guides are essential for plant identification and there are many to choose from. These books generally contain descriptions of plants (habit, leaves, flowers, fruits and so on) with accompanying images, either illustrations or photos. We recommend that you acquire one of these before you embark on identifying plants in the field.

People tend to have certain field guides that they prefer, so it’s worth trying a few if you can, to see which you get on with best. Here’s a selection that we like:

The Wild Flower Key by Francis Rose
Wild Flowers of Britain and Ireland by Blamey, Fitter and Fitter
Collins Wild Flower Guide by Streeter, Hart-Davies, Hardcastle, Cole and Harper

Field guides can be used in a number of ways. Some have the plants organised by flower colour, which can be useful when you are just starting out. Many are arranged by family, so once you learn to identify which family a plant belongs to you can skip straight to the right section of the book. Many field guides also contain keys, which can take a bit of getting used to but are extremely useful once you can use them. These keys use pairs of sentences describing aspects of plant species: following the most appropriate half of the couplets should lead you to the correct species. You should always read the descriptions of the plants in field guides as well as looking at the illustrations to make sure you have the right one.

Clive Stace’s New Flora of the British Isles is a work of reference that serious botanists eventually tend to turn to. It can be used like a dictionary and defines all the species that you may encounter. There is no colour, only a few line drawings and monochrome photos. If you get the 4th edition, the plant names are up-to-date.

There are also apps available that act as field guides or suggest plant names from photos you take.

Plant family identification videos

We are working on a series of videos on identifying plant families. These simple videos aim to help you learn how to identify common UK plant families in (more or less) five minutes each.

The video below looks at the Lamiaceae family, the dead-nettle family, which contains species such as white dead-nettle (Lamium album) and ground ivy (Glechoma hederacea).

This next video looks at the Apiaceae family, the carrot family, which includes species like common hogweed (Heracleum sphondylium) and ground elder (Aegopodium podagraria).

Other videos available so far in this series are:
Asteraeae (daisy family)
Brassicaceae (cabbage family)
Fabaceae (pea family)
Boraginaceae (borage family)
Rosaceae (rose family)
Ranunculaceae (buttercup family)
Geraniaceae (geranium family)
Rubiaceae (bedstraw family)

Plant ecology

Some plants are more likely to be found in certain places, because they are adapted to particular soil conditions or germinate well under certain circumstances, for instance. This can be a useful guide, though many plants are able to grow in a range of environments and soil conditions, so it’s not a hard-and-fast way of confirming species. With practise, you will come to know which plants you might expect to find in certain habitats and which plants you are likely to find together.

e.g. sanicle (Sanicula europaea) is usually found in broadleaved woodlands; hairy bittercress (Cardamine hirsuta) springs up where the ground has been disturbed; meadowsweet (Filipendula ulmaria) is found in damp places and beside water.

Meadowsweet (Filipendula ulmaria)
More identification resources

Some of these resources have been developed by BSS members.

– We are featuring one species each week as Plant of the Week, usually one that’s flowering now (see the main blog)

– We usually run a beginner’s identification workshop in May and hold field meetings throughout the summer; keep an eye on the blog and our website for details of future events

– Richard Milne has developed a web site on plant ID for his students at Edinburgh University, with a family finder key and a downloadable poster showing the relationships of the world’s vascular plants. Check it out at Milneorchid’s Botany Site

– Lyn Jones of Dundee University has made a visual key: you click on pictures and it leads you to the species. Try it here and maybe install the app on your phone. There are several apps like this to chose from; look at a recent review by Lyn here and, if you like, you can watch a lecture by Hamlyn Jones about the use of apps for plant id on our YouTube channel.

– Or try iSpot, developed several years ago by Jonathan Silvertown when he was at the Open University. You can upload a photo of any plant (or animal/fungus) and people will help you identify it, sometimes very quickly

– Our friends at the Botanical Society of the British Isles have compiled many resources as well: investigate them here

– The BSS has a Facebook page where you can upload images of unknown plants for us to identify. We are thinking of starting a special Facebook page where members may upload images and we will try to identify them. If you might use this then please tell us

Are there any other articles or videos on plant identification that you would find useful? Feel free to let us know!

Images by Heather Forbes

Common plants – edges and hedges (part 2)

These species are commonly found growing at the side of paths and buildings and at the foot of hedges. Keep an eye out in other places too, though, because they grow in other places as well. Here we look at chickweed, garlic mustard, white dead-nettle and stinging nettle.

Common plants – walls

These species are commonly found growing on or out of walls in urban areas. Here we look at wall rue, maidenhair spleenwort, ivy-leaved toadflax and hart’s-tongue fern.

Common plants – garden escapes

These species are commonly found growing at the side of paths, roads and other places near human habitation. They are introduced plants that have escaped from cultivation. Here we look at Welsh poppy, yellow archangel, lady’s-mantle and purple toadflax.

Common fungi – rust fungi

These fungi are usually host specific, only infecting particular plant species. Look out for any plants that appear a bit sickly or have distortions – they may well be infected with rust. Here we look at rusts found on nettle, creeping thistle, comfrey and groundsel.

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