Plant identification

Introduction

The identification of plants has always been one of the most popular benefits of RHS membership. While the emphasis is naturally on garden plants, staff in the Botany Department also identify problem weeds, as well as plants seen on holidays abroad. For non-members and members alike, there are various self-help possibilities.

How to attempt to identify a plant

1 Comparison: labelled plants in a garden open to the public or well-illustrated books can give useful leads. Cultivar identification, in particular, is amenable to this approach. Several of the books by Phillips & Rix provide good starting points, and are widely available. Some gardening magazines carry review features on plant groups: it is certainly worth keeping those back issues of The Garden ! Be aware that plants in gardens (and in books) may not be correctly labelled!

2 Books: use of keys with associated descriptions. Keys are daunting at first, but enable you to tackle the problem of identification in a systematic and logical way. They can be helpful where a plant is completely unknown, but also for improving the identification of, for instance, a Hebe to its species, or a border penstemon to its cultivar (though cultivar keys are much less common, and often rely upon characteristics such as colour which are very difficult to describe). The European Garden Flora is a comprehensive starting point and bridges the gap between the scientific literature and the layman's guide with reasonably familiar terminology. One warning: keys are often hopeless for identifying a less-than-complete specimen (i.e. one with flowers and foliage, plus an idea of the height, habit and origin of the overall plant from which a sample has been taken).

3 Ask an expert: Many garden centres and nurseries are very helpful indeed; some botanic gardens and universities with Botany Departments are prepared to help. RHS members may obtain help in this and other matters through the RHS Advisory Service . You could even try posting a picture of your plant onto one of the popular gardening discussion groups online. It is always helpful to note down as many details of the plant as you can before asking a specialist - it makes their job so much easier.

Further reading

Some useful books for identifying plants

RHS Plant Finder bibliography (250KB PDF)

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