When used without any additional description or qualification, ‘wild flower’ is taken to mean a plant indigenous to the country or region in which it is being referred to.

It may be argued that ‘wild flower’ could also be applied to naturalised plants as well as native. Naturalised plants are those that have been introduced into the wild through human agency and become established there. Most modern Floras of the UK include such plants. For example, the Californian poppy (Eschscholzia californica), among many other non-native plants, is listed as ‘introduced or naturalised’ in the New Flora of the British Isles (Stace, 2010).

There are some plants which, though introduced, have been naturalised from ancient times up to the discovery of the New World (c. 1500, see definitions). Examples that may be found in many wildflower mixes include corn cockle (Agrostemma githago), common poppy (Papaver rhoeas), night-flowering catchfly (Silene noctiflora), corn marigold (Glebionis segetum) and corn chamomile (Anthemis arvensis).

In the context of garden use and horticulture we recommend that:

1. For greater clarity, when offering ‘wild flower’ plants or seeds for sale, we suggest that ‘wild flower’ is only applied to those plants considered natives or pre-1500 (see Preston et al., 2004) introductions but not to more recently naturalised plants. When applied in the UK, to ensure there is no ambiguity, the use of the more complete description ‘British wild flower’ is advisable on labelling or sales material. Where the plants or seeds are being sold to reflect a more regional origin, then the relevant region should be indicated, particularly where some of the species included are not considered native to other regions of the British Isles.
2. If plants are neither natives nor pre-1500 introductions, it would be desirable to use alternative descriptions or selling names (examples on the market include ‘urban meadow’, ‘flowering meadow’, ‘ornamental meadow’ and ‘Pictorial Meadows™’ or suggested terms such as ‘cultivated annuals’, ‘cultivated perennials’ or ‘cultivated mix’) where relevant. More specific terms, such as ‘prairie wildflowers’ for certain North American mixes, could be used.
3. Where there is a mix of native/pre-1500 introductions and non-native species, or native/pre-1500 introductions and cultivated selections of natives (i.e. cultivars), this should be made clear in the description.
4. Irrespective of terminology, a sensible and precautionary approach would be to list all the species of plant present in the mix (or to refer to a website where this list can be found).
5. That the provenance of seed should be indicated to allow people to make an informed choice. This should indicate whether the seed is sourced from plants growing in the UK or abroad. In cases with seed from many sources, it is suggested that ‘product of more than one country’ is included on the label.

The definition of native plants followed here was provided by Pyšek et al. (2004) (see references) and is as follows, “Taxa that have originated in a given area without human involvement or that have arrived there without intentional or unintentional intervention of humans from an area in which they are native.” Stace (2010) is a standard reference against which the native status of plants occurring in the British Isles can be checked.

Plants introduced prior to 1500 are referred to as archaeophytes following the definition provided by Preston et al. (2004) where the concept was introduced and where a comprehensive list of the UK plants that are considered archaeophytes can be found.

The term provenance is used in this guidance to refer to where plants from which the seed was harvested were grown. It is not the same as ‘origin’ which in this context means the original geographic source of the plants which may be many generations back from the most recent harvest.

Archaeophytes in Britain by Christopher D. Preston, David A. Pearman, Allan R. Hall. (2004 Botanical Journal of the Linnean Society 145: 257-294)

Alien plants in checklists and floras: towards better communication between taxonomists and ecologists by Pyšek, P., Richardson, D. M., Rejmánek, M., Webster, G. L., Williamson, M., Kirschner, J. (2004 Taxon 53 (1): 131-143)

New Flora of the British Isles (3rd edition) by Stace, C. (2010 Cambridge: Cambridge University Press)