Archaeophytes are non-native (alien) taxa that were introduced by humans, either intentionally or unintentionally, and became naturalised in Britain and Ireland between the start of the Neolithic period and AD1500. Most were introduced by early farmers mainly in the Late Bronze Age, Iron Age, Roman or Medieval periods. Many originated as contaminants of crops or as escapes from gardens where they were grown for culinary or medicinal uses.

The rediscovery of the New World around AD1500 brought about radical changes in human demography, agriculture, trade and industry. It therefore marks an appropriate date to differentiate between ancient and modern introductions; those introduced before AD1500 were usually associated with food production whereas those that came after (neophytes) are mainly garden ornamentals and trees used for forestry.

Although the concept of archaeophytes has a long history in Europe, Preston et al. (2004) were the first workers to carry out a critical assessment of those present in Britain and Ireland. They used the following six criteria to identify probable archaeophytes:

  1. A lack of fossil evidence before the Neolithic period
  2. A preference for man-made habitats
  3. Documentary evidence of occurrence in the wild before AD1700
  4. Stable ranges since AD1700 or an increase/decline in response to environmental changes but not having expanded rapidly in new habitats
  5. An uncertain native range in Europe
  6. Likely to have also spread to ‘neo-Europe’ (Australia, New Zealand, North America)

Preston et al. (2004) produced a list of 157 probable archaeophytes including 150 species, 4 subspecies and 3 hybrids. They also listed a further 30 species which were certainly being grown in Britain before AD1500 that are rarely or never naturalised i.e. mainly occurring as crop relics and casuals. In addition, they included a list of 76 species regarded as doubtfully native in Britain but as an archaeophyte or probable archaeophyte elsewhere in Europe. They concluded that “These species are of particular interest as they may contain further taxa which should be considered as archaeophytes in Britain.”

Williamson et al. (2008) enumerate the numbers of archaeophytes included in Preston et al. (2004) that occur in Ireland either as archaeophytes (96 species) or casuals (30 species).

In their list of archaeophytes in Britain and Ireland, Stace & Crawley (2015) used a broader definition including an additional 45 taxa including the 30 species grown in Medieval gardens listed by Preston et al. (2004), 11 infraspecific taxa, 2 trees (walnut Juglans regia, pear Pyrus pyraster), Primitive Wheats Triticum spp. and Grape Vitis vinifera. In comparison to Preston et al. (2004) they differentiate three sub-groups of archaeophytes:

  1. Denizen: having the appearance of being native (i.e. fully naturalised) but with some suspicion of having been originally introduced, e.g. ground elder Aegopodium podagraria.  There are 87 species in this category.
  2. Colonist: almost exclusively confined to disturbed, anthropogenic habitats (cultivated land, roadsides or habitations), e.g. corncockle Agrostemma githago. There are 65 species in this category.
  3. Cultivated: crops or their derivatives that escape or persist, e.g. horseradish Armoracia rusticana. There are 45 species in this category.

It should be noted that many archaeophytes declined dramatically in Britain during the twentieth century. These includes several arable species that are now extinct (lamb's succory Arnoseris minima, stiking hawk's-beard Crepis foetida, small bur-parsley Caucalis platycarpos, narrow-leaved cudweed Filago gallica, downy hemp-nettle Galeopsis segetum, violet horned-poppy Roemeria hybrida) or nearly so (corn cleavers Galium tricornutum, darnel Lolium temulentum) due to improved seed cleaning and increased use of herbicides. Several more are extinct in arable habitats but survive elsewhere as casuals due to deliberate sowing in ‘wildflower mixtures’ (e.g. corncockle Agrostemma githago, thorow-wax Buplureum rotundifolium, cornflower Centaurea cyanus). As pointed out by Preston et al. (2004) these are best treated as neophyte occurrences.

The table below includes the list of archaeophytes for Britain and Ireland produced by Preston et al. (2004) and the update by Stace & Crawley (2015) to include cultivated species introduced before 1500. It also includes the list of archaeophytes for the island of Ireland produced by Williamson et al. (2008).

Scientific name (Stace 2019) English name Family Preston et al. (2004) Williamson et al. (2008) Stace & Crawley (2015) Comment
Adonis annua Pheasant’s-eye Ranunculaceae yes colonist
Aegopodium podagraria Ground-elder Apiaceae yes yes denizen
Aethusa cynapium subsp. agrestis Fool’s parsley Apiaceae colonist
Agrostemma githago Corncockle Caryophyllaceae yes casual colonist Extinct as archaeophyte; occurs widely as a casual due to seed sowing
Agrostis gigantea Black bent Poaceae yes yes denizen
Alcea rosea Hollyhock Malvaceae cultivated
Allium ampeloprasum Wild leek Amaryllidaceae yes yes denizen
Allium cepa Onion Amaryllidaceae cultivated
Allium porrum Leek Amaryllidaceae cultivated
Allium sativum Garlic Amaryllidaceae cultivated
Alopecurus myosuroides Black-grass Poaceae yes casual colonist
Anagallis arvensis subsp. foemina Blue pimpernel Primulaceae yes casual colonist
Anchusa arvensis Bugloss Boraginaceae yes yes denizen
Anethum graveolens Dill Apiaceae cultivated
Anisantha sterilis Barren brome Poaceae yes yes denizen
Anthemis arvensis Corn chamomile Asteraceae yes casual colonist
Anthemis cotula Stinking chamomile Asteraceae yes yes colonist
Anthriscus cerefolium Garden chervil Apiaceae cultivated
Apera spica-venti Loose silky-bent Poaceae yes casual colonist
Arctium lappa Greater burdock Asteraceae yes yes denizen
Armoracia rusticana Horse-radish Brassicaceae yes cultivated
Arnoseris minima Lamb’s succory Asteraceae yes yes colonist Extinct; last recorded in 1971
Artemisia absinthium Wormwood Asteraceae yes yes denizen
Artemisia vulgaris Mugwort Asteraceae yes yes denizen
Asparagus officinalis subsp.officinalis Garden asparagus Asparagaceae yes yes cultivated
Atriplex hortensis Garden orache Chenopodiaceae cultivated
Avena fatua Wild-oat Poaceae yes yes colonist
Avena sativa Oat Poaceae cultivated
Avena strigosa Bristle oat Poaceae cultivated
Ballota nigra Black horehound Lamiaceae yes yes denizen
Borago officinalis Borage Boraginaceae cultivated
Brassica rapa Turnip Brassicaceae yes yes
Brassica rapa subsp. campestris Wild turnip Brassicaceae denizen
Brassica rapa subsp. rapa Turnip Brassicaceae cultivated
Briza minor Lesser quaking-grass Poaceae yes casual colonist
Bromus secalinus Rye brome Poaceae yes casual colonist
Bupleurum rotundifolium Thorow-wax Apiaceae yes colonist Extinct as archaeophyte; occurs widely as a casual due to seed sowing
Calendula officinalis Pot marigold Asteraceae cultivated
Camelina sativa Gold-of-pleasure Brassicaceae yes casual colonist
Campanula rapunculus Rampion bellflower Campanulaceae yes denizen
Cannabis sativa Hemp Cannabaceae cultivated
Capsella bursa-pastoris Shepherd’s-purse Brassicaceae yes yes colonist
Carum carvi Caraway Apiaceae yes casual cultivated
Castanea sativa Sweet chestnut Fagaceae yes casual cultivated
Caucalis platycarpos Small bur-parsley Apiaceae yes colonist Extinct; last recorded in 1971
Centaurea calcitrapa Red star-thistle Asteraceae yes denizen
Centaurea cyanus Cornflower Asteraceae yes yes colonist Extinct as archaeophyte; occurs widely as a casual due to seed sowing
Chaenorhinum minus Small toadflax Veronicaceae yes yes colonist
Chelidonium majus Greater celandine Papaveraceae yes yes denizen
Chenopodium bonus-henricus Good-King-Henry Chenopodiaceae yes yes denizen
Chenopodium ficifolium Fig-leaved goosefoot Chenopodiaceae yes casual colonist
Chenopodium glaucum Oak-leaved goosefoot Chenopodiaceae yes casual denizen
Chenopodium hybridum Maple-leaved goosefoot Chenopodiaceae yes colonist
Chenopodium murale Nettle-leaved goosefoot Chenopodiaceae yes yes denizen
Chenopodium polyspermum Many-seeded goosefoot Chenopodiaceae yes yes colonist
Chenopodium urbicum Upright goosefoot Chenopodiaceae yes colonist
Chenopodium vulvaria Stinking goosefoot Chenopodiaceae yes denizen
Cicer arietinum Chick pea Fabaceae cultivated
Cichorium intybus Chicory Asteraceae yes yes denizen
Conium maculatum Hemlock Apiaceae yes yes denizen
Coriandrum sativum Coriander Apiaceae cultivated
Crepis foetida Stinking hawk’s-beard Asteraceae yes colonist Extinct; reintroduced in Kent
Cuminum cyminum Cumin Apiaceae cultivated
Descurainia sophia Flixweed Brassicaceae yes yes denizen
Diplotaxis tenuifolia Perennial wall-rocket Brassicaceae yes casual denizen
Echium plantagineum Purple viper’s-bugloss Boraginaceae yes casual denizen
Erodium moschatum Musk stork’s-bill Geraniaceae yes yes denizen
Eruca vesicaria subsp. sativa Garden rocket Brassicaceae cultivated
Eryngium campestre Field eryngo Apiaceae yes denizen
Erysimum cheiranthoides Treacle-mustard Brassicaceae yes yes colonist
Erysimum cheiri Wallflower Brassicaceae yes yes denizen
Euphorbia exigua Dwarf spurge Euphorbiaceae yes yes colonist
Euphorbia helioscopia Sun spurge Euphorbiaceae yes yes colonist
Euphorbia lathyris Caper spurge Euphorbiaceae yes yes denizen
Euphorbia peplus Petty spurge Euphorbiaceae yes yes colonist
Euphorbia platyphyllos Broad-leaved spurge Euphorbiaceae yes colonist
Fallopia convolvulus Black-bindweed Polygonaceae yes yes colonist
Filago gallica Small cudweed Asteraceae yes colonist Extinct; reintroduced in Essex. Also survives in the Channel Islands
Filago pyramidata Broad-leaved cudweed Asteraceae yes denizen
Foeniculum vulgare Fennel Apiaceae yes casual denizen
Fumaria densiflora Dense-flowered fumitory Papaveraceae yes colonist
Fumaria officinalis Common fumitory Papaveraceae yes yes
Fumaria officinalis subsp. officinalis Common fumitory Papaveraceae colonist
Fumaria officinalis subsp. wirtgenii Common fumitory Papaveraceae colonist
Fumaria parviflora Fine-leaved fumitory Papaveraceae yes colonist
Fumaria vaillantii Few-flowered fumitory Papaveraceae yes colonist
Galeopsis angustifolia Red hemp-nettle Lamiaceae yes yes denizen
Galeopsis segetum Downy hemp-nettle Lamiaceae yes colonist
Galeopsis speciosa Large-flowered Lamiaceae yes yes colonist Extinct; last recorded in 1975
Galium tricornutum Corn cleavers Rubiaceae yes colonist Survives on an experimental plot in Hertfordshire; reintroduced to a site in Oxfordshire
Geranium dissectum Cut-leaved crane’s-bill Geraniaceae yes yes denizen
Glebionis segetum Corn marigold Asteraceae yes yes colonist
Helminthotheca echioides Bristly oxtongue Asteraceae yes denizen
Hordeum distichon Two-rowed barley Poaceae cultivated
Hordeum murinum Wall barley Poaceae yes yes denizen
Hordeum vulgare Six-rowed barley Poaceae cultivated
Hyoscyamus niger Henbane Solanaceae yes yes denizen
Imperatoria ostruthium Masterwort Apiaceae yes yes denizen
Inula helenium Elecampane Asteraceae yes yes denizen
Isatis tinctoria Woad Brassicaceae yes casual cultivated
Juglans regia Walnut Juglandaceae cultivated
Kickxia elatine Sharp-leaved fluellen Veronicaceae yes yes colonist
Kickxia spuria Round-leaved fluellen Veronicaceae yes colonist
Lactuca sativa Garden lettuce Asteraceae cultivated
Lactuca serriola Prickly lettuce Asteraceae yes casual denizen
Lamium album White dead-nettle Lamiaceae yes yes denizen
Lamium amplexicaule Henbit dead-nettle Lamiaceae yes yes colonist
Lamium confertum Northern dead-nettle Lamiaceae yes colonist
Lamium hybridum Cut-leaved dead-nettle Lamiaceae yes yes colonist
Lamium purpureum Red dead-nettle Lamiaceae yes yes colonist
Legousia hybrida Venus’s-looking-glass Campanulaceae yes colonist
Lens culinaris Lentil Fabaceae cultivated
Lepidium campestre Field pepperwort Brassicaceae yes casual denizen
Lepidium coronopus Swine-cress Brassicaceae yes yes denizen
Lepidium ruderale Narrow-leaved pepperwort Brassicaceae yes casual denizen
Lepidium sativum Garden cress Brassicaceae cultivated
Linaria repens Pale toadflax Veronicaceae yes yes denizen
Linum usitatissimum Flax Linaceae cultivated
Lithospermum arvense Field gromwell Boraginaceae yes colonist
Lolium temulentum Darnel Poaceae yes casual colonist Possibly only on the Aran Islands, Ireland
Lythrum hyssopifolia Grass-poly Lythraceae yes casual denizen
Malus pumila Apple Rosaceae yes yes denizen
Malva neglecta Dwarf mallow Malvaceae yes yes denizen
Malva sylvestris Common mallow Malvaceae yes yes denizen
Matricaria chamomilla Scented mayweed Asteraceae yes casual denizen
Melilotus altissimus Tall melilot Fabaceae yes yes denizen
Mentha spicata Spear mint Lamiaceae yes yes denizen
Mercurialis annua Annual mercury Euphorbiaceae yes yes denizen
Mespilus germanica Medlar Rosaceae yes denizen
Misopates orontium Weasel’s-snout Veronicaceae yes yes colonist
Myosotis arvensis Field forget-me-not Boraginaceae yes yes denizen
Nepeta cataria Cat-mint Lamiaceae yes denizen
Onopordum acanthium Cotton thistle Asteraceae yes casual denizen
Papaver argemone Prickly poppy Papaveraceae yes yes colonist
Papaver dubium Long-headed poppy Papaveraceae yes yes colonist
Papaver hybridum Rough poppy Papaveraceae yes casual colonist
Papaver lecoqii Yellow-juiced poppy Papaveraceae colonist
Papaver rhoeas Common poppy Papaveraceae yes yes colonist
Papaver somniferum Opium poppy Papaveraceae yes casual cultivated
Petroselinum crispum Garden parsley Apiaceae yes yes cultivated
Pisum sativum Garden pea Fabaceae cultivated
Polygonum arenastrum Equal-leaved knotgrass Polygonaceae yes yes denizen
Polygonum rurivagum Cornfield knotgrass Polygonaceae yes casual colonist
Portulaca oleracea Common purslane Portulacaceae cultivated
Prunus cerasus Dwarf cherry Rosaceae yes yes denizen
Prunus domestica Plum Rosaceae yes yes
Prunus domestica subsp. domestica Plum Rosaceae denizen
Prunus domestica subsp. insititia Damson, Bullace Rosaceae cultivated
Prunus domestica subsp. italica Greengage Rosaceae cultivated
Pyrus communis s.l. Pear Rosaceae yes casual cultivated
Pyrus pyraster Wild pear Rosaceae denizen
Ranunculus arvensis Corn buttercup Ranunculaceae yes colonist
Raphanus raphanistrum subsp.raphanistrum Wild radish Brassicaceae yes yes colonist
Raphanus sativus Garden radish Brassicaceae cultivated
Reseda luteola Weld Resedaceae yes yes denizen
Roemeria hybrida Violet horned-poppy Papaveraceae yes denizen Extinct; possibly last recorded in Suffolk in 1956
Rumex alpinus Monk’s rhubarb Polygonaceae yes denizen
Salix alba White willow Salicaceae yes casual denizen
Salix alba × S. euxina Crack-willow Salicaceae yes yes denizen
Salix triandra Almond willow Salicaceae yes yes denizen
Salix triandra × S. viminalis Sharp-stipuled willow Salicaceae yes yes denizen
Salix viminalis Osier Salicaceae yes yes denizen
Sambucus ebulus Dwarf elder Caprifoliaceae yes yes denizen
Saponaria officinalis Soapwort Caryophyllaceae yes yes denizen
Scandix pecten-veneris Shepherd’s-needle Apiaceae yes colonist
Secale cereale Rye Poaceae cultivated
Sedum album White stonecrop Crassulaceae yes yes denizen
Silene gallica Small-flowered catchfly Caryophyllaceae yes yes denizen
Silene latifolia White campion Caryophyllaceae yes yes denizen
Silene noctiflora Night-flowering catchfly Caryophyllaceae yes casual colonist
Silybum marianum Milk thistle Asteraceae yes yes denizen
Sinapis alba White mustard Brassicaceae yes yes colonist
Sinapis arvensis Charlock Brassicaceae yes yes denizen
Sisymbrium officinale Hedge mustard Brassicaceae yes yes denizen
Smyrnium olusatrum Alexanders Apiaceae yes yes denizen
Spinacia oleracea Spinach Chenopodiaceae cultivated
Stachys arvensis Field woundwort Lamiaceae yes yes colonist
Tanacetum parthenium Feverfew Asteraceae yes yes denizen
Thlaspi arvense Field penny-cress Brassicaceae yes yes colonist
Torilis arvensis Spreading Apiaceae yes colonist
Trigonella foenum-graecum Fenugreek Fabaceae cultivated
Tripleurospermum inodorum Scentless mayweed Asteraceae yes yes denizen
Triticum aestivum Bread wheat Poaceae cultivated
Triticum species (T. dicoccon, T. compactum, T. monococcum, T. spelta) Primitive wheats Poaceae cultivated
Urtica urens Small nettle Urticaceae yes yes denizen
Valerianella carinata Keeled-fruited cornsalad Valerianaceae yes yes denizen
Valerianella dentata Narrow-fruited cornsalad Valerianaceae yes casual colonist
Valerianella rimosa Broad-fruited cornsalad Valerianaceae yes colonist
Verbena officinalis Vervain Verbenaceae yes yes denizen
Veronica agrestis Green field-speedwell Veronicaceae yes yes denizen
Veronica hederifolia Ivy-leaved speedwell Veronicaceae yes yes
Veronica hederifolia subsp. hederifolia Ivy-leaved speedwell Veronicaceae denizen
Veronica hederifolia subsp. lucorum Ivy-leaved speedwell Veronicaceae denizen
Veronica triphyllos Fingered speedwell Veronicaceae yes denizen
Vicia faba Broad bean Fabaceae cultivated
Vicia sativa subsp. sativa Common vetch Fabaceae yes yes cultivated
Vicia sativa subsp. segetalis Common vetch Fabaceae yes yes denizen
Vinca minor Lesser periwinkle Apocynaceae yes yes denizen
Viola arvensis Field pansy Violaceae yes yes denizen
Vitis vinifera Grape-vine Vitaceae cultivated
Vulpia myuros Rat’s-tail fescue Poaceae yes yes denizen