Nigel Cattlin / Scarlet pimpernel (Anagallis arvensis) growing as arable weed. England, UK. September.

Nigel Cattlin / Common knotgrass (Polygonum aviculare) growing as arable weed. England, UK. August.

Nigel Cattlin / Redshank (Persicaria maculosa) growing as arable weed. England, UK. September.

Nigel Cattlin / Redshank (Persicaria maculosa) growing as arable weed. England, UK. September.

Nigel Cattlin / Fat-hen (Chenopodium album) seedling with cotyledons and four true leaves, annual arable weed.

Nigel Cattlin / Cleavers (Galium aparine) seedling with cotyledons and early leaf rosettes, growing as garden weed.

Nigel Cattlin / Chickweed (Stellaria media) flowers amongst leaves, an annual arable weed. Berkshire, England, UK. August.

Nigel Cattlin / Black nightshade (Solanum nigrum) flowering and with unripe berries, an annual arable weed. Berkshire, England, UK. August.

Nigel Cattlin / Chickweed (Stellaria media), an annual arable weed. Berkshire, England, UK. August.

Nigel Cattlin / Chickweed (Stellaria media), an annual arable weed. Berkshire, England, UK. August.

Nigel Cattlin / Broad-leaved willowherb (Epilobium montanum) seedpods opening to disperse seeds, an arable weed. Berkshire, England, UK. August.

Nigel Cattlin / Redshank (Persicaria maculosa), an annual arable weed. Berkshire, England, UK. August.

Nigel Cattlin / White dead-nettle (Lamium album) seedling with two cotyledons and two true leaves. A garden and arable agricultural weed.

Andy Sands / Pheasant's eye (Adonis amurensis) arable weed in full bloom, Hertfordshire, England, UK, May

Andy Sands / Pheasant's eye (Adonis amurensis) arable weed in full bloom, Hertfordshire, England, UK, May - Focus Stacked

Andy Sands / Broad-fruited cornsalad (Valerianella rimosa) Very rare arable weed, Hertfordshire, England, UK, May

Paul Harcourt Davies / Poppies (Papaver rhoeas) two flowers and developing seed pod, near Castellucio di Norcia, Umbria, Italy, July.

Paul Harcourt Davies / Poppies (Papaver rhoeas), Cornflowers (Centaurea cyanus) and Chamomile (Anthemis arvensis) near Castellucio di Norcia, Umbria, Italy, July.

Paul Harcourt Davies / Poppies (Papaver rhoeas), cornflowers (Centaurea cyanus) and chamomile (Anthemis arvensis) near Castellucio di Norcia, Umbria, Italy. July.

Paul Harcourt Davies / Poppies (Papaver rhoeas) and cornflowers (Centaurea cyanus) near Castellucio di Norcia, Umbria, Italy, July.

Paul Harcourt Davies / Viper's bugloss (Echium vulgare) growing with Stachys sp, Melampyrum and others near Campo Imperatore, Abruzzo, Italy June.

Paul Harcourt Davies / Flowers Poppies (Papaver rhoeas), Camomile(white) Field cow heat (dark red) Stachys (greenish white) road from Campo Imperatore to Santa Stefano, Abruzzo, Italy June 2016

Paul Harcourt Davies / Field cow-wheat (Melampyrum arvense) Campo Imperatore, Abruzzo, Italy June 2016

Paul Harcourt Davies / Viper's bugloss (Echium vulgare) growing with Stachys sp, Melampyrum and others near Campo Imperatore, Abruzzo, Italy June 2016

Paul Harcourt Davies / Cornflowers (Centaurea cyanus) and other weeds of cultivated land near Castellucio di Norcia, Umbria, Italy, June.

Paul Harcourt Davies / Poppies (Papaver rhoeas) flowering in grassland near Castellucio di Norcia, Umbria, Italy, July.

Gary K. Smith / Tractor spraying herbicide to prevent weed growth in Sugarbeet (Beta vulgaris) crop, Norfolk, UK, April.

Andy Sands / Field Cow Wheat (Melampyrum arvense) growing abundantly among poppies - Field Cow Wheat is a rare arable weed. Bedfordshire, England, June.

Andy Sands / Field Cow Wheat (Melampyrum arvense) growing at edge of cornfield. This species is a rare, arable weed. Bedfordshire, England, UK, June.

Andy Sands / Pheasant's Eye (Adonis amurensis) flowering at edge of Cornfield, Bedfordshire, UK, June

Andy Sands / Knotted Hedge-Parsley (Torilis nodosa) close up of flower, an arable weed, Bedfordshire, England, UK, June

Andy Sands / Field Cow wheat (Melampyrum arvense) close up of flowers, growing at edge of cornfield. This species is a rare, arable weed. Bedfordshire, England, UK, May

Andy Sands / Field Cow wheat (Melampyrum arvense) in flower at edge of cornfield. This species is a rare, arable weed. Bedfordshire, England, UK, May

Andy Sands / Field Cow wheat (Melampyrum arvense) in flower at edge of cornfield. This species is a rare, arable weed. Bedfordshire, England, UK, May

Jason Smalley / Corncockle {Agrostemma githago} Poppy {Papaver sp.} and Marigold {Calendula sp.} growing on busy roundabout planted with arable weed mix, wildflower and wild meadow seed mix to attract wildlife, UK.

Jason Smalley / Corncockle {Agrostemma githago} Poppy {Papaver sp.} and Marigold {Calendula sp.} growing on busy roundabout planted with arable weed mix, wildflower and wild meadow seed mix to attract wildlife, UK.

Jason Smalley / Corncockle {Agrostemma githago} Poppy {Papaver sp.} and Marigold {Calendula sp.} growing on busy roundabout planted with arable weed mix, wildflower and wild meadow seed mix to attract wildlife, UK.

Jason Smalley / Corncockle {Agrostemma githago} Poppy {Papaver sp.} and Marigold {Calendula sp.} growing on busy roundabout planted with arable weed mix, wildflower and wild meadow seed mix to attract wildlife, UK.

Jason Smalley / Corncockle {Agrostemma githago} Poppy {Papaver sp.} and Marigold {Calendula sp.} growing on busy roundabout planted with arable weed mix, wildflower and wild meadow seed mix to attract wildlife, UK.

Jason Smalley / Corncockle {Agrostemma githago} Poppy {Papaver sp.} and Marigold {Calendula sp.} growing on busy roundabout planted with arable weed mix, wildflower and wild meadow seed mix to attract wildlife, UK.

Nigel Cattlin / Scarlet pimpernel (Anagallis arvensis), red flowering annual arable weed in waste ground, Berkshire, July

Nigel Cattlin / Field forget-me-not (Myosotis arvensis( annual arable weed growing in waste ground with scarlet pimpernel, Berkshire, July

Nigel Cattlin / Sun spurge (Euphorbia helioscopia) annual arable plant flowering in waste arable ground, Berkshire, July

Nigel Cattlin / Sun spurge (Euphorbia helioscopia) annual arable plant flowering in waste arable ground, Berkshire, July

Nigel Cattlin / Fat-hen / lamb's quarters (Chenopodium album) young plants of annual arable and garden weed, May Berkshire, England, UK.

Nigel Cattlin / Perennial sow-thistle / field sowthistle (Sonchus arvensis) plant rosette in waste cultivated ground, Berkshire, England, UK. July

Nigel Cattlin / Johnson grass (Sorghum halepense) tall, flowering weed panicles in a mature Maize (Zea mays) crop, Italy. July.

Nigel Cattlin / Blackgrass (Alopecurus myosuroides) seedling, arable annual grass weed with a single tiller.

Nigel Cattlin / Various annual broad-leaved weed seeds collected at harvest and contaminating barley cereal grain

Nigel Cattlin / Various annual broad-leaved weed seeds collected at harvest and contaminating barley cereal grain

Alex Hyde / Large-flowered hemp-nettle (Galeopsis speciosa) growing on field margin, a typical situation for this arable weed. Peak District National Park, Derbyshire, UK. August.

Nigel Cattlin / Cleavers (Galium aparine) seeds contaminating combine harvested Wheat (Triticum aestivum) grain, grain rejected in quality control.

Nigel Cattlin / Cleavers (Galium aparine) seeds contaminating combine harvested Wheat (Triticum aestivum) grain, grain rejected in quality control.

Nigel Cattlin / Wild oats (Avena fatua) annual arable grass weed flowering spikes in barley crop in green ear

Nigel Cattlin / Annual mercury (Mercurialis annua) flowering, an agricultural weed

Nigel Cattlin / Small white flowers of arable and garden weed cleavers (Galium aparine) and leaves with hooked hairs which stick to clothing

Nigel Cattlin / Onion couch or false oat grass (Arrhenatherum elatius) grass weed culms scattered on the soil after rotavation

Nigel Cattlin / Seedling Cleavers / Goosegrass (Galium aparine) annual arable and garden weed with cotyledons and first true whorl

Nigel Cattlin / Seedling Cleavers / Goosegrass (Galium aparine) annual arable and garden weed with cotyledons and first true leaves just forming

Nigel Cattlin / A seedling plant of Common orache (Atriplex patula) seedling weed with cotylledons and first two true leaves developing

Nigel Cattlin / A seedling of Forget-me-not (Myosotis, arvensis) an annual arable and garden weed with cotyledons and first true leaves

Nigel Cattlin / A seedling plant of Herb robert (Geranium robertianum) an annual plant of waste ground and gardens with cotyledons and first true leaves

Nigel Cattlin / Young plant of Fool's parsley (Aethusa cynapium) an annual arable and garden weed

Nigel Cattlin / Seedling Fool's parsley (Aethusa cynapium) cotyledons and first true leaves of annual arable and garden weed

Nigel Cattlin / A young Redshank plant (Polygonum maculosa) cotyledons and three true leaves of an annual weed of arable agriculture and gardens

Nigel Cattlin / Young prostrate Perennial sow-thistle (Sonchus arvensis) perennial young weed plants on arable ground, Berkshire, July

Nigel Cattlin / Black nightshade plant (Solanum nigrum) a young plant of an annual arable weed with several true leaves, Berkshire, July

Nigel Cattlin / Black nightshade plant (Solanum nigrum) young plant of an annual arable weed with cotyledons and four true leaves, Berkshire, July

Nigel Cattlin / Saltbush / Common orache (Atriplex patula) plant prostrate on cultivated fiield - a weed of gardens and arable crops Berkshire, England, UK.

Nigel Cattlin / Fat hen / Goosefoot (Chenopodium album) plant. An arable and garden weed and also a cultivated plant used in place of spinach Berkshire, England, UK.

Nigel Cattlin / Fat hen / Goosefoot (Chenopodium album) plant. An arable and garden weed and also a cultivated plant used in place of spinach Berkshire, England, UK.

Nigel Cattlin / Rayless mayweed / Pineappleweed (Matricaria discoidea) flowering weed in agricultural fallow ground Berkshire, England, UK.

Nigel Cattlin / Rayless mayweed / Pineappleweed (Matricaria discoidea) flowering weed in agricultural fallow ground, Berkshire, July

Nigel Cattlin / Couch grass rhizomes (Elymus repens), dug up from an established vegetable garden and capable of invasive regrowth Berkshire, England, UK.

Nigel Cattlin / Common amaranth / Pigweed (Amaranthus retroflexus) flowering plant, Gironde, France, August

Nigel Cattlin / Fat hen (Chenopodium album) seedling with cotyledons and two true leaves forming - an annual arable and garden weed

Nigel Cattlin / Seedling Stinging nettle (Urtica dioica) perennial stinging weed of gardens, wasteground and hedgerows with several true leaves

Nigel Cattlin / Seedling Broad leaved willowherb (Epilobium montanum) arable annual garden weed with four true leaves

Nigel Cattlin / Hairy bittercress (Cardamine hirsuta) young plant rosette on soil, Devon, England, UK, April.

Nigel Cattlin / Chickweed (Stellaria media) flowers and leaves of an annual agricultural and garden weed

Nigel Cattlin / Young flowering plant of hairy bittercress (Cardamine hirsuta) annual arable garden weed

Nigel Cattlin / Young plants of hairy bittercress (Cardamine hirsuta) a common garden weed on bare soil, Devon, England, UK, April

Nigel Cattlin / Annual meadow-grass (Poa annua) with tillers / shoots and flower - an annual garden and agriculture weed

Nigel Cattlin / Annual meadow-grass (Poa annua) with tillers / shoots and flower - an annual garden and agriculture weed

Nigel Cattlin / Annual meadow-grass (Poa annua) with tillers and flower bud - a prostrate annual garden and agriculture weed

Nigel Cattlin / Herb robert (Geranium robertianum) seedling garden weed with cotyledons and first true leaf just developing

Nigel Cattlin / Sicklepod / Wild senna (Cassia tora) broad-leaved weed plant in flower and seedpod, North Carolina, USA, October

Nigel Cattlin / Purple morning glory (Ipomoea purpurea) flowering, a broad leaved weed, North Carolina, USA, October

Nigel Cattlin / Onion couch / False oat-grass (Arrhenatherum elatius) arable grass weed in a wheat crop coming into ear

Nigel Cattlin / Redshank (Polygonum maculosa) weed plants in young sugar beet crop on dark fen soil

Nigel Cattlin / Charlock (Sinapis arvensis) young plant in the field against a soil background

Nigel Cattlin / Redshank (Persicaria maculosa) seedlings with other weeds in seedling sugar beet on Cambridgeshire Fen soil

Nigel Cattlin / Scentless mayweed (Triplerospermum inodorum) profusely flowering chamomile or mayweed like plant and flower beetle (Meligethes aeneus) , Berkshire, England, UK, July

Nigel Cattlin / Scentless mayweed (Triplerospermum inodorum) profusely flowering chamomile or mayweed like plant, Berkshire, England, UK, July

Nigel Cattlin / Scentless mayweed (Triplerospermum inodorum) profusely flowering chamomile or mayweed like plant, Berkshire, England, UK, July

Nigel Cattlin / Dandelion (Taraxacum officinale) plant rosette with a large number of yellow composite flowers, Berkshire, England, UK, May