To Cornish shoppers, it will look like ordinary curly kale, but for the next two months it will be among the most eco-friendly vegetable produce in Britain.
Alongside cabbages, potatoes, broccoli and strawberries grown in Cornwall, the kale will be appearing on the shelves of Asda stores in the county and neighbouring Devon without first having made a 280-mile round trip to a distribution depot in Bristol.
The initiative - part of a trial which the Walmart-owned chain say will save 6,000 road miles a month - is the latest in a slew of projects announced by the main supermarkets to improve their environmental credentials.
From methane-powered lorries to "sun tubes" reflecting natural daylight into stores, the big four - Tesco, Sainsbury's, Asda and Morrisons - have opened a new "green" front in the battle for dominance of Britain's £90bn supermarket sector.
Retail analysts say that convincing consumers of their eco-friendliness has become the key priority for the main chains amid pressure from the Government and campaign groups.
The amount of C02 generated by road and air "food miles" rose by 6 per cent to 18 million tons in 2004, according to figures published last month. Food transport now accounts for 25 per cent of all lorry mileage in the UK.
The use of air freight by supermarkets and restaurants also nearly trebled in the 12 years to 2004, prompting the Environment Secretary, David Miliband, to demand that the big four should reduce their "environmental footprint".
Richard Clarke, of food retail magazine, The Grocer, said: "The environment is the single most important issue that is occupying the minds of the big supermarkets now. We have all read about how much they are responsible for a lot of the waste we produce and they know the way they are perceived by consumers is everything.
"But the hard reality is they not just doing it out of the goodness of their hearts. If they can reduce their escalating energy bills or fuel costs by green measures then that is simply good business sense."
Tesco and Asda have between them pledged to spend £200m on environmental measures, including the use of wind turbines, solar panels and biomass boilers. Asda has pledged that all its stores will be "zero waste" by 2010.
The chains say much can be achieved by small measures such as the Cornish scheme, which will allow three farms to pool resources and distribute goods directly to Asda stores in Falmouth, St Austell, Bodmin and Plymouth.
Chris Brown, Asda's head of ethical sourcing, said: "Rather than send it up the motorway, our farmers in Cornwall will deliver it direct to their local stores. That way we can ensure our fruit and veg is as fresh as possible and we'll minimise the impact on the environment."
The supermarket said the scheme, which is being trialled for two months, would cut vehicle carbon emissions by 21 tons a year and would save a further three million road miles annually if it was extended across Britain.
But environmentalists claim that the supermarket schemes often amount to "tokenism" designed to assuage the guilt of consumers.
Tesco was accused of a "greenwash" this month when it said it would encourage customers to cut their use of carrier bags by offering one point on their loyalty cards (worth 1p) for every bag they the reuse.
Friends of the Earth said that even if the chain met its target of reducing the number of bags by a quarter, it will still be handing out three billion of its new "degradable" bags each year, which are unlikely to break down in landfill sites because of the lack of direct sunlight.
The supermarket chain rejected the claims, saying it was opposed to charging for bags and insisting the scheme would cost it more that it would save.
How green is your supermarket?
TRANSPORT: Reduced the miles travelled by its suppliers to its depots by 23 per cent since 2004 and cut fuel use by 14 per cent. Is trialing a methane-powered lorry
ENERGY USE: Spending £100m to introduce measures including wind turbines, geothermal energy and a gasification plant which uses food waste to generate power
PACKAGING: Hands out four billion carrier bags a year, more than Sainsbury's and Asda combined. Pledges 25 per cent reduction by 2007 and will swap to "degradable" bags
ECO-CONTENT: Pledges to drop endangered fish species. Brings in less than three per cent of imports by air. Is considering joining sustainable palm oil initiative
TRANSPORT: Increasing the use of trains to transport non-perishable goods. Piloting a scheme for growers to deliver produce direct to stores
ENERGY USE: Has pledged that all its stores will be "zero waste" by 2010, including the use of biomass boilers to burn waste to produce heat and refrigeration
PACKAGING: Gives out 1.8 billion bags a year. This week starts a "bag for life" scheme, costing customers 5p per bag with 1p going to a breast cancer charity
ECO-CONTENT: Has pledged to stock only wild-caught fish from sustainable fisheries. Recently joined scheme to use only sustainably grown palm oil
TRANSPORT: Has reduced the number of road "food miles" by five per cent in the past 12 months and has pledged to move more goods by rail
ENERGY USE: Has the lowest CO2 emissions in the sector and has pledged to reduce amount of waste sent to landfill by five per cent by 2010
PACKAGING: Gives out 1.6 billion bags a year. Has pledged to cut bag use by five per cent this year and sells 120,000 "permanent" bags a week
ECO-CONTENT: No longer stocks endangered fish species and has joined sustainable palm oil scheme
TRANSPORT: No information on food miles, but says it has introduced fuel-efficiency measures for its lorry fleet
ENERGY USE: Pledged to reducing in-store CO2 emissions from current level of 764,000 tons a year
PACKAGING: Gives out 1.3 billion bags a year. Described a reward scheme to encourage reuse as being "of limited success"
ECO-CONTENT: Has pledged to drop endangered fish species but continues to use palm oil not certified as sustainable. Sells bio-ethanol fuel
TRANSPORT: A scheme operates in all stores to offer local produce, which is given its own display section
ENERGY USE: In-store emissions have increased by 17 per cent in the last year but the chain says this is because it has more stores. Relative emissions have dropped since 2004
PACKAGING: The first supermarket chain to offer a "bag for life" scheme. Gives out 260 million bags a year and recycles returned bags
ECO-CONTENT: Accounts for 10 per cent of the whole organic market. Does not stock endangered fish and has joined sustainable palm oil scheme