Consumers are being urged to question where wild plants in products from chocolate to cosmetics have come from as part of efforts to make them more sustainable.
Herbal remedies, food, drink, cosmetics and even furniture can come from wild harvested plants, but industry and consumers are paying "far too little attention" about whether they are being traded responsibly, campaigners said.
A report highlighting the issue by wildlife trade monitoring network Traffic says that of the 30,000 plant species with documented medicinal or aromatic uses, around 3,000 are found in international trade.
An estimated 60% to 90% of plants traded globally are harvested from the wild, often with little consideration given to ensure sustainable supplies, Traffic warned.
The global trade in medicinal plants alone has grown threefold since 1999 to be worth £2.3 billion in 2015, although that is likely to be an underestimate.
But only 7% of the world's plants which have medicinal or aromatic properties have been assessed to see if they are at risk of extinction, and a fifth of those that have are under threat, the report said.
Harvesting too much of a plant and damaging processes such as using heavy machinery to collect wild liquorice root are significant reasons for wild plant species being in decline, the report warned.
But sustainable harvesting and trade could help manage habitats well for other wildlife and provide incomes to local people.
Anastasiya Timoshyna, from Traffic - who co-authored the report, said: "Millions of people rely on wild plant collection both for their healthcare and for their livelihoods, from rural rosehip harvesters in Serbia to baobab fruit collectors in Zimbabwe and the wide benefits of this harvesting are reaped by consumers across the world.
"But the industry utilising wild plant ingredients and consumers are paying far too little attention to ensuring plants are being traded responsibly.
"It's in everyone's interests to ensure that their use of wild plants is responsible in terms of ecological and social sustainability, so we all need to learn about the origin of the products we are using."
Consumers are being urged to look out for the FairWild logo, which ensures sustainable harvesting and trade in wild plants, and ask the brands they buy if the plant products in them have been sourced fairly and sustainably.
"Companies often market their products as being 'naturally sourced' or 'wild' with little interpretation of what that actually entails: it's time for consumer pressure to ensure it really means they have been sustainably or ethically traded - if in doubt look for the FairWild logo on the packaging or ask why it doesn't appear," she said.
The report is being published to mark FairWild week which aims to support efforts to make sure wild plants are sustainably sourced.