The custom of eating fern leaves is typical of Asian cultures and can be found in South-east Asian countries such as Malaysia and the Philippines. All three of the Diplazium genus species are edible, but the first (Diplazium esculentum) is the most common and currently grown extensively, while the other two replace it in mid to high mountainous areas. Being able to tell them apart from the other species of the Athyriaceae is of prime importance, since only the tender fronds of the guomao is eaten, but all have rough furled fronds, so they are easy to mix up when harvested.
Indigenous mountain populations, who have greater opportunities of coming into contact with this plant, especially with Diplazium dilatatum and Diplazium muricatum, know it very well and eat it in various ways. They are becoming more and more popular and known as a wild herb, symbol of the culinary culture of the mountains.
It is important to remove the ptaquiloside before eating them. It is a fern toxin that, as has been scientifically proven, is a carcinogen and can cause cancer of the stomach. Unfortunately, the concentration of ptaquiloside is very high in the young fronds, but it is soluble in water and decomposes at high temperatures. Therefore, guomao is often eaten boiled, dressed with olive oil, prune juice or soy sauce.
Its high manganese content compared to other plants makes it useful for the formation of hemoglobin. Moreover, a high potassium content helps to control high blood pressure, but the potassium ions are also water soluble, therefore it is best not to boil it for more than three minutes.