Lilium bulbs are starchy and edible as root vegetables, although bulbs of some species may be very bitter. The non-bitter bulbs of L. lancifolium, L. pumilum, and especially L. brownii (Chinese: 百合 干; pinyin: bǎihé gān) and Lilium davidii var unicolor are grown on a large scale in China as a luxury or health food, and are most often sold in dry form for herb, the fresh form often appears with other vegetables. The dried bulbs are commonly used in the south to flavor soup. Lily flowers are also said to be efficacious in pulmonary affections, and to have tonic properties. Lily flowers and bulbs are eaten especially in the summer, for their perceived ability to reduce internal heat. They may be reconstituted and stir-fried, grated and used to thicken soup, or processed to extract starch. Their texture and taste draw comparisons with the potato, although the individual bulb scales are much smaller. There are also species which are meant to be suitable for culinary and/or herb uses. There are five traditional lily species whose bulbs are certified and classified as "vegetable and non-staple foodstuffs" on the National geographical indication product list of China.