With the Latin flora name Ottelia acuminata, the seaweeds (locally called "Hai Cai Hua") can be seen flourishing in summer in most freshwater lakes of Dali, Lijiang and Kunming.

As a kind of perennial herbaceous plant, it grows in unpolluted waters, and its florescence can last from May to October. Most part of the plant can be used in the kitchen; and especially in Dali, it's a very rare delicacy.

Haicai or Edible Seaweed is algae that can be eaten or are used in the preparation of food. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. Seaweeds are used extensively as food in coastal cuisines around the world. Seaweed has been a part of diets in China, Japan, and Korea since prehistoric times. Seaweed is also consumed in many traditional European societies, especially in northern and western Ireland, Iceland and western Norway.

Seaweed is also eaten in some parts of the Atlantic coast of France as well as Nova Scotia and Newfoundland. Most edible seaweeds are marine algae as most freshwater algae are toxic. While marine algae are not toxic, some do contain acids that irritate the digestion canal, while some others can have a laxative effect. Japan consumes no fewer than 7 types of seaweed identified by name, and the general term for seaweed is used primarily for science and not in menus.

Haicai is a kind of green algae growing under water. They grow and float on the surface of Erhai Lake. The seaweed is one of the most powerful foods available, providing an easy, practical and delicious way to fend off the damaging effects of stress, free radicals, environmental pollutants and radiation. Nutrient dense and packed with an array of unique substances, seaweed is an effective and healthy way to improve mineral levels, boost immunity and detoxify the body. This is probably why it has been used for so long in many Asian cultures. The minerals contained in seaweed are absolutely essential for every cellular process in the body.