Botanical name: Nelumbo nucifera
Common name: Lotus seed
Part used in Chinese medicine: seed
Major Chinese medicine actions:
Tonifies Spleen, stops diarrhea, tonifies Kidneys, stabilizes essence,
nourishes Heart, calms spirit
Photo Credits: (top to bottom)
Lian Zi Photo 1: Nelumbo nucifera; author Shin; permission under Creative Commons
Photo 2: Nelumbo nucifera; author Ram-Man; permission under Creative Commons
Photo 3: Nelumbo nucifera; 08/2005; author Tobixen, Sjschen; permission under GFDL
Photo 4: Nelumbo nucifera; 10/2007; author Jbbrillo; permission under GFDL
The lotus is rich with symbolism in Chinese culture, thanks largely to the influence of Buddhism. It is one of the eight Buddhist precious things and in that tradition, the fruit, flower and stalk represent the past, present and future. The symbolism of the lotus includes purity, as the lotus grows out of the muddy mire, yet the flower is beautiful and perfect.
Nelumbo nucifera is native to western Asia from Iran eastwards to China, Japan and Australia. It is an aquatic perennial, found in large lakes, now widely cultivated around the world as both an ornamental in water gardens and a food and medicinal plant.
Researchers report that the lotus has the remarkable ability to regulate the temperature of its flowers within a narrow range, just as humans and other warm blooded animals do. Physiologists at the University of Adelaide in Australia found that lotus flowers blooming in the Adelaide Botanic Gardens maintained a temperature of 86 to 95 degrees F, even when the air temperature dropped to 50 degrees. They suspect the flowers may be staying warm for the benefit of their insect pollinators. The study was published in the journal “Nature” and it notes that there are very few other species with this temperature regulation function.
Growing and Propagation
The roots of Nelumbo nucifera grow from the mud of lakes, ponds and river bottoms, while the leaves float on top of the water surface. The flowers bloom on thick stems rising from several inches above the water to 5 feet, but have been found to grow as high as 16 feet. The plant is quite breathtaking, with leaves as large as 2 feet in diameter, and showy, fragrant flowers up to 7 inches in diameter. There are several different cultivars with flower colors ranging from white to yellow to light pink, blooming in late spring to mid summer.
The lotus requires rich loamy soil and grows in water up to 8 feet deep. In cooler climates, it should be grown in shallower water, though not less than 1 foot deep. This allows the water to warm up more quickly and allow for a good growing season and development of flowers. The plant requires a minimum of a 5-month growing season each year, and during this time does best with temperatures between 73 to 80 degrees F. The plant is hardy to -15 degrees F, to USDA zone 5, and does best in full sun.
The plants are easy to grow when in the proper conditions, and in warm water can grow very quickly. Once plants are established they will not transplant well, so should be planted in a permanent location as soon as possible. Once established though, they can become invasive and take over a large expanse of water.
The plant can be propagated by seed or rhizome. Seeds can be collected from plants where pods are allowed to dry on the plant. If seeds are well preserved, they may be viable for many years. One of the oldest seeds to germinate into a viable plant was an approximately 1,300-year-old lotus fruit, recovered from a dry lakebed in northeastern China. Before planting seeds, they should be filed across the middle, then soaked in warm water. The water should be changed twice a day for about 3-4 weeks until it germinates. They can then be planted in pots submerged in water, increasing the depth of the water as the plant grows. Plants can also be divided in the spring, though they often resent this disturbance. They will propagate themselves by rhizome.
Harvesting and Preparation
The leaves of the lotus (He Ye), lotus seed (Lian Zi), lotus flower stamens (Lian Xin, and newly sprouted shoots (Lian Zi Xin) are all used in Chinese medicine. Lotus seeds are commonly used in Asian cooking as well as in Chinese medicine. There are 2 main types of dried lotus seeds. One is reddish or brown color and is harvested in late fall or early winter when the seed head of the lotus is ripe or nearly ripe. The fruit is broken in half and the outer coating and bright green colored germ are removed in order to reduce the bitterness and tendency to cause nausea and vomiting.
The second is sometimes referred to as “white” lotus seed. This is the freshly collected fruit, harvested when the seed head is still fully green but with almost fully developed seeds. The lotus seeds left unbroken and the shell and membrane are removed. The bitter tasting germ of the seed is taken out right after harvesting using a hollow needle, though some may still remain in the seed due to production oversight. This Lian Zi is usually preferred for both medicinal and cooking use.
Dried lotus seeds past their prime oxidize to a yellow brown color. A light color is not a reliable indicator of freshness though, since sellers of dried lotus seeds sometimes bleach their products with hydrogen peroxide, sodium hydroxide, or other more toxic chemicals.