Nelumbo nucifera Gaertn. (Nelumbonaceae)
Nelumbo nucifera subsp. lutea (Willd.) Borsh & Barthlott
Nelumbo nucifera var. lutea (Willd.) Kuntze
Nelumbo nucifera var. macrorhizomata Nakai
Nelumbo caspica (Fisch.) Schipcz
Nelumbo caspica (Fish)
Nelumbo komarovii (Grossh)
Nelumbo speciosa Willd.
Nelumbo speciosa var. alba F.M. Bailey
Nymphaea nelumbo L.
Lotus, Indian Lotus, Sacred Lotus, Bean of India, East Indian Lotus, Lotusroot, Oriental Lotus, Fève d’Egypte, Lotus Indien, Lotus Sacré, Indische Lotosblume, Indischer Lotus, Padma, Lotus-do-Egito, Flor-de-Lotus, Lótus, Lótus-indico, Lótus-sagrado, Loto sagrado, Rosa del Nilo, Indisk Lotus, Lian, Yeonkkot (GRIN 2016, see Lim 2015 for a full list).
N. nucifera is an aquatic flowering plant that is found throughout Asia (Iran to China, Japan and New Guinea) and northern Australia in both warm-temperate and tropical areas. Plants have also been naturalized in other parts of the world including Hawaii (GRIN 2016). It is interesting to note that members from the genus Nelumbo are believed to have once inhabited other parts of the world such as Greenland, Patagonia, Argentina, Alaska, as well as parts of Africa. These species or populations largely disappeared over time, and it is believed that remaining individuals which survived the quaternary ice age by seeking refuge at lower latitudes in Asia or North America led to current native distribution for Nelumbo (Fig 1). Furthermore, extensive ethnobotanical use of N. nucifera by humans for religion, food, medicine, etc is also believed to have increased the habitat range (Ya et al. 2014; Borsh and Barthlott, 1994; Fig 1).
Wetland habitats (up to 2.5 m deep) such as floodplains, ponds, lakes, pools, lagoons, marshes, swamps, etc.
The genus Nelumbo consists of only two species, N. nucifera and Nelumbo lutea Willd. Plants are aquatic, with peltate leaves (up to 75 cm in diameter) that emerge from an underwater rhizome. Flowers are solitary, either pink, pink-purple, white (N. nucifera) or pale yellow (N. lutea), being borne above the water surface. Flowers consist of 14-30 tepals, with numerous stamen (100 – 400) surrounding an obconical receptacle with (2)-10-30 carpels separately embedded within it (Fig. 2) (Hayes, Schneider & Carlquis 2000; Wiersema 1997).
Although the showy and attractive flowers of lotus species closely resemble water lilies (Nymphaea L.), they are not closely related (Ya et al. 2014) and can easily be differentiated from water lilies by their obconical receptacle as well as other features including the absence of a ‘v-shaped’ incision on leaves (for further information click here)
In the wild, differentiation between the two lotus species is quite easy, as N. lutea is found in parts of North America, Caribbean and Mesoamerica, while N. nucifera grows in parts of Asia and Australia (see above). According Wiersema (1997), ornamental cultivars for Sacred Lotus (N. nucifera) have sporadically naturalized in southeastern parts of the United States. Although flower color can also be used to differentiate between species, hybrids made from both species have been developed, making color a less reliable identifier amongst ornamental cultivars (Ya et al. 2014).
(1) Food – Sacred lotus is cultivated for food in parts of Asia including China, Japan, Taiwan and South Korea. It is believed that cultivation has been underway since at least 1200 BC and 500 AD in China and Japan respectively. In China, rhizomes and seeds have been eaten for at least 3,000 years which has led to hundreds of cultivars which can be divided into three categories: (i) Lotus for fruit or seed (Lian-zi, Lian-mi); (ii) Lotus for flowers (Lian hua, Her ha); and (iii) Lotus for rhizomes (Lian-ngau, Ou-lian). Similarly, in Japan cultivars from the above categories are grown, but are classified further as ‘Japanese’ or ‘Chinese’ (Nguyen & Hicks, 2001). All parts of the plant are edible (leaves, flowers, rhizome, root, seed, and stems), for instance leaves, stems and rhizomes can be pickled, fried, boiled, or eaten raw. Starches from Rhizomes can also be extracted and used as a food additive or to make starchy beverages. Seeds can be eaten raw, boiled, or roasted (to make a coffee substitute or popped like popcorn). In Korea, blossoms have been used to make a lotus liquor, while in China and Indo-China stamens from the flowers are used to flavor tea (See Lim 2015 for full review).
(2) Medicine – Traditionally, all parts of N. nucifera have been used as medicine. In Ayurveda, stems are used to treat water retention, urinary complaints, parasitic infections, or skin and neurological conditions. Flowers have been employed to treat gastrointestinal issues, fever, or cholera, while leaves are used to stop an individual from bleeding both internally and externally. In Asia, seeds and fruits are used to treat a wide spectrum of ailments including digestive complaints, inflammation, cancer, fever, leprosy, bleeding, nervousness, insomnia, etc (Mehta et al. 2013)
(3) Decoration – Cultivation and breeding of specific lotus cultivars for decoration has been underway in China and Japan for over 2,500 and 300 years respectively. Since then, it is estimated that approximately 2,000 cultivars have emerged around the world from breeding N. nucifera and/or N. lutea (Tian et al. 2014). In order to keep track of these efforts, the “International Nelumbo Database” was developed in 1998 (For further information see http://www.nelumbolotus.com/).
(4) Mind-Altering Substance – Flowers as well as other parts of the plant can be made into a tea, macerated in wine, or smoked to produce a mild sedative effect. In recent years, N. nucifera has been used alongside other psychoactive plants or substances as an ingredient in ‘herbal smoking blends’ (i.e. spice) which are smoked to produce a cannabis-like effect (O’Mahoney Carey 2010). Although there is some evidence to suggest that ingestion of N. nucifera may facilitate anti-depressant, sedative or analgesic effects, underlying mechanisms for its use as a mind-altering substance are still unclear (Kumarihamy et al. 2015).
N. nucifera is the national flower of India and Vietnam and is considered one of the ten principal traditional Chinese flowers (Tian et al. 2014). With a symbolic history of over 5,000 years, the sacred lotus has accumulated different meanings within different cultures and religions. Unfortunately, due to the resemblance between N. nucifera with species of water lily, it is challenging at times to properly identify which plant species is being referred to as ‘Lotus’. Other times, it is quite easy to tell, particularly when descriptions or artistic works were derived from cultures located outside of N. nucifera’s native habitat. For example, a species of water-lily (Nymphaea caerulea Sav) known as ‘blue lotus’ or ‘Egyptian blue lotus’ is commonly depicted in ancient Egyptian art, culture and spirituality, however given N. nucifera’s native range and flower color, it is very easy to eliminate this species as a candidate.
Regardless of botanical nomenclature, lotus plants have served as important cultural symbols and metaphors both past and present. For instance, lotus is mentioned in the Greek mythology of Homer’s “The Odyssey” when Odysseus encounters a group of individuals known as “the lotus eaters”. While visiting, Odysseus and his warriors are encouraged to consume lotus plants, as the narcotic and addictive effects will enable them to forget their home, friends, and family as well as yield the feeling of never wanting to leave (Carstairs 1969). Interestingly, the term ‘lotusland’ has been used to describe cities located on the Westcoast of North America and is believed to stem from the story of the lotus eaters. For example, Allan Fotheringham, a prominent Canadian journalist, used this term to depict parts of British Columbia, Canada in order to describe the new-age culture, laid-back philosophy, and availability of drugs amongst inhabitants in the 1960s. It is believed that the term ‘lotusland’ has been used since the mid-1800s, as such Merriam Webster Dictionary has included a definition for ‘lotusland’ where by it is a term used to describe “a place inducing contentment especially through offering an idyllic living situation” or “a state or an ideal marked contentment often achieved through self-indulgence”.
In Hindu mythology, the lotus serves as a symbol of creation as it is believed that Brahma, creator and God of the universe, sprang from a lotus blossom. In Buddhism the lotus represents enlightenment, with the name lotus being used to describe one of the most influential texts in Buddhism also known as the “Lotus Sūtra” (Ward 1952).
Physical characteristics of the Lotus have also served as metaphors in spiritual and religious teachings. For example, the ability of a lotus to grow out of murky waters in nature to produce a clean white colored blossom has served as a representation for purity in Hinduism. The muddy water represents impurities or sins and signifies that the lotus can still emerge detached and untouched despite being rooted to a muddy world. A similar concept is seen in Buddhism through the ability of a lotus to float above muddy waters (free from attachment and desire), which in turn represents purity of the body, speech and mind. The lotus also denotes creation out of water. Similar to Brahma, other Hindu gods are pictured sitting on or holding a lotus. For instance, the Hindu goddess of wealth, fortune, and prosperity otherwise known as Lakshmi is often pictured as standing or sitting on a lotus (Ward 1952). Buddhists also associate the emergence of lotuses from water with the announcement of Buddha’s birth, as it is believed that he walked seven steps forward to find a lotus springing up for each footstep. Buddha is also often depicted sitting or holding a lotus (Ward 1952).
In addition to creation, other meanings have been associated with the physiology of lotus, for example, its ability to bear fruit and flowers at the same time demonstrates its ability to transcend time, while also representing the past, present, and future. Furthermore its ability to avoid being sullied by water signifies perfection and beauty (Ward 1952; Lehner & Lehner, 1985).
Current Importance to Society
In addition to being an important cultural/spiritual symbol to many parts of the world, lotus is an important economic crop in parts of Asia. For example, it is estimated that 3 million tons of fresh rhizome and 15,000 tons of dry seed are harvested annually in China (Zhao, 1999).
While a wide spectrum of cultivars for N. nucifera are grown commercially as food, ornamental or medicine in Asia, there is growing concern that wild populations are become threatened as a result of the growing aquaculture industry, global warming and habitat fragmentation (Han et al. 2006; Yang et al. 2013). N. nucifera can reproduce by seed (sexually) or vegetatively by its rhizome (asexually). Although flowers are insect pollinated, which in turn can promote genetic diversity within a given population, research found clonal diversity to be high (low genetic diversity) within selected populations. Given a high level of genetic differentiation has been found to exist between populations, conservation efforts should focus on in situ as well as ex situ conservation by transplanting or collecting seed from a few individuals from each population (Han et al. 2006; Yang et al. 2013).