''Nelumbo'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of
aquatic plants with large, showy
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s. Members are commonly called lotus, though the name is also applied to
various other plants and plant groups, including the unrelated genus ''
Lotus''. Members outwardly resemble those in the family
Nymphaeaceae ("water lilies"), but ''Nelumbo'' is actually very distant to that family.
There are only two known living species of lotus; ''
Nelumbo nucifera
''Nelumbo nucifera'', also known as sacred lotus, Laxmi lotus, Indian lotus, or simply lotus, is one of two extant taxon, extant species of aquatic plant in the Family (Biology), family Nelumbonaceae. It is sometimes colloquially called a water ...
'' is native to
East Asia
East Asia is the eastern region of Asia, which is defined in both Geography, geographical and culture, ethno-cultural terms. The modern State (polity), states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. ...
,
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical
Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth descr ...
,
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...
and probably
Australia, and is better-known. It is commonly cultivated; it is eaten and used in
traditional Chinese medicine
Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of acti ...
.
The other lotus is ''
Nelumbo lutea
''Nelumbo lutea'' is a species of flowering plant in the family Nelumbonaceae. Common names include American lotus, yellow lotus, water-chinquapin, and volée. It is native to North America. The botanical name ''Nelumbo lutea'' Willd. is the ...
'', which is
native
Native may refer to:
People
* Jus soli, citizenship by right of birth
* Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory
** Native Americans (disambiguation)
In arts and entert ...
to
North America and the
Caribbean. Horticultural hybrids have been produced between these two
allopatric species.
Description
Ultrahydrophobicity
![Nelumbo nucifera (Indian Lotus)- water drops W IMG 8657](https://upload.wikimedia.org/wikipedia/commons/1/16/Nelumbo_nucifera_%28Indian_Lotus%29-_water_drops_W_IMG_8657.jpg)
The
leaves of ''Nelumbo'' are highly water-repellent (i.e. they exhibit
ultrahydrophobicity
Ultrahydrophobic (or superhydrophobic) surfaces are highly hydrophobic, i.e., extremely difficult to wet. The contact angles of a water droplet on an ultrahydrophobic material exceed 150°. This is also referred to as the lotus effect, after the ...
) and have given the name to what is called the
lotus effect
The lotus effect refers to self-cleaning properties that are a result of ultrahydrophobicity as exhibited by the leaves of ''Nelumbo'', the lotus flower. Dirt particles are picked up by water droplets due to the micro- and nanoscopic architec ...
. Ultrahydrophobicity involves two criteria: a very high water contact angle between the droplet of water and the leaf surface, and a very low roll-off angle.
This means that the water must contact the leaf surface at exactly one, minuscule point, and any manipulation of the leaf by changing its angle will result in the water droplet rolling off of the leaf.
Ultrahydrophobicity is conferred by the usually dense layer of papillae on the surface of the ''Nelumbo'' leaves, and the small, robust, waxy tubules that protrude off each papilla.
This helps reduce the area of contact between the water droplet and the leaf.
Ultrahydrophobicity is said to confer a very important
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
ary advantage. As an aquatic plant with leaves that rest on the water's surface, the genus ''Nelumbo'' is characterized by its concentration of
stomata on the upper
epidermis of its leaves, unlike most other plants which concentrate their stomata on the lower
epidermis, underneath the leaf.
The collection of water on the upper epidermis, whether that be by rain, mist, or the nearby disturbance of water, is very detrimental to the leaf's ability to perform gas exchange through its stomata. Thus, ''Nelumbo's'' ultrahydrophobicity allows the water droplets to accumulate together very quickly, and then roll off of the leaf very easily at the slightest disturbance of the leaf, a process which allows its stomata to function normally without restriction due to blockage by water droplets.
Thermoregulation
A unique property of the genus ''Nelumbo'' is that it can
generate heat,
which it does by using the alternative oxidase pathway (AOX).
This pathway involves a different, alternative exchange of
electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary particles because they have no ...
s from the usual pathway that electrons follow when generating energy in
mitochondria, known as the AOX, or alternative oxidase pathway.
The typical pathway in plant mitochondria involves
cytochrome
Cytochromes are redox-active proteins containing a heme, with a central Fe atom at its core, as a cofactor. They are involved in electron transport chain and redox catalysis. They are classified according to the type of heme and its mode of bi ...
complexes. The pathway used to generate heat in ''Nelumbo'' involves
cyanide
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.
In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
-resistant alternative oxidase, which is a different electron acceptor than the usual cytochrome complexes.
The plant also reduces
ubiquitin
Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Fo ...
concentrations while in
thermogenesis
Thermogenesis is the process of heat production in organisms. It occurs in all warm-blooded animals, and also in a few species of thermogenic plants such as the Eastern skunk cabbage, the Voodoo lily ('' Sauromatum venosum''), and the giant w ...
, which allows the AOX in the plant to function without degradation
Thermogenesis is restricted to the
receptacle,
stamen, and
petals of the flower, but each of these parts produce heat independently without relying on the heat production in other parts of the flower.
There are several theories about the function of thermogenesis, especially in an aquatic genus such as ''Nelumbo''. The most common theory posits that thermogenesis in flowers attracts
pollinators, for a variety of reasons. Heated flowers may attract insect pollinators. As the pollinators warm themselves while resting inside the flower, they deposit and pick up
pollen onto and from the flower.
The thermogenic environment might also be conducive to pollinator
mating
In biology, mating is the pairing of either opposite- sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. ''Copulation'' is the union of the sex organs of two sexually reprod ...
; pollinators may require a certain temperature for reproduction. By providing an ideal thermogenic environment, the flower is pollinated by mating pollinators.
Others theorize that heat production facilitates the release of
volatile compounds into the air to attract pollinators flying over water, or that the heat is recognizable in the dark by thermo-sensitive pollinators. None have been conclusively proven to be more plausible than the others.
After
anthesis
Anthesis is the period during which a flower is fully open and functional. It may also refer to the onset of that period.
The onset of anthesis is spectacular in some species. In ''Banksia'' species, for example, anthesis involves the extension ...
, the receptacle of the lotus transitions from a primarily thermogenic to a
photosynthetic structure, as seen in the rapid and dramatic increase in
photosystem
Photosystems are functional and structural units of protein complexes involved in photosynthesis. Together they carry out the primary photochemistry of photosynthesis: the absorption of light and the transfer of energy and electrons. Photosystems ...
s, photosynthetically involved pigments, electron transport rates, and the presence of
13C in the receptacle and petals, all of which assist in increasing photosynthesis rates.
After this transition, all thermogenesis in the flower is lost. Pollinators do not need to be attracted once the
ovary is fertilized, and thus the receptacle's resources are better used when it is photosynthesizing to produce
carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...
s that can increase plant biomass or fruit mass.
Other plants utilize thermoregulation in their life cycles. Among these is the
eastern skunk cabbage
''Symplocarpus foetidus'', commonly known as skunk cabbage or eastern skunk cabbage (also swamp cabbage, clumpfoot cabbage, or meadow cabbage, foetid pothos or polecat weed), is a low growing plant that grows in wetlands and moist hill slopes of ...
, which heats itself to melt any ice above it, and push through the ground in early spring,. Also, the
elephant yam, which heats its flowers to attract pollinators. In addition, the
carrion flower
Carrion flowers, also known as corpse flowers or stinking flowers, are mimetic flowers that emit an odor that smells like rotting flesh. Apart from the scent, carrion flowers often display additional characteristics that contribute to the mimes ...
, which heats itself to disperse water vapor through the air, carrying its scent further, thus attracting more pollinators.
Similar species
The leaves of ''Nelumbo'' can be distinguished from those of genera in the family
Nymphaeaceae as they are
peltate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...
, that is they have fully circular leaves. ''
Nymphaea'', on the other hand, has a single characteristic notch from the edge in to the center of the lily pad. The
seedpod
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnify ...
of ''Nelumbo'' is very distinctive.
Taxonomy
Taxonomic history
The
Cronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) ...
of 1981 recognizes the family
Nelumbonaceae
Nelumbonaceae is a family of aquatic flowering plants. ''Nelumbo'' is the sole extant genus, containing ''Nelumbo lutea'', native to North America, and ''Nelumbo nucifera'', widespread in Asia. At least four other genera, ''Nelumbites'', ''Exne ...
but places it in the water lily order
Nymphaeales
The Nymphaeales are an order of flowering plants, consisting of three families of aquatic plants, the Hydatellaceae, the Cabombaceae, and the Nymphaeaceae (water lilies). It is one of the three orders of basal angiosperms, an early-diverging ...
. The
Dahlgren system
One of the modern systems of plant taxonomy, the Dahlgren system was published by monocot specialist Rolf Dahlgren in 1975 and revised in 1977, and 1980. However, he is best known for his two treatises on monocotyledons in 1982 and revised in 19 ...
of 1985 and
Thorne system A system of plant taxonomy, the Thorne system of plant classification was devised by the American botanist Robert F. Thorne (1920–2015) in 1968, and he continued to issue revisions over many years (1968–2007).
Some versions of the system are ...
of 1992 both recognize the family and place it in its own order, Nelumbonales. The
United States Department of Agriculture
The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
still classifies the lotus family within the water lily order.
There is residual disagreement over which family the genus should be placed in. Traditional classification systems recognized ''Nelumbo'' as part of the Nymphaeaceae, but traditional taxonomists were likely misled by
convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
associated with an evolutionary shift from a terrestrial to an aquatic lifestyle. In the older classification systems it was recognized under the order Nymphaeales or Nelumbonales.
Modern classification
''Nelumbo'' is currently recognized as the
only living genus in Nelumbonaceae, one of several distinctive families in the
eudicot order of the
Proteales. Its closest living relatives, the (
Proteaceae and
Platanaceae
Platanaceae, the "plane-tree family", is a family of flowering plants in the order Proteales. The family consists of only a single extant genus ''Platanus'', with eight known species. The plants are tall trees, native to temperate and subtropic ...
), are shrubs or trees.
The
APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was published ...
of 2016 recognizes Nelumbonaceae as a distinct family and places it in the order Proteales in the eudicot
clade, as do the earlier
APG III APG is an abbreviation with several different meanings:
* Aberdeen Proving Ground, a United States Army installation in Aberdeen, Maryland, also
** Phillips Army Airfield, the airfield of the above, from its IATA airport code
* Aboriginal Provisiona ...
and
APG II system
The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Gr ...
s.
Phylogeny
There are several fossil species known from
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...
,
Paleogene and
Neogene aged strata throughout
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...
and
North America. Despite the ancient origins of this genus and the wide geographic separation of the two extant species (''N. nucifera'' and ''N. lutea''), phylogenetic evidence indicates that they diverged rather recently, during the early
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
(about 2 million years ago).
Species
Extant species
*''
Nelumbo lutea
''Nelumbo lutea'' is a species of flowering plant in the family Nelumbonaceae. Common names include American lotus, yellow lotus, water-chinquapin, and volée. It is native to North America. The botanical name ''Nelumbo lutea'' Willd. is the ...
''
Willd.
Carl Ludwig Willdenow (22 August 1765 – 10 July 1812) was a German botanist, pharmacist, and plant taxonomist. He is considered one of the founders of phytogeography, the study of the geographic distribution of plants. Willdenow was al ...
– American lotus (
Eastern United States
The Eastern United States, commonly referred to as the American East, Eastern America, or simply the East, is the region of the United States to the east of the Mississippi River. In some cases the term may refer to a smaller area or the East C ...
,
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
,
Greater Antilles
The Greater Antilles ( es, Grandes Antillas or Antillas Mayores; french: Grandes Antilles; ht, Gwo Zantiy; jam, Grieta hAntiliiz) is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, Jamaica, a ...
,
Honduras)
*''
Nelumbo nucifera
''Nelumbo nucifera'', also known as sacred lotus, Laxmi lotus, Indian lotus, or simply lotus, is one of two extant taxon, extant species of aquatic plant in the Family (Biology), family Nelumbonaceae. It is sometimes colloquially called a water ...
''
Gaertn.
Joseph Gaertner (12 March 1732 – 14 July 1791) was a German botanist, best known for his work on seeds, ''De Fructibus et Seminibus Plantarum'' (1788-1792).
Biography
He was born in Calw, and studied in Göttingen under Albrecht von Haller ...
– sacred or Indian lotus, also known as the Rose of India and the sacred water lily of
Hinduism
Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...
and
Buddhism
Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religions, Indian religion or Indian philosophy#Buddhist philosophy, philosophical tradition based on Pre-sectarian Buddhism, teachings attributed to the Buddha. ...
.
It is the
national flower of
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
and
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
. Its roots and
seeds are also used widely in cooking in East Asia, South Asia and Southeast Asia.
Fossil species
*†''
Nelumbo aureavallis''
Hickey
A hickey, hickie or love bite in British English, is a bruise or bruise-like mark caused by kissing or sucking skin, usually on the neck, arm, or earlobe. While biting may be part of giving a hickey, sucking is sufficient to burst small superfic ...
–
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
(
North Dakota
North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, So ...
), described from leaves found in the Golden Valley Formation in North Dakota, USA.
*†''
Nelumbo changchangensis'' Eocene, (
Hainan Island
Hainan (, ; ) is the smallest and southernmost province of the People's Republic of China (PRC), consisting of various islands in the South China Sea. , the largest and most populous island in China,The island of Taiwan, which is slightly ...
, China), described from several fossils of leaves, seedpods, and rhizomes from the Eocene-aged strata in the Changchang Basin, of Hainan Island.
*†''
Nelumbo minima''
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58[Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...](_blank)
), described from leaves and seedpods that suggest a very small plant. Originally described as a member of the genus ''
Nelumbites'', as "''Nelumbites minimus''."
*†''
Nelumbo nipponica''
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
-
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
, fossil leaves are known from Eocene-aged strata in
Japan, and Miocene-aged strata in
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
.
*†''
Nelumbo orientalis''
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...
(Japan), one of the oldest known species, fossils are found in Cretaceous-aged strata of Japan.
*†''
Nelumbo protolutea'' Eocene (
Mississippi
Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
), fossils of leaves strongly suggest a plant similar in form to the American lotus.
Etymology
The genus name is derived from si, නෙළුම් ''neḷum'', the name for ''Nelumbo nucifera''.
Uses
The entire plant can be eaten either raw or cooked. The underwater portion is high in
starch. The fleshy parts can be dug from the mud and baked or boiled. The young leaves can be boiled. The seeds are palatable and can be eaten raw or dried and ground into flour. The stem fibers are also used to make
lotus silk
Lotus silk ( my, or my, , ) is a type of textile produced using delicate lotus stem fibers. The fabric first originated in Myanmar (Burma), and is now also woven by smaller-scale cottage industries in Vietnam. Due to the complexity and labor- ...
.
Weaving success: Manipur woman seeks to employ more locals in her lotus silk venture
/ref>
Culture
The sacred lotus, ''N. nucifera'', is sacred in both Hinduism
Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...
and Buddhism
Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religions, Indian religion or Indian philosophy#Buddhist philosophy, philosophical tradition based on Pre-sectarian Buddhism, teachings attributed to the Buddha. ...
.[ It is the ]floral emblem
In a number of countries, plants have been chosen as symbols to represent specific geographic areas. Some countries have a country-wide floral emblem; others in addition have symbols representing subdivisions. Different processes have been used to ...
of both India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
and Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
.
References
External links
links at CSDL
{{Taxonbar, from=Q207427
Eudicot genera