Pandanales, the pandans or screw-pines, is an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s placed in the

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

in the

Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disco ...

and

Angiosperm Phylogeny Web The Angiosperm Phylogeny Website (or APweb) is a website dedicated to research on angiosperm phylogeny and taxonomy. The site is hosted by the Missouri Botanical Garden website and maintained by researchers, Peter F. Stevens and Hilary M. Davis ...

systems A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and express ...

. Within the monocots Pandanales are grouped in the

lilioid monocots Lilioid monocots (lilioids, liliid monocots, petaloid monocots, petaloid lilioid monocots) is an informal name used for a grade (grouping of taxa with common characteristics) of five monocot orders (Petrosaviales, Dioscoreales, Pandanales, L ...

where they are in a

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

relationship with the

Dioscoreales The Dioscoreales are an order of monocotyledonous flowering plants in modern classification systems, such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. Within the monocots Dioscoreales are grouped in the lilioid monocots ...

. Historically the order has consisted of a number of different

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

in different systems but modern classification of the order is based primarily on

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

despite diverse

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

which previously placed many of the families in other groupings based on apparent similarity. Members of the order have a subtropical distribution and includes

trees In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are u ...

shrubs A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

, and

vines A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themselv ...

as well as

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

plants. The order consists of 5 families, 36 genera and about 1,610

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

Description

Pandanales are highly diverse including large

arboraceous A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposite to herbaceous plants that die back to the ground until s ...

plants of

tropical rainforests Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equator ...

and

coastal The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

areas, climbing

and

lianas A liana is a long- stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word ''liana'' does not refer to a ta ...

, as well as very small

achlorophyllous Myco-heterotrophy (from Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food fro ...

(mycoheterotrophic) and

saprophytic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi (f ...

forest floor The forest floor, also called detritus, duff and the O horizon, is one of the most distinctive features of a forest ecosystem. It mainly consists of shed vegetative parts, such as leaves, branches, bark, and stems, existing in various stage ...

species. This has made it difficult to reliably define

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

, but the loss of trimery distinguishes many of them from other lilioid monocots. The Pandanales order is distinctive with its highly variable and hardly definable floral morphology, especially the number of

stamens The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

and their structure as well as many other characteristics. In some of the members, different interpretations exist regarding the composition and organization of the reproductive structures. The order includes plants with traits that seem atypical when compared to other groups of

monocots Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of t ...

. A good example is the female reproductive organ and its position relative to other parts of the

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 ...

. Some of the species included in the families

Pandanaceae Pandanaceae is a family of flowering plants native to the tropics and subtropics of the Old World, from West Africa through the Pacific. It contains 982 known species in five genera, of which the type genus, ''Pandanus'', is the most important, wi ...

and

Stemonaceae The Stemonaceae are a family of monocotyledonous flowering plants placed in the order Pandanales. The family consists of four genera with ca 37 known species distributed in areas with seasonal climate across Southeast Asia and tropical Australia. ...

show flowers formed from only one

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

, while in the

Triuridaceae Triuridaceae are a family of tropical and subtropical flowering plants, including nine genera with a total of approximately 55 known species. All members lack chlorophyll and are mycoheterotrophic (obtain food by digesting intracellular fungi, o ...

, a family that lacks

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...

, the carpels are free from each other. In fact, the Triuridaceae possess the least "typical" flower morphology in the order.

Taxonomy

History

The components of the order ''sensu'' APG have been difficult to place consistently, and historically have been associated with a number of other groupings. The

Bentham & Hooker system A taxonomic system, the Bentham & Hooker system for seed plants, was published in Bentham and Hooker's ''Genera plantarum ad exemplaria imprimis in herbariis kewensibus servata definita'' in three volumes between 1862 and 1883. George Bentham (18 ...

(1883) had a similar order under the name Nudifloreae, incorporating: * Pandaneae *

Cyclanthaceae Cyclanthaceae is a family of flowering plants. Taxonomy Earlier systems, such as the Cronquist system and the Takhtajan system, placed it as the sole family in the order Cyclanthales. In the classification system of Dahlgren the Cyclanthaceae w ...

Typhaceae The Typhaceae () are a family of flowering plants, sometimes called the cattail family. The botanical name for the family has been recognized by most taxonomists. Description Members can be recognized as large marsh herbs with alternate two-rank ...

Aroideae Aroideae is a subfamily of flowering plants in the family Araceae. It is the largest subfamily in Araceae and consists of about 72 different genera, and 2,300 species. Many Aroideae have spiny pollen grains without a sporopollenin outer exine la ...

Lemnaceae Lemnoideae is a subfamily of flowering aquatic plants, known as duckweeds, water lentils, or water lenses. They float on or just beneath the surface of still or slow-moving bodies of fresh water and wetlands. Also known as bayroot, they arose ...

The

Wettstein system A system of plant taxonomy, the Wettstein system recognised the following main groups, according to Richard Wettstein's ''Handbuch der Systematischen Botanik'' (1901–1924). 3rd edition (1924) Outline Synopsis * Flagellatae p. 65 * ...

(1935) placed the order in class Monocotyledones and used a different circumscription, incorporating: *

Sparganiaceae Sparganiaceae is a family of flowering plants. Such a family was previously recognized by most taxonomists. The APG II system, of 2003 (unchanged from the APG system, 1998), also recognizes this family, and assigns it to the order Poales in the c ...

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) a ...

(1981) placed the order in subclass

Arecidae Arecidae is a botanical name at the rank of subclass. Circumscription of the subclass will vary with the taxonomic system being used (there are many such systems); the only requirement being that it includes the family Arecaceae. Arecidae in th ...

in class

Liliopsida Liliopsida Batsch (synonym: Liliatae) is a botanical name for the class containing the family Liliaceae (or Lily Family). It is considered synonymous (or nearly synonymous) with the name monocotyledon. Publication of the name is credited to Scopol ...

monocotyledons Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of t ...

with only one family: *

In the classification system of Dahlgren the Pandanales were in the

superorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

Pandaniflorae (also called Pandananae) with the single family Pandanaceae.

Angiosperm Phylogeny Group

The

APG III system The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a fur ...

(2009) places the Pandanales in the

. Both the APG III and

APG II 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 ...

systems include five families in this order. Since the morphology of the order varies on such scale, its classification and phylogeny are based on genetic analyses. Inside the order, some doubt remains about the position of the entirely mycoheterotrophic family Triuridaceae, since it is the only one on which genetic analyses have not yet been applied. With high probability, the family may be sister to the

Velloziaceae Velloziaceae is a family of monocotyledonous flowering plants. The APG II system, of 2003 (unchanged from the APG system, 1998), also recognizes this family, and assigns it to the order Pandanales. Relationships and evolution By contrast to oth ...

, but similarities with the family

Zingiberaceae Zingiberaceae () or the ginger family is a family of flowering plants made up of about 50 genera with a total of about 1600 known species of aromatic perennial herbs with creeping horizontal or tuberous rhizomes distributed throughout tropical Af ...

(which is a part of a whole different order –

Zingiberales The Zingiberales are flowering plants forming one of four orders in the commelinids clade of monocots, together with its sister order, Commelinales. The order includes 68 genera and 2,600 species. Zingiberales are a unique though morphological ...

) do not exclude the chance for a different phylogeny. The family Velloziaceae on its own is placed at the base of the tree. The

and

are sister groups, and they form a clade which on its own is sister to the

(a family composed of two more clades).

Evolution

The order

holds sister relationship with Pandanales by diverging from them around 121 million years ago in the mid-

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 th ...

. The formation of the

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

s took place with a difference of 2 million years between the orders - 116 Mya for the Dioscoreales and 114 Mya for the Pandanales. However, the

stem group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

of the Pandanales is much older and goes back to 130 Mya in the early

.Merckx. Diversification of myco-heterotrophic angiosperms: Evidence from Burmanniaceae. BMC Evolutionary Biology 2008
/ref>

Phylogeny

Subdivision

The composition of the order in APG III and APG II were slightly from that in the 1998

APG system The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved AP ...

, which used the circumscription *

APG III includes the following families; *

Distribution

The order contains members mainly distributed in all the

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

regions of the world, both New and Old World (including

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

). Also, a species is present in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

Ecology

The species are members of various ecological groups, including tropical shrubs, lianas and trees,

xerophytic A xerophyte (from Greek ξηρός ''xeros'' 'dry' + φυτόν ''phuton'' 'plant') is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert such as the Sahara or places in the Alps or th ...

plants,

mycoheterotrophs Myco-heterotrophy (from Ancient Greek, Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiosis, symbiotic relationship between certain kinds of plants and fungi, in which the plant gets a ...

, as well as different

representatives.

Uses

Several species in this order produce strap-like

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

used for basketry and mats; ''

Pandanus ''Pandanus'' is a genus of monocots with some 750 accepted species. They are palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics. The greatest number of species are found in Madagascar and Malaysia. Common names ...

'' (Pandanaceae) is used across

Oceania Oceania (, , ) is a region, geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern Hemisphere, Eastern and Western Hemisphere, Western hemispheres, Oceania is estimated to have a land area of ...

for thatch, basketry, and to make cloth, and ''

Carludovica palmata ''Carludovica palmata'' (Panama hat plant or toquilla palm) is a palm-like monocot plant. It is not a true palm. Its leaves are different from the leaves of true palms, and unlike true palms it does not develop a woody trunk. Its female flowers ...

'' (Cyclanthaceae) leaves are made into

Panama hat A Panama hat, also known as an Ecuadorian hat, a jipijapa hat, or a toquilla straw hat, is a traditional brimmed straw hat of Ecuadorian origin. Traditionally, hats were made from the plaited leaves of the ''Carludovica palmata'' plant, known ...

s. Other members as ''

Stemona ''Stemona'' is a genus of vines and subshrubs in the family Stemonaceae The Stemonaceae are a family of monocotyledonous flowering plants placed in the order Pandanales. The family consists of four genera with ca 37 known species distributed i ...

'' are present 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 action ...

and possess medical properties. Some species are used as

insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

s. Some species of ''Pandanus'' are used as ornamentals. ''

Pandanus amaryllifolius ''Pandanus amaryllifolius'' is a tropical plant in the ''Pandanus'' (screwpine) genus, which is commonly known as pandan (; ). It has fragrant leaves which are used widely for flavouring in the cuisines of Southeast Asia and South Asia. Occurre ...

'' is a common food

flavoring A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemoreceptors of the gusta ...

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 United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

and

karuka The karuka (''Pandanus julianettii'', also called karuka nut and ''Pandanus'' nut) is a species of tree in the family Pandanaceae and an important regional food crop in New Guinea. The nuts are more nutritious than coconuts, and are so popular ...

(''Pandanus julianettii'') is a

staple food A staple food, food staple, or simply a staple, is a food that is eaten often and in such quantities that it constitutes a dominant portion of a standard diet for a given person or group of people, supplying a large fraction of energy needs and ...

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

References

Bibliography

* *

External links

Merckx V. Cretaceous Origins of Myco-Heterotrophic Lineages in Dioscoreales. 2010

* ttp://www.mobot.org/MOBOT/Research/APweb/orders/pandanalesweb.htm#Pandanales Angiosperm Phylogeny Web: Pandanales
Berry, PE. Pandanales. Encyclopædia Britannica 2016
* * {{Taxonbar, from=Q269303 Angiosperm orders Extant Aptian first appearances