The Santalales are an

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the

dicotyledon The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, ...

s. Well-known members of the Santalales include sandalwoods and the many species of

mistletoe Mistletoe is the common name for obligate parasite, obligate parasitic plant, hemiparasitic plants in the Order (biology), order Santalales. They are attached to their host tree or shrub by a structure called the haustorium, through which they ...

s. The order has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

, but is heavily concentrated in tropical and subtropical regions. It derives its name from its

type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

, ''

Santalum ''Santalum'' is a genus of woody flowering plants in the Santalaceae family, the best known and most commercially valuable of which is the Indian sandalwood tree, '' S. album''. Members of the genus are trees or shrubs. Most are root parasit ...

'' (sandalwood).

Overview

Many of the members of the order are

parasitic plant A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All Parasite, parasitic plants develop a specialized organ ...

s, mostly hemiparasites, able to produce sugars through

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

, but tapping the stems or roots of other plants to obtain water and minerals; some (e.g. ''

Arceuthobium The genus ''Arceuthobium'', commonly called dwarf mistletoes, is a genus of 42 species of parasitic plants that parasitize members of Pinaceae and Cupressaceae in North America, Central America, Asia, Europe, and Africa. Of the 42 species that h ...

'') are obligate

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s, have low concentrations of

chlorophyll Chlorophyll 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 allows plants to absorb energy ...

within their shoots (1/5 to 1/10 of that found in their host's foliage), and derive the majority of their sustenance from their hosts' vascular tissues (water,

micro- ''Micro'' (Greek letter μ, Mu (letter), mu, non-Italic type, italic) is a metric prefix, unit prefix in the metric system denoting a factor of one millionth (10−6). It comes from the Ancient Greek, Greek word (), meaning "small". It is the ...

and

macronutrient A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...

s, and sucrose). Most have

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s without testae (seed coats), which is unusual for flowering plants.

Classification

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 publish ...

of 2016 includes seven families. As in the earlier

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 f ...

, it was accepted that Olacaceae ''sensu lato'' was

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

but new family limits were not proposed as relationships were considered uncertain. , this seven-family division of the Santalales was explicitly accepted by the

World Flora Online World Flora Online is an Internet-based compendium of the world's plant species. Description The World Flora Online (WFO) is an open-access database, launched in October 2012 as a follow-up project to The Plant List, with the aim of publishi ...

, and implicitly by

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

, in that it accepted none of the extra families recognized by other sources. The seven families are: *

Balanophoraceae The Balanophoraceae are a subtropical to tropical family of obligate parasitic flowering plants, notable for their unusual development and formerly obscure affinities. In the broadest circumscription, the family consists of 16 genera. Alterna ...

Loranthaceae Loranthaceae, commonly known as the showy mistletoes, is a family of flowering plants. It consists of about 75 genera and 1,000 species of woody plants, many of them hemiparasites. The three terrestrial species are '' Nuytsia floribunda'' (the ...

Misodendraceae ''Misodendrum'' is a genus of hemiparasites which grow as mistletoes on various species of ''Nothofagus''. Its species are all restricted to South America. The name of the genus is incorrectly spelt in a number of ways, including ''Misodendron'' ...

Olacaceae Olacaceae is a family of flowering plants in the order Santalales. They are woody plants, native throughout the tropical regions of the world. , the circumscription of the family varies; some sources maintain a broad family, others split it int ...

Opiliaceae Opiliaceae is a family of flowering plants comprising 11 genera and 33 known species. It consists of tropical woody plants. Several genera contain parasitic species. The biggest genus, in number of species and in stature of the individual plant ...

Santalaceae The Santalaceae, sandalwoods, are a widely distributed family of flowering plants (including small trees, shrubs, perennial plants, perennial herbs, and epiphyte, epiphytic climbersHewson & George t al.'Santalaceae'' taxonomy, 1984, pp. 191-1 ...

Schoepfiaceae Schoepfiaceae is a family of flowering plants recognized in the APG III system of 2009. The family was previously only recognized by few taxonomists; the plants in question usually being assigned to family Olacaceae and Santalaceae. The genus '' ...

When only these families are recognized, one possible phylogenetic relationship among them is shown below. Support for some of the nodes is weak, and at least two families, Olacaceae '' s.l.'' and Balanophoraceae ''s.l.'', are not monophyletic: A summary of the circumscription and phylogeny of the Santalales published in 2020 used 20 rather than seven families. Olacaceae ''s.l.'' was divided into seven families, Balanophoraceae ''s.l.'' was divided into two, and Santalaceae ''s.l.'' into seven. , the

Angiosperm Phylogeny Website The Angiosperm Phylogeny Website (or APweb) is a website that presents up-to-date research on the phylogeny and taxonomy of flowering plants (angiosperms) in what is intended to be a user-friendly way. The site is hosted by the Missouri Botanical ...

accepted the families resulting from the division of Olacaceae ''s.l.'' and Balanophoraceae ''s.l.'' but not those from the division of Santalaceae ''s.l.''

Earlier systems

In the

classification system Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...

of Dahlgren, the Santalales were in the

superorder Order () 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 recognized ...

Santaliflorae (also called Santalanae). The

Cronquist system The Cronquist system is a list of systems of plant taxonomy, taxonomic classification system of angiosperms, flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of ...

(1981) used this circumscription: * order Santalales :* family Medusandraceae – sole genus ''

Medusandra ''Medusandra'' is a genus of flowering plants in the family Peridiscaceae."Peridiscaceae" At: Peter F. Stevens (2001 onwards). Angiosperm Phylogeny Website. At: Missouri Botanical Garden Website. (see external links below) It has two species, '' ...

'' now in family

Peridiscaceae Peridiscaceae is a Family (biology), family of flowering plants in the Order (biology), order Saxifragales.Peter F. Stevens. 2001 onwards. "Peridiscaceae". At: Angiosperm Phylogeny Website At: Missouri Botanical Garden Website. (see ''External li ...

, order

Saxifragales Saxifragales is an order (biology), order of flowering plants in the Superrosids, superrosid clade of the eudicots. It contains 15 Families (biology), families and around 100 genera, with nearly 2,500 species. Well-known and economically import ...

:* family Dipentodontaceae – now in order

Huerteales Huerteales is the botanical name for an order of flowering plants.Peter F. Stevens (2001 onwards). "Huerteales". In: Angiosperm Phylogeny Website. In: Missouri Botanical Garden Website. (see ''External links'' below) It is one of the 17 orders t ...

in APG IV :* family

:* family

Viscaceae Viscaceae is a taxonomic family name of flowering plants. In this circumscription, the family includes the several genera of mistletoes. This family name is currently being studied and under review as in past decades, several systems of plant tax ...

- sunk into Santalaceae ''s.l.'' in the seven-family system :* family Eremolepidaceae - sunk into Santalaceae ''s.l.'' in the seven-family system :* family

Gallery of type genera

Balanophora indica2.jpg , alt=flowers , ''

Balanophora fungosa ''Balanophora fungosa'', sometimes known as fungus root, is a flowering plant in the family Balanophoraceae and occurs in South Asia, Southeast Asia, Australia and some Pacific islands. It is a parasite growing on the roots of rainforest trees. T ...

'' Loranthus europaeus (Riemenmistel) IMG 9783.jpg, alt=flowers and foliage , ''

Loranthus europaeus ''Loranthus'' is a genus of parasitic plants that grow on the branches of woody trees. It belongs to the family Loranthaceae, the showy mistletoe family. In most earlier systematic treatments it contains all mistletoe species with bisexual flower ...

'' Misodendrum punctulatum.jpg , alt=flowers and foliage , ''

Misodendrum punctulatum ''Misodendrum punctulatum'' is a species of parasitic plant which grows as a mistletoe on various species of ''Nothofagus'', especially on deciduous species like '' N. antarctica'' and '' N. pumilio'', but also on the evergreen '' N. dombeyi'' a ...

'' Olax imbricata Roxb. (8503288374).jpg , alt=flowers and foliage , ''

Olax imbricata ''Olax'' is a plant genus in the family Olacaceae. It includes 52 species native to the tropics of South America, Africa, Asia, and Australia. The name derives from the Latin, ''olax'' (malodorous), and refers to the unpleasant scent of some o ...

'' Opilia amentacea.jpg , alt=botanical illustration , '' Opilia amentacea'' Santalum album - Indian Botanic Garden - Howrah 2013-03-31 5743.JPG , alt=foliage , ''

Santalum album ''Santalum album'' is a small tropical tree, and the traditional source of sandalwood oil. It is native to Indonesia (Java and the Lesser Sunda Islands), the Philippines, and Western Australia. It is commonly known as the true sandalwood, white ...

'' Schoepfia brasiliensis A.DC. - Flickr - Alex Popovkin, Bahia, Brazil (11).jpg , alt=foliage , '' Schoepfia brasiliensis''

References

* *
Santalales on the Parasitic Plant Connection web page

NCBI Taxonomy Browser
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