''Heliotropium'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 traditionally included in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Boraginaceae Boraginaceae, the Borago, borage or forget-me-not family, includes about 2,000 species of shrubs, trees, and herbs in 146 to 154 genus, genera with a worldwide distribution. The APG IV system from 2016 classifies the Boraginaceae as single famil ...

''s.l.'', but placed in the family Heliotropiaceae within the Boraginales

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 ...

, by the Boraginales Working Group.. There are around 325 species in this almost

cosmopolitan Cosmopolitan may refer to: Internationalism * World citizen, one who eschews traditional geopolitical divisions derived from national citizenship * Cosmopolitanism, the idea that all of humanity belongs to a single moral community * Cosmopolitan ...

genus, which are commonly known as heliotropes. They are highly toxic to dogs and cats, as well as to humans.

Etymology

The name "heliotrope" derives from the old idea that the

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s of these plants turned their rows of flowers to the Sun.Chittenden, Fred J. Ed., Royal Horticultural Society Dictionary of Gardening, Oxford 1951 Ἥλιος (''helios'') is

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

for "Sun", τρέπειν (''trepein'') means "to turn". The

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman Conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English pe ...

name "turnsole" has the same meaning. A Classical myth, told in

Ovid Publius Ovidius Naso (; 20 March 43 BC – AD 17/18), known in English as Ovid ( ), was a Augustan literature (ancient Rome), Roman poet who lived during the reign of Augustus. He was a younger contemporary of Virgil and Horace, with whom he i ...

's ''

Metamorphoses The ''Metamorphoses'' (, , ) is a Latin Narrative poetry, narrative poem from 8 Common Era, CE by the Ancient Rome, Roman poet Ovid. It is considered his ''Masterpiece, magnum opus''. The poem chronicles the history of the world from its Cre ...

'', imagines that the water nymph Clytie, in love with the sun god

Helios In ancient Greek religion and Greek mythology, mythology, Helios (; ; Homeric Greek: ) is the god who personification, personifies the Sun. His name is also Latinized as Helius, and he is often given the epithets Hyperion ("the one above") an ...

, was scorned by him. Wasting away, she transformed into the heliotrope, whose flowers supposedly always face the Sun.

Morphology

Like other members of the Heliotropiaceae, plants in the genus ''Heliotropium'' have 5-merous,

tetracyclic Tetracyclics are cyclic compound, cyclic chemical compounds that contain four fused ring (chemistry), rings of atoms, for example, Tröger's base. Some tricyclic compounds having three fused and one tethered ring (connected to main nucleus by ...

flowers and

actinomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirall ...

corollas. They likewise share in their characteristic terminal styles and highly modified stigmatic heads (basal stigma, infertile apex). Species in the genus are typically herbs or subshrubs exclusively and are characterized by their dry fruits that divide into two or four mericarpids. Heliotropium strigosum

Ecology and human use

Heliotropes are popular garden plants, most notably

garden heliotrope ''Heliotropium arborescens'', the garden heliotrope or just heliotrope, is a species of flowering plant in the borage family Boraginaceae, native to Bolivia, Colombia, and Peru. Common names also include cherry pie and common heliotrope. It is an ...

(''H. arborescens''). Some species are weeds, and many are hepatotoxic if eaten due to abundant

pyrrolizidine alkaloid Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Their use dates back centuries and is intertwined with the discovery, understanding, and e ...

s. There have been cases of canine death due to over-ingestion of this toxic plant. Some danaine

butterflies Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

, such as male queen butterflies, visit these plants, being attracted to their

s. Though it is not palatable and most animals will completely ignore it, there have been cases of horses, swine and cattle being poisoned due to contamination of hay.

Caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...

s of the grass jewel (''Freyeria trochylus''), a gossamer-winged butterfly, feed on '' H. strigosum''. The sap of heliotrope flowers, namely of European heliotrope ('' H. europaeum''), was used as a

food coloring Food coloring, color additive or colorant is any dye, pigment, or substance that imparts color when it is added to food or beverages. Colorants can be supplied as liquids, powders, gels, or pastes. Food coloring is commonly used in commercia ...

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...

and

Early Modern The early modern period is a Periodization, historical period that is defined either as part of or as immediately preceding the modern period, with divisions based primarily on the history of Europe and the broader concept of modernity. There i ...

French cuisine French cuisine is the cooking traditions and practices of France. In the 14th century, Guillaume Tirel, a Court (royal), court chef known as "Taillevent", wrote ''Le Viandier'', one of the earliest recipe collections of medieval France. In ...

. One of the most famous

ragtime Ragtime, also spelled rag-time or rag time, is a musical style that had its peak from the 1890s to 1910s. Its cardinal trait is its Syncopation, syncopated or "ragged" rhythm. Ragtime was popularized during the early 20th century by composers ...

piano A piano is a keyboard instrument that produces sound when its keys are depressed, activating an Action (music), action mechanism where hammers strike String (music), strings. Modern pianos have a row of 88 black and white keys, tuned to a c ...

melodies is " Heliotrope Bouquet", composed in 1907 by Louis Chauvin (the first two strains) and

Scott Joplin Scott Joplin (November 24, 1868 – April 1, 1917) was an American composer and pianist. Dubbed the "King of Ragtime", he composed more than 40 ragtime pieces, one ragtime ballet, and two operas. One of his first and most popular pieces, the ...

(the last two strains). Garden heliotrope is grown in Southern Europe as an ingredient for

perfume Perfume (, ) is a mixture of fragrance, fragrant essential oils or aroma compounds (fragrances), Fixative (perfumery), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agre ...

. The purplish facial rash of

dermatomyositis Dermatomyositis (DM) is a Chronic condition, long-term inflammatory disorder, inflammatory Autoimmune disease, autoimmune disorder which affects the skin and the muscles. Its symptoms are generally a skin rash and worsening muscle weakness over ...

is called "heliotrope rash" because it resembles ''E. arborescens''. Heliotrope is the main ingredient in perfumes such as Byredo Heliotropia, Molinard Heliotrope, Etro Heliotrope, Fragonard Héliotrope Gingembre and others.

Heliotrine and heliotridine

Seeds of the ''Heliotropium'' genus were discovered in the 1940s and 50s to be responsible for liver disease in populations that consumed them in large quantities, either inadvertently (as a contaminant of food crops) or deliberately (associated with the ingestion of herbal infusions for the treatment of certain ailments). The seeds contained high concentrations of pyrrolizidine alkaloids, identified mainly as the N-oxide of heliotrine (74%), and one or two other compounds similar in character to lasiocarpine. More recently, in 1993 and 2017, there have been reported cases of poisoning in Tajkistan from wheat contaminated with ''Heliotropium lasiocarpum'' seeds.

Taxonomy

Taxonomic revision supported through

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 ...

led to the recognition of '' Euploca'' as genus separate from ''Heliotropium''. In contrast, the genus '' Tournefortia'' was included in ''Heliotropium'' in a 2016 revision. Within ''Heliotropium'', there are four major

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

: *''Heliotropium'' sect. ''Heliothamnus'' *Old World ''Heliotropium'' clade *''Heliotropium'' sect. ''Cochranea'' *''Tournefortia'' clade, comprising ''Tournefortia'' sect. ''Tournefortia'' and all remaining New World ''Heliotropium species''

Origins of diversification

Three of the four major clades within ''Heliotropium'' have their centers of diversity in South America. The origins of the remaining

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

''Heliotropium'' clade can be traced back to a single colonization event from the

New World The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: ...

. ITS1 data shows there is a single characteristic long deletion between positions 61 and 111 in the genome of the Old World species, which defines the Old World ''Heliotropium'' species and separates them from their New World counterparts. Researchers concluded this is a single autapomorphic character from a single deletion event in the past. This most reasonably explains how the whole group may have come to share this characteristic deletion when comparing the genomes of Old World and New World ''Heliotropium''. The most likely driver of ''Heliotropium'' diversification across the three New World clades is early Andean uplift. Researchers identified three independent diversification events in the phylogeny of Andean ''Heliotropium'', whose timings correspond to late

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 ...

Andean uplift as well as the development of arid environments in South America during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58 ''Heliothamnus'' diversification is estimated to have taken place in the late Miocene. The age of ''Heliothamnus'' suggest that its diversification could have been triggered directly by the uplift of the Andes, something that would have promoted speciation in inner-Andean valleys and the Andean scrub. The majority of

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

''Heliothamnus''

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

in the region are restricted to these sorts of environments, further supporting this theory as the current leading theory explaining ''Heliothamnus'' diversification. Before the main rise of the Andes, ''Cochranea'' and ''Tournefortia'' coinhabited the Andean region at the same time and significant

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...

had not yet occurred. Once the Andes began to rise, ''Cochranea'' became isolated on the western side of the Andes while ''Tournefortia'' grew on the eastern side. This east-west division is still true of each group’s present distributions. The rise of the Andes affected the climate of the region and is believed to have contributed to the hyperaridity of the

Atacama Desert The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...

, something that could have acted as an additional barrier to filter out other ''Heliotropium'' species into the range of ''Cochranea'', thus promoting ''Cochranea'' speciation. Elevation differences would have also acted as barriers that helped promote speciation in ''Tournefortia'' species as many large groups within ''Tournefortia'' became well-adapted to high-elevation environments while other ''Heliotropium'' clades did not and thus could not coinhabit the same environments as ''Tournefortia''.

Selected species

Starr 010828-0009 Heliotropium anomalum var

Heliotropium europaeum 2004-10-xx-p1010074

* '' Heliotropium amplexicaule'' Vahl – clasping heliotrope, summer heliotrope, blue heliotrope * '' Heliotropium anderssonii'' * '' Heliotropium angiospermum'' * '' Heliotropium anomalum'' Hook. & Arn. – Polynesian heliotrope, Pacific heliotrope (Pacific Islands) ** ''Heliotropium anomalum'' var. ''argenteum'' – ''hinahina kū kahakai'' (

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

) * ''

Heliotropium arborescens ''Heliotropium arborescens'', the garden heliotrope or just heliotrope, is a species of flowering plant in the borage family Boraginaceae, native to Bolivia, Colombia, and Peru. Common names also include cherry pie and common heliotrope. It is an ...

'' – garden heliotrope, common heliotrope, cherry pie * '' Heliotropium argenteum'' * '' Heliotropium asperrimum'' R.Br. * '' Heliotropium balfourii'' * '' Heliotropium bracteatum'' R.Br. * '' Heliotropium conocarpum'' F.Muell. ex

Benth. George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studie ...

* '' Heliotropium crispatum'' F.Muell. ex Benth. * '' Heliotropium diversifolium'' F.Muell. ex Benth. * '' Heliotropium chenopodiaceum'' (A.DC.) Clos. * '' Heliotropium claussenii'' DC. * '' Heliotropium curassavicum'' L. – seaside heliotrope, salt heliotrope, monkey tail, quail plant, Chinese parsley; ''cola de mico'' ( Spanish) * '' Heliotropium dentatum'' * '' Heliotropium derafontense'' * '' Heliotropium ellipticum'' * '' Heliotropium epacrideum'' F.Muell. ex Benth. * '' Heliotropium europaeum'' L. – European heliotrope, European turnsole (Europe, Asia, and North Africa) * '' Heliotropium fasciculatum'' R.Br. * '' Heliotropium flintii'' F.Muell. ex A.S.Mitch. * '' Heliotropium foertherianum'' Diane & Hilger – tree heliotrope, velvet soldierbush, octopus bush (

South Asia South Asia is the southern Subregion#Asia, subregion of Asia that is defined in both geographical and Ethnicity, ethnic-Culture, cultural terms. South Asia, with a population of 2.04 billion, contains a quarter (25%) of the world's populatio ...

East Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...

Melanesia Melanesia (, ) is a subregion of Oceania in the southwestern Pacific Ocean. It extends from New Guinea in the west to the Fiji Islands in the east, and includes the Arafura Sea. The region includes the four independent countries of Fiji, Vanu ...

, western

Polynesia Polynesia ( , ) is a subregion of Oceania, made up of more than 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are called Polynesians. They have many things in ...

, northern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

) * '' Heliotropium foliatum'' R.Br. * '' Heliotropium glabellum'' R.Br. * '' Heliotropium heteranthum'' (F.Muell.) Ewart & O.B.Davies * '' Heliotropium indicum'' L. – Indian turnsole * '' Heliotropium kuriense'' * '' Heliotropium laceolatum'' Loefg. * '' Heliotropium lineariifolium'' Phil. * '' Heliotropium megalanthumn'' I.M.Johnst. * '' Heliotropium nigricans'' * ''

Heliotropium paniculatum ''Heliotropium'' is a genus of flowering plants traditionally included in the family Boraginaceae ''s.l.'', but placed in the family Heliotropiaceae within the Boraginales order, by the Boraginales Working Group.. There are around 325 species ...

'' R.Br. * '' Heliotropium pannifolium'' – St. Helena heliotrope (

Saint Helena Saint Helena (, ) is one of the three constituent parts of Saint Helena, Ascension and Tristan da Cunha, a remote British overseas territory. Saint Helena is a volcanic and tropical island, located in the South Atlantic Ocean, some 1,874 km ...

) (

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

, c. 1820) * '' Heliotropium pauciflorum'' R.Br. * '' Heliotropium paulayanum'' * ''

Heliotropium pleiopterum ''Heliotropium'' is a genus of flowering plants traditionally included in the family Boraginaceae ''s.l.'', but placed in the family Heliotropiaceae within the Boraginales order, by the Boraginales Working Group.. There are around 325 species i ...

'' F.Muell. * '' Heliotropium popovii'' * '' Heliotropium prostratum'' R.Br. * '' Heliotropium ramosissimum'' * '' Heliotropium riebeckii'' * '' Heliotropium shoabense'' * '' Heliotropium sinuatum'' (Miers) I.M.Johnst. * '' Heliotropium socotranum'' * '' Heliotropium stenophyllum'' * '' Heliotropium strigosum'' Willd. * '' Heliotropium tenellum'' * '' Heliotropium ventricosum'' R.Br. * '' Heliotropium wagneri'' * ''Heliotropium'' aff. ''wagneri'' ( Samhah,

Yemen Yemen, officially the Republic of Yemen, is a country in West Asia. Located in South Arabia, southern Arabia, it borders Saudi Arabia to Saudi Arabia–Yemen border, the north, Oman to Oman–Yemen border, the northeast, the south-eastern part ...

)

Formerly included here

* '' Chrozophora tinctoria'' (as ''H. tricoccum'') * '' Tournefortia gnaphalodes'' (L.) R.Br. ex Roem. & Schult. (as ''H. gnaphalodes'' L.)

References

External links

A Heliotrope
at Gardener's Path

at Chileflora {{Authority control Boraginaceae genera