''Heliotropium'' 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 ...

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 t ...

s in the heliotrope family,

Heliotropiaceae Heliotropiaceae is a cosmopolitan family of flowering plants with approximately 450 species worldwide, though it is concentrated especially in the tropics and subtropics. There are the following four genera in the family: * '' Heliotropium (''incl ...

. There are around 325 species in this almost

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

genus, which are commonly known as heliotropes (sg. ). It is highly toxic for dogs and cats.

Etymology

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

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are forme ...

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: Greece 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 ...

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 Englis ...

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

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

's ''

Metamorphoses The ''Metamorphoses'' ( la, Metamorphōsēs, from grc, μεταμορφώσεις: "Transformations") is a Latin narrative poem from 8 CE by the Roman poet Ovid. It is considered his '' magnum opus''. The poem chronicles the history of the ...

'', imagines that the water nymph

Clytie In Greek mythology, the name Clytie ( Ancient Greek: Κλυτίη, Ionic) or Clytia (, Attic and other dialects) may refer to: *Clytie (Oceanid), known for her unrequited love for Helios. Out of jealousy, Clytie arranged the death of Leucothoe ...

, in love with the sun god

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

, was betrayed 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 Merosity (from the greek "méros," which means "having parts") refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a ...

tetracyclic Tetracyclics are cyclic chemical compounds that contain four interconnected rings of atoms, e.g. Tröger's base. They have various pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or s ...

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

Heliotropium ovalifolium (Grey leaf heliotrope) W IMG 9949

Several heliotropes are popular garden plants, most notably garden heliotrope (''H. arborescens''). Some species are weeds, and many are

hepatotoxic Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn fr ...

if eaten in large quantities 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. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect he ...

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

butterflies Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises ...

, 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 Sy ...

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, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink. They come in many forms consisting of liquids, powders, gels, and pastes. Food coloring is used in both commercial food ...

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

and Early Modern

French cuisine French cuisine () is the cooking traditions and practices from France. It has been influenced over the centuries by the many surrounding cultures of Spain, Italy, Switzerland, Germany and Belgium, in addition to the food traditions of the re ...

. One of the most famous

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

piano The piano is a stringed keyboard instrument in which the strings are struck by wooden hammers that are coated with a softer material (modern hammers are covered with dense wool felt; some early pianos used leather). It is played using a keyboa ...

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

Scott Joplin Scott Joplin ( 1868 – April 1, 1917) was an American composer and pianist. Because of the fame achieved for his ragtime compositions, he was dubbed the "King of Ragtime." During his career, he wrote over 40 original ragtime pieces, one ra ...

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

perfume Perfume (, ; french: parfum) is a mixture of fragrant essential oils or aroma compounds (fragrances), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agreeable scent ...

. The purplish facial rash of

dermatomyositis Dermatomyositis (DM) is a long-term inflammatory disorder which affects skin and the muscles. Its symptoms are generally a skin rash and worsening muscle weakness over time. These may occur suddenly or develop over months. Other symptoms may inc ...

is called "heliotrope rash" because it resembles ''E. arborescens''.

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.(Dubrovinskii, 1947, 1952; Khanin, 1948; Bras et al., 1954, 1961; Bras & Hill, 1956; cited in World Health Organization (1988)
PYRROLIZIDINE ALKALOIDS
INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY, ENVIRONMENTAL HEALTH CRITERIA 80.

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 ''Euploca'' is an almost cosmopolitan genus of plants with around 100 species. It was first described by Thomas Nuttall in 1837. While part of the broadly defined Boraginaceae in the APG IV system from 2016, a revision of the order Boraginales f ...

'' 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 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 te ...

: *''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 that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by thei ...

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

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...

ITS1 Internal transcribed spacer (ITS) is the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript. ...

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 In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to ...

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 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 means "less recen ...

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

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million 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 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 found else ...

''Heliothamnus''

taxa In biology, a taxon (back-formation from ''taxonomy''; plural 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 nam ...

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 withi ...

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 ( es, Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in th ...

, 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

Indian Turnsole (Heliotropium indicum) W IMG 9746

Starr 050222-4160 Heliotropium procumbens

Heliotropium strigosum in Keesaraguda, AP W2 IMG 9143

* '' Heliotropium amplexicaule'' Vahl – clasping heliotrope, summer heliotrope, blue heliotrope * '' Heliotropium anderssonii'' * '' Heliotropium angiospermum'' * ''

Heliotropium anomalum ''Heliotropium anomalum'' is a species of flowering shrub in the borage family, Boraginaceae, that is native to the Hawaiian Islands, Guam, Christmas Island, Saipan, Tinian, Wake Island and New Caledonia. Common names include Polynesian heliotrop ...

'' Hook. & Arn. – Polynesian heliotrope, Pacific heliotrope (Pacific Islands) ** ''Heliotropium anomalum'' var. ''argenteum'' – ''hinahina kū kahakai'' (

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

) * '' Heliotropium arborescens'' – garden heliotrope, common heliotrope, cherry pie * ''

Heliotropium argenteum ''Heliotropium argenteum'' is a species of plant in the family Boraginaceae Boraginaceae, the borage or forget-me-not family, includes about 2,000 species of shrubs, trees and herbs in 146, to 156 genera with a worldwide distribution. T ...

'' * '' 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 ''Heliotropium curassavicum'', commonly called salt heliotrope (among other names), a species of flowering plant in the borage family (Boraginaceae). It is native to much of the Americas, from Canada to Argentina, including the West Indies and Ha ...

'' L. – seaside heliotrope, salt heliotrope, monkey tail, quail plant, Chinese parsley; ''cola de mico'' (

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

) * '' 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 of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;; ...

East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea ...

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

, western

Polynesia Polynesia () "many" and νῆσος () "island"), to, Polinisia; mi, Porinihia; haw, Polenekia; fj, Polinisia; sm, Polenisia; rar, Porinetia; ty, Pōrīnetia; tvl, Polenisia; tkl, Polenihia (, ) is a subregion of Oceania, made up of ...

, northern

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

) * '' Heliotropium foliatum'' R.Br. * '' Heliotropium glabellum'' R.Br. * '' Heliotropium heteranthum'' (F.Muell.) Ewart & O.B.Davies * ''

Heliotropium indicum ''Heliotropium indicum'', commonly known as Indian heliotrope, Indian turnsole is an annual, hirsute plant that is a common weed in waste places and settled areas. It is native to Asia. It is widely used in native medicine in Tamil Nadu, India. ...

'' L. – Indian turnsole * '' Heliotropium kuriense'' * '' Heliotropium laceolatum'' Loefg. * '' Heliotropium lineariifolium'' Phil. * '' Heliotropium megalanthumn'' I.M.Johnst. * '' Heliotropium nigricans'' * '' Heliotropium paniculatum'' R.Br. * '' Heliotropium pannifolium'' – St. Helena heliotrope (

Saint Helena Saint Helena () is a British overseas territory located in the South Atlantic Ocean. It is a remote volcanic tropical island west of the coast of south-western Africa, and east of Rio de Janeiro in South America. It is one of three constit ...

) (

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

, c. 1820) * '' Heliotropium pauciflorum'' R.Br. * '' Heliotropium paulayanum'' * '' Heliotropium pleiopterum'' 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 tenellum'', the pasture heliotrope, is a species of plant in the heliotrope family. It is native to southeastern and south-central North America, where it is found in limestone glades and rocky prairies. It is an annual Annual ...

'' * '' Heliotropium ventricosum'' R.Br. * '' Heliotropium wagneri'' * ''Heliotropium'' aff. ''wagneri'' ( Samhah,

Yemen Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and ...

)

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 {{Taxonbar, from=Q158082