''Tradescantia'' () 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 85 species
of
herbaceous perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...
wildflowers in the family
Commelinaceae
Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with about 731 kno ...
, native to the
Americas
The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World.
Along with th ...
from southern
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
to northern
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
, including the
West Indies
The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greate ...
. Members of the genus are known by many common names, including inchplant, wandering jew, spiderwort, and dayflower.
''Tradescantia'' grow , and are commonly found individually or in clumps in wooded areas and open fields. They were introduced into Europe as
ornamental plant
Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...
s in the 17th century and are now grown in many parts of the world. Some species have become naturalized in regions of
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
,
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 are ...
,
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 ...
, and
Australia, and on some oceanic islands.
The genus's many species are of interest to
cytogenetics
Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis an ...
because of evolutionary changes in the structure and number of their
chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
s. They have also been used as
bioindicator
A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...
s for the detection of
environmental
A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...
mutagens.
Some species have become
pests to
cultivated crop
A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponics ...
s and considered invasive.
Description
''Tradescantia'' are herbaceous perennials and include both climbing and trailing species, reaching in height. The
leaves are long, thin and blade-like to lanceolate, from . 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 ...
s can be white, pink, purple or blue, with three
petals and six yellow
anthers (or rarely, four
petals and eight
anthers). The sap is
mucilaginous
Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion. The direction of their movement is always opposite to that of the secretion of ...
and clear.
A number of species have flowers that last for only a day, opening in the morning and closing by the evening.
Etymology
The scientific name of the genus chosen by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
honours the English naturalists and explorers
John Tradescant the Elder
John Tradescant the Elder (; c. 1570s – 15–16 April 1638), father of John Tradescant the Younger, was an English naturalist, gardener, collector and traveller. On 18 June 1607 he married Elizabeth Day of Meopham in Kent, England. She had been ...
(c. 1570s – 1638) and
John Tradescant the Younger
John Tradescant the Younger (; 4 August 1608 – 22 April 1662), son of John Tradescant the Elder, was a botanist and gardener. The standard author abbreviation Trad. is applied to species he described.
Biography
Son of John Tradescant th ...
(1608–1662), who introduced many new plants to English gardens. Tradescant the Younger mounted three expeditions to the new colony of
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
.
From there the
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...
, ''
Tradescantia virginiana'', was brought to England in 1629.
Plants of the genus are called by many
common names, varying by region and country. The name "inchplant" is thought to describe the plant's fast growth, or the fact that leaves are an
inch apart on the stem. "Spiderwort" refers to the sap which dries into web-like threads when a stem is cut. The name "dayflower", shared with other members of the
Commelinaceae
Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with about 731 kno ...
family, refers to the flowers which open and close within a single day.
The controversial name "wandering Jew" originates from the
Christian myth of the
Wandering Jew
The Wandering Jew is a mythical immortal man whose legend began to spread in Europe in the 13th century. In the original legend, a Jew who taunted Jesus on the way to the Crucifixion was then cursed to walk the Earth until the Second Coming. Th ...
, condemned to wander the earth for taunting
Jesus
Jesus, likely from he, יֵשׁוּעַ, translit=Yēšūaʿ, label= Hebrew/ Aramaic ( AD 30 or 33), also referred to as Jesus Christ or Jesus of Nazareth (among other names and titles), was a first-century Jewish preacher and religiou ...
on the way to his
crucifixion
Crucifixion is a method of capital punishment in which the victim is tied or nailed to a large wooden cross or beam and left to hang until eventual death from exhaustion and asphyxiation. It was used as a punishment by the Persians, Carthagi ...
.
[Anderson, George K. ''The Legend of the Wandering Jew.'' Providence: Brown University Press, 1965. xi, 489 p.; ] In recent years there have been efforts to stop using this and other potentially offensive common names,
in favour of alternatives such as "wandering dude".
In Spanish, ''Tradescantia'' plants are sometimes referred to as ''flor de Santa Lucía'' (
Saint Lucy
Lucia of Syracuse (283–304), also called Saint Lucia ( la, Sancta Lucia) better known as Saint Lucy, was a Roman people, Roman Christian martyr who died during the Diocletianic Persecution. She is venerated as a saint in the Catholic Church, ...
's flower), in reference to the Saint's reputation as the patron saint of sight, and the use of the juice of the plant as eye drops to relieve congestion.
Taxonomy
Subdivisions and species
![IMG 5708-Tradescantia brevifolia](https://upload.wikimedia.org/wikipedia/commons/1/1c/IMG_5708-Tradescantia_brevifolia.jpg)
The number of species and infrageneric taxa has changed throughout history. The first major classification proposed by Hunt (1980) included 60 species divided into eight sections, with one section divided into a further four series.
Hunt's 1986 revision united several small genera with ''Tradescantia'' as sections, resulting in a total of twelve sections comprising 68 species,
and this infrageneric classification was accepted for several decades.
A recent study by Pellegrini (2017) proposed a new classification based on recent morphological research, dividing the genus into five subgenera.
The Royal Botanic Gardens, Kew currently recognises 85 species.
Formerly placed here
*
''Tradescantia'' × ''andersoniana'' W.Ludw. & Rohweder The name was published with no description, so is not a valid
botanical name
A botanical name is a formal scientific name conforming to the ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the ''Internat ...
; the taxon is now treated as a
cultivar group.
*''
Callisia navicularis
''Callisia navicularis'' is a species of flowering plant in the family Commelinaceae. It has gained the Royal Horticultural Society's Award of Garden Merit
The Award of Garden Merit (AGM) is a long-established annual award for plants by the B ...
''
(Ortgies) D.R.Hunt (as ''T. navicularis''
Ortgies)
*''
Callisia warszewicziana
''Callisia'' is a genus of flowering plants in the Tradescantia, spiderwort family, Commelinaceae. Members of the genus are commonly known as roselings. It is native to the Western Hemisphere from the southern United States to Argentina. The gen ...
''
(Kunth & C.D.Bouché) D.R.Hunt (as ''T. warszewicziana''
Kunth & C.D.Bouché)
*''
Gibasis geniculata
''Gibasis geniculata'' is a trailing plant in the family Commelinaceae, native to Mexico and tropical America.
The cultivated plant commonly known as Tahitian bridal veil is often labelled as ''Gibasis geniculata'', however its true species is ...
''
(Jacq.) Rohweder (as ''T. geniculata''
Jacq.)
*''
Gibasis karwinskyana
''Gibasis'' is a genus of flowering plants within the Commelinaceae family, first described in 1837. It is native to the Western Hemisphere from Texas and the West Indies south to Argentina, with most of the species native to Mexico.
It is cl ...
''
(Schult. & Schult.f.) Rohweder (as ''T. karwinskyana''
Schult. & Schult.f.)
*''
Gibasis pellucida
''Gibasis pellucida'', also known as Tahitian bridal veil, is a trailing plant in the family Commelinaceae that is native to the West Indies, southwest Texas, Argentina and Mexico.
In horticulture, the plant is often mislabelled as the related s ...
''
(M.Martens & Galeotti) D.R.Hunt (as ''T. pellucida''
M.Martens & Galeotti)
*''
Siderasis fuscata''
(Lodd. et al.) H.E.Moore (as ''T. fuscata''
Lodd. et al.)
*''
Tinantia anomala''
(Torr.) C.B.Clarke (as ''T. anomala''
Torr.)
*''
Tripogandra diuretica
''Tripogandra'' is a genus of flowering plants in the spiderwort family, Commelinaceae. It is native to the Western Hemisphere from central Mexico and the West Indies south to Argentina.Davidse, G., M. Sousa Sánchez & A.O. Chater. 1994. Alismata ...
''
(Mart.) Handlos (as ''T. diuretica''
Mart.)
* ''
Elasis hirsuta''
(Kunth) D.R.Hunt (as ''T. hirsuta'')
Distribution and habitat
The first species described, the
Virginia spiderwort, ''T. virginiana'', is native to the
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 ...
from
Maine
Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and ...
to
Alabama
(We dare defend our rights)
, anthem = "Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery
, LargestCity = Huntsville
, LargestCounty = Baldwin County
, LargestMetro = Greater Birmingham
, area_total_km2 = 135,765 ...
, and Canada in southern
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
. Virginia spiderwort was introduced to
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
in 1629, where it is cultivated as a garden flower.
The natural range of the genus as a whole spans nearly the entire length and width of mainland North America, from Canada through Mexico and Central America, and thrives in a great diversity of temperate and tropical habitats. It is frequently found in thinly wooded deciduous forests, plains, prairies, and healthy fields, often alongside other native wildflowers.
Conservation
The
western spiderwort ''T. occidentalis'' is listed as an
endangered species in Canada, where the northernmost populations of the species are found at a few sites in southern
Saskatchewan
Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...
,
Manitoba
, image_map = Manitoba in Canada 2.svg
, map_alt = Map showing Manitoba's location in the centre of Southern Canada
, Label_map = yes
, coordinates =
, capital = Winn ...
and
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
; it is more common further south in the United States to
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
and
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
.
Cultivation
![Tradescantia_greece](https://upload.wikimedia.org/wikipedia/commons/3/37/Tradescantia_greece.jpg)
Spiderworts are popular in Europe and North America as ornamental plants. Temperate species are grown as garden plants while tropical species, such as ''T. zebrina'' and ''T. spathacea'', are used as house plants. Their popularity and easy spreading nature has led to some species being considered serious weeds in certain places (see
below).
Most cold-hardy garden plants belong to the Andersoniana Group (often referred to with the
invalid name ''Tradescantia'' × ''andersoniana''). This is a group of interspecific hybrids developed from ''
Tradescantia virginiana'', ''
T. ohiensis'', and ''
T. subaspera'', which have overlapping ranges within continental North America. These plants are clump-forming herbaceous perennials, with individual cultivars mainly differing in flower colour. The cultivars in this group include 'Blue Stone', 'Isis', 'Innocence', 'Snowcap', 'Osprey', 'Iris Pritchard', 'Pauline', 'Red Cloud' and 'Karminglut' ('Carmine Glow'). 'Caerulea Plena' is a double-flowered variety with dark blue flowers. 'Concord Grape' (Andersoniana Group) has won the
Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...
's
Award of Garden Merit.
A wide range of tender tropical species are cultivated as houseplants or outdoor annuals, including ''Tradescantia zebrina'', ''T. fluminensis'', ''T. spathacea'', ''T. sillamontana'', and ''T. pallida''.
They are typically grown for their foliage, and many have colourful variegated patterns of silver, purple, green, pink, and gold.
Popular tropical cultivars include ''T. zebrina'' 'Silver Plus', ''T. zebrina'' 'Burgundy', ''T. fluminensis'' 'Lavender', ''T. fluminensis'' 'Variegata', ''T. mundula'' 'Laekenensis', ''T. pallida'' 'Purple Heart', ''Tradescantia'' 'Nanouk', and ''Tradescantia'' 'Pale Puma'. The species ''Tradescantia zebrina'', and the cultivars ''Tradescantia'' 'Quicksilver' and ''Tradescantia pallida'' 'Purpurea' have received the
Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...
's
Award of Garden Merit.
Weeds
Due to its ready propagation from stem fragments and its domination of the ground layer in many forest environments, ''
T. fluminensis'' has become a major environmental
weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
in Australia, New Zealand and the southern United States. Other species considered invasive weeds in certain places include ''T. pallida'', ''T. spathacea'', and ''T. zebrina''.
Toxicity
Some members of the genus ''Tradescantia'' may cause allergic reactions in pets (especially cats and dogs) characterised by red, itchy skin.
Notable culprits include ''T. albiflora'' (scurvy weed), ''T. spathacea'' (Moses in the cradle), and ''T. pallida'' (purple heart).
Uses
Native Americans used ''T. virginiana'' to treat a number of conditions, including stomachache. It was also used as a food source. The cells of the
stamen hairs of some ''Tradescantia'' are colored blue, but when exposed to sources of
ionizing radiation such as
gamma ray
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...
s or pollutants like sulphur dioxide from industries, the cells mutate and change color to pink; they are one of the few tissues known to serve as an effective
bioassay
A bioassay is an analytical method to determine the concentration or potency of a substance by its effect on living animals or plants (''in vivo''), or on living cells or tissues(''in vitro''). A bioassay can be either quantal or quantitative, dir ...
for ambient radiation levels.
Gallery
Image:PurpHeart1.jpg, Front view of leaves of '' Tradescantia pallida'' 'Purpurea'
Image:PurpHeart2.jpg, Back view of leaves of '' Tradescantia pallida'' 'Purpurea'
Image:Zebrina1.jpg, Front view of leaves of '' Tradescantia zebrina'' 'Tricolor'
Image:Zebrina2.jpg, Back view of leaves of '' Tradescantia zebrina'' 'Tricolor'
Image:Smithsoniangardens15.jpg, A budding ''Tradescantia'' flower
Image:0 Tradescantia 'Red grape' - Misère - JPG1.jpg, ''Tradescantia'' 'Red Grape'
References
Bibliography
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*
*
*
*
External links
*
*
Flora of North America: ''Tradescantia''(includes species in USA and Canada only)
PlantSystematics: ''Tradescantia''
{{Authority control
Commelinales genera