Tradescantia
Encyclopedia
Tradescantia the Spiderworts, is a genus of an estimated 71 species of perennial plant
s in the family Commelinaceae
, native to the New World
from southern Canada
south to northern Argentina
. They are weakly upright to scrambling plants, growing to 30–60 cm tall, and are commonly found individually or in clumps in wooded areas and fields. The leaves
are long, thin and bladelike to lanceolate, from 3–45 cm long. The flower
s can be white, pink, or purple, but are most commonly bright blue, with three petal
s and six yellow anthers. The sap is mucilaginous
and clear. A number of the species flower in the morning and when the sun shines on the flowers in the afternoon they close, but can remain open on cloudy days until evening. Unlike most wildflowers of the United States and Canada (other than orchids and lilies), spiderworts are monocots and not dicots.
Though sometimes considered a weed
, spiderwort is cultivated for borders and also used in containers. Where it appears as a volunteer, it is often welcomed and allowed to stay.
The first species described, Virginia Spiderwort
T. virginiana, is native to the eastern United States
from Maine
to Alabama
, and Canada in southern Ontario
. Virginia Spiderwort was introduced to Europe
in 1629, where it is cultivated as a garden flower.
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).
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
, Manitoba
and Alberta
; it is however more common further south in the United States south to Texas
and Arizona
.
The three species of Wandering Jew, one native to eastern Mexico
, also belong to the Tradescantia genus. Other names used for various species include Spider-lily, Cradle-lily, Oyster-plant and Flowering Inch Plant.
The name of the genus honours the English
naturalists John Tradescant the Elder
(ca. 1570s – 1638) and John Tradescant the Younger
(1608-1662).
hairs of some Tradescantia are colored blue, but when exposed to sources of ionizing radiation
such as gamma ray
s, the cells mutate and change color to pink; they are one of the few tissues known to serve as an effective bioassay
for ambient radiation levels.
divided the genus into 11 sections, with the nominate section broken down into a further four series.
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
s in the family Commelinaceae
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 an estimated 650 species in 40 genera. Well known genera include...
, native to the New World
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
from southern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
south to northern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. They are weakly upright to scrambling plants, growing to 30–60 cm tall, and are commonly found individually or in clumps in wooded areas and fields. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are long, thin and bladelike to lanceolate, from 3–45 cm long. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s can be white, pink, or purple, but are most commonly bright blue, with three petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s and six yellow anthers. The sap is mucilaginous
Mucilage
Mucilage is a thick, gluey substance produced by most plants and some microorganisms. It is a polar glycoprotein and an exopolysaccharide.It occurs in various parts of nearly all classes of plant, usually in relatively small percentages, and is frequently associated with other substances, such as...
and clear. A number of the species flower in the morning and when the sun shines on the flowers in the afternoon they close, but can remain open on cloudy days until evening. Unlike most wildflowers of the United States and Canada (other than orchids and lilies), spiderworts are monocots and not dicots.
Though sometimes considered a weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
, spiderwort is cultivated for borders and also used in containers. Where it appears as a volunteer, it is often welcomed and allowed to stay.
The first species described, Virginia Spiderwort
Tradescantia virginiana
Tradescantia virginiana is a species of Tradescantia native to the eastern United States. Spiderwort is commonly grown in gardens and many garden spiderworts seem to be hybrids of T...
T. virginiana, is native to the eastern United States
Eastern United States
The Eastern United States, the American East, or simply the East is traditionally defined as the states east of the Mississippi River. The first two tiers of states west of the Mississippi have traditionally been considered part of the West, but can be included in the East today; usually in...
from Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
to Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
, and Canada in southern Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
. Virginia Spiderwort was introduced to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
in 1629, where it is cultivated as a garden flower.
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).
The Western Spiderwort
Tradescantia occidentalis
Tradescantia occidentalis is a plant in the dayflower family, Commelinaceae. It is listed as a threatened species in Canada....
T. occidentalis is listed as an endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
in Canada, where the northernmost populations of the species are found at a few sites in southern Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....
, Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
and Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
; it is however more common further south in the United States south to Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
.
The three species of Wandering Jew, one native to eastern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, also belong to the Tradescantia genus. Other names used for various species include Spider-lily, Cradle-lily, Oyster-plant and Flowering Inch Plant.
The name of the genus honours the English
Kingdom of England
The Kingdom of England was, from 927 to 1707, a sovereign state to the northwest of continental Europe. At its height, the Kingdom of England spanned the southern two-thirds of the island of Great Britain and several smaller outlying islands; what today comprises the legal jurisdiction of England...
naturalists John Tradescant the Elder
John Tradescant the elder
John Tradescant the elder , father of John Tradescant the younger, was an English naturalist, gardener, collector and traveller, probably born in Suffolk, England...
(ca. 1570s – 1638) and John Tradescant the Younger
John Tradescant the younger
John Tradescant the Younger , son of John Tradescant the elder, was a botanist and gardener, born in Meopham, Kent and educated at The King's School, Canterbury...
(1608-1662).
Stamen hairs and ionizing radiation
The cells of the stamenStamen
The stamen is the pollen producing reproductive organ of a flower...
hairs of some Tradescantia are colored blue, but when exposed to sources of ionizing radiation
Ionizing radiation
Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...
such as gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
s, the cells mutate and change color to pink; they are one of the few tissues known to serve as an effective bioassay
Bioassay
Bioassay , or biological standardization is a type of scientific experiment. Bioassays are typically conducted to measure the effects of a substance on a living organism and are essential in the development of new drugs and in monitoring environmental pollutants...
for ambient radiation levels.
Selected species
David HuntDavid Hunt (botanist)
David Richard Hunt is an English botanist and taxonomist. He is a specialist in cacti and notably compiled the 1999 CITES Cactaceae Checklist.- References :...
divided the genus into 11 sections, with the nominate section broken down into a further four series.
Section Austrotradescantia D.R.Hunt.
Section Campelia (L.C.Rich.) D.R.Hunt
Section Coholomia D.R.Hunt
Section Corinna D.R.Hunt
Section Cymbispatha (Pichon) D.R.Hunt
Section Mandonia D.R.Hunt
Section Parasetcreasea D.R.Hunt
Section Rhoeo (Hance) D.R.Hunt
Section Separotheca (Waterfall) D.R.Hunt
Section Setcreasea (K.Schum. & Sydow) D.R.Hunt |
Section Tradescantia
Section Zebrina (Schnizlein) D.R.Hunt.
Incertae sedis
|
Formerly placed here
- Callisia navicularis (Ortgies) D.R.Hunt (as T. navicularis Ortgies)
- Callisia warszewicziana (Kunth & C.D.Bouché) D.R.Hunt (as T. warszewicziana Kunth & C.D.Bouché)
- Gibasis geniculata (Jacq.) Rohweder (as T. geniculata Jacq.)
- Gibasis karwinskyana (Schult. & Schult.f.) Rohweder (as T. karwinskyana Schult. & Schult.f.)
- Gibasis pellucida (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 (Mart.) Handlos (as T. diuretica Mart.)
External links
- Flora of North America: Tradescantia (includes species in USA and Canada only)
- PlantSystematics: Tradescantia
- Western Spiderwort endangered in Canada