Echinacea tennesseensis
Encyclopedia
Echinacea tennesseensis, also known as the Tennessee coneflower or Tennessee purple coneflower, is a flowering plant
in the family Asteraceae
, endemic
to the cedar glades
of the central portion of the U.S. state
of Tennessee
.
perennial plant
growing to 75 centimetres (2.5 ft) tall. The leaves
are hairy, lanceolate, and arranged in a basal whorl with only a few small leaves on the flower stems.
The flower
s are produced in a capitulum
(flowerhead) up to 8 cm broad, with a ring of purple ray florets surrounding the brown disc florets.
A noticeable characteristic is its generally erect ray flowers, in contrast to the more drooping rays of its most similar congener, E. angustifolia
(widespread throughout the prairie
of the central U.S.) and other common Echinacea species such as E. purpurea
.
, and is found in fewer than 10 locations in Davidson
, Wilson, and Rutherford
Counties.
It has been hypothesized that an ancestral Echinacea species spread into middle Tennessee during the hypsothermal period following the last ice age, when conditions were drier and prairies extended into much of the central eastern U.S. that is now forested. As conditions became wetter, the Echinacea populations became isolated on the prairie-like habitat of the cedar glades which were eventually surrounded by forest. This isolation resulted in divergence and speciation of E. tennesseensis.
and its recovery has been aided by the purchase of habitat
by the Nature Conservancy
and the State of Tennessee. The United States Fish and Wildlife Service
has proposed that this plant be removed from the endangered species list because all the former threats to the species are eliminated or reduced. The Service ruled that the plant will be delisted effective September 2, 2011.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the family Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
, endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to the cedar glades
Cedar glades
A cedar glade is a habitat type unique to the central eastern United States. Cedar glades occur where limestone bedrock occurs near or at the surface. The glade areas proper have very shallow soil or exposed bedrock in some areas. Because of the shallow soil and the extreme conditions created by...
of the central portion of the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
.
Description
Echinacea tennesseensis is a herbaceousHerbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
perennial plant
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...
growing to 75 centimetres (2.5 ft) tall. 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 hairy, lanceolate, and arranged in a basal whorl with only a few small leaves on the flower stems.
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 are produced in a capitulum
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
(flowerhead) up to 8 cm broad, with a ring of purple ray florets surrounding the brown disc florets.
A noticeable characteristic is its generally erect ray flowers, in contrast to the more drooping rays of its most similar congener, E. angustifolia
Echinacea angustifolia
Echinacea angustifolia is a herbaceous plant species in Asteraceae. The plants grow tall with spindle-shaped taproots that are often branched. The stems and leaves are moderately to densely hairy.E. angustifolia blooms late spring to mid summer...
(widespread throughout the prairie
Prairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...
of the central U.S.) and other common Echinacea species such as E. purpurea
Echinacea purpurea
Echinacea purpurea is a species of flowering plant in the genus Echinacea. Its cone-shaped flowering heads are usually, but not always purple. It is native to eastern North America and present to some extent in the wild in much of the eastern, southeastern and midwest United States...
.
Distribution
Echinacea tennesseensis is a federally listed endangered speciesEndangered 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...
, and is found in fewer than 10 locations in Davidson
Davidson County, Tennessee
Davidson County is a county located in the U.S. state of Tennessee. As of 2010, the population was 626,681. Its county seat is Nashville.In 1963, the City of Nashville and the Davidson County government merged, so the county government is now known as the "Metropolitan Government of Nashville and...
, Wilson, and Rutherford
Rutherford County, Tennessee
Rutherford County is a county located in the U.S. state of Tennessee. As of the 2010 census, it is the state's fifth-largest county by population with 262,604 people, an increase of 44.3 percent over the 2000 population of 182,023. Its county seat is Murfreesboro, which is also the geographic...
Counties.
It has been hypothesized that an ancestral Echinacea species spread into middle Tennessee during the hypsothermal period following the last ice age, when conditions were drier and prairies extended into much of the central eastern U.S. that is now forested. As conditions became wetter, the Echinacea populations became isolated on the prairie-like habitat of the cedar glades which were eventually surrounded by forest. This isolation resulted in divergence and speciation of E. tennesseensis.
Endangered species
The Tennessee coneflower was one of the federally listed endangered plant speciesEndangered 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...
and its recovery has been aided by the purchase of habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
by the Nature Conservancy
The Nature Conservancy
The Nature Conservancy is a US charitable environmental organization that works to preserve the plants, animals, and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive....
and the State of Tennessee. The United States Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
has proposed that this plant be removed from the endangered species list because all the former threats to the species are eliminated or reduced. The Service ruled that the plant will be delisted effective September 2, 2011.