Lupinus aridorum
Encyclopedia
Lupinus aridorum is a rare species of lupine known by the common name scrub lupine. It is endemic to Florida
in the United States, where there were 10 known populations remaining in 2003. Fewer than 6000 individual plants were counted. It is threatened by the loss and degradation of its habitat. The scrub lupine is a federally listed endangered species
of the United States.
This plant was first collected in 1990, but rarely documented again until 1982, when it was described to science as a species. It is often treated as a variety of Lupinus westianus.
The scrub lupine is a biennial or perennial herb growing up to a meter tall. The leaves are oval with pointed tips, not palmate as in most other lupines. Each leaf blade may be up to 7 centimeters long by 4 wide and is borne on a long petiole
. The herbage is coated in silvery hairs. The inflorescence
is a raceme
-like spike of flowers up to 15 centimeters long borne on an erect stalk up to 13 centimeters in length. Each pealike flower is between 1 and 2 centimeters long and pale pink in color with a darker spot on the standard, or top, petal. The fruit is a hairy legume pod about 2 centimeters long. The plant is known to reach seven feet in diameter. The scrub lupine is easily identified in its habitat, being the only upright-growing lupine that has pink flowers.
The plant grows in the Florida scrub
of Central Florida
. It grows in well-drained white sand, or sometimes yellow sand, among sand pines (Pinus clausa). Other trees in the habitat may include slash pine (Pinus elliottii) and turkey oak (Quercus laevis). Shrub
s in the understory
include the Florida rosemary
(Ceratiola ericoides), scrub live oak
(Quercus geminata), and rusty lyonia (Lyonia ferruginea).
The Florida scrub is a highly endangered habitat type, and the lupine is mainly found in degraded strips or in areas that are in danger of being destroyed for development. The only known populations are in Orange
and Polk Counties
, areas of rapid growth and rapid loss of natural habitat. When it was listed under the Endangered Species Act
, the lupine was only found on private property which could not be protected. Since the last count in 2003, three to four of the 10 known populations have likely been extirpated
. Some sites are protected today, including at least one within the Lake Wales Ridge National Wildlife Refuge
; this is the only site that is guaranteed long-term protection from development.
The main threat to the species is the loss of its habitat to development and the improper management of remaining habitat. When it was listed, most of the occurrences were located between Orlando, Florida
, and the Walt Disney World complex, an area of busy growth. Land is being cleared for housing developments and related utilities, such as roads, and because most of the occurrences are still privately owned, they could be cleared at any time. Remaining habitat is affected by fire suppression. The Florida scrub is an ecosystem
which depends on a normal regime
of periodic wildfire
s for maintenance. Fire is largely prevented today in an effort to protect property, so the scrub lands become overgrown and plants, such as the lupine, that require open, bare spots for sunlight become shaded out. Most of the lupine's habitat is now degraded because it has gone without fire or mechanical removal of brush and vegetation.
Other threats include wilt
, a disease caused by the bacterium Xylella fastidiosa
.
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
in the United States, where there were 10 known populations remaining in 2003. Fewer than 6000 individual plants were counted. It is threatened by the loss and degradation of its habitat. The scrub lupine is a federally listed 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...
of the United States.
This plant was first collected in 1990, but rarely documented again until 1982, when it was described to science as a species. It is often treated as a variety of Lupinus westianus.
The scrub lupine is a biennial or perennial herb growing up to a meter tall. The leaves are oval with pointed tips, not palmate as in most other lupines. Each leaf blade may be up to 7 centimeters long by 4 wide and is borne on a long petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. The herbage is coated in silvery hairs. The inflorescence
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...
is a raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
-like spike of flowers up to 15 centimeters long borne on an erect stalk up to 13 centimeters in length. Each pealike flower is between 1 and 2 centimeters long and pale pink in color with a darker spot on the standard, or top, petal. The fruit is a hairy legume pod about 2 centimeters long. The plant is known to reach seven feet in diameter. The scrub lupine is easily identified in its habitat, being the only upright-growing lupine that has pink flowers.
The plant grows in the Florida scrub
Florida scrub
Florida scrub is an endangered temperate coniferous forest ecoregion of the state of Florida in the United States. It is found on coastal and inland sand ridges and is characterized by a xeromorphic plant community dominated by shrubs and dwarf oaks. Scrub soils, a type of entisol, are derived...
of Central Florida
Central Florida
Central Florida is a regional designation for the area surrounding Orlando in east central Florida, United States. The area represents the third largest population concentration in Florida, after the South Florida and Tampa Bay regions, respectively....
. It grows in well-drained white sand, or sometimes yellow sand, among sand pines (Pinus clausa). Other trees in the habitat may include slash pine (Pinus elliottii) and turkey oak (Quercus laevis). Shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s in the understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
include the Florida rosemary
Ceratiola ericoides
The Sandhill-rosemary, Florida-rosemary or Sand heath, Ceratiola ericoides, is a shrub usually included in the plant family Ericaceae, though treated by some botanists in the Empetraceae....
(Ceratiola ericoides), scrub live oak
Quercus geminata
Quercus geminata, commonly called Sand Live Oak, is an evergreen oak tree that is native to parts of the coastal southeastern United States, along the Atlantic Coast from Miami-Dade County, Florida northward to southeastern Virginia and along the Gulf Coast from Florida northward and westward to...
(Quercus geminata), and rusty lyonia (Lyonia ferruginea).
The Florida scrub is a highly endangered habitat type, and the lupine is mainly found in degraded strips or in areas that are in danger of being destroyed for development. The only known populations are in Orange
Orange County, Florida
Orange County is a county located in the U.S. state of Florida and is part of the Orlando-Kissimmee-Sanford Metropolitan Statistical Area . As of 2010 U.S. Census, the county had a population of 1,145,956....
and Polk Counties
Polk County, Florida
Polk County is located in central Florida between the Tampa Bay and Greater Orlando metropolitan areas. The county was established by the state government in 1861 on the eve of the American Civil War and named after former United States president James K. Polk. The county seat is Bartow and its...
, areas of rapid growth and rapid loss of natural habitat. When it was listed under the Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
, the lupine was only found on private property which could not be protected. Since the last count in 2003, three to four of the 10 known populations have likely been extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
. Some sites are protected today, including at least one within the Lake Wales Ridge National Wildlife Refuge
Lake Wales Ridge National Wildlife Refuge
The Lake Wales Ridge National Wildlife Refuge is part of the United States National Wildlife Refuge System, located in four separated areas on the Lake Wales Ridge east of US 27 between Davenport and Sebring Florida. The 1,194 acre refuge was established in 1990, to protect a host of plants and...
; this is the only site that is guaranteed long-term protection from development.
The main threat to the species is the loss of its habitat to development and the improper management of remaining habitat. When it was listed, most of the occurrences were located between Orlando, Florida
Orlando, Florida
Orlando is a city in the central region of the U.S. state of Florida. It is the county seat of Orange County, and the center of the Greater Orlando metropolitan area. According to the 2010 US Census, the city had a population of 238,300, making Orlando the 79th largest city in the United States...
, and the Walt Disney World complex, an area of busy growth. Land is being cleared for housing developments and related utilities, such as roads, and because most of the occurrences are still privately owned, they could be cleared at any time. Remaining habitat is affected by fire suppression. The Florida scrub is an ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
which depends on a normal regime
Fire regime
A fire regime is the pattern, frequency and intensity of the bushfires and wildfires that prevails in an area. It is an integral part of fire ecology, and renewal for certain types of ecosystems. If fires are too frequent, plants may be killed before they have matured, or before they have set...
of periodic wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
s for maintenance. Fire is largely prevented today in an effort to protect property, so the scrub lands become overgrown and plants, such as the lupine, that require open, bare spots for sunlight become shaded out. Most of the lupine's habitat is now degraded because it has gone without fire or mechanical removal of brush and vegetation.
Other threats include wilt
Wilt disease
A wilt disease is any number of diseases that affect the vascular system of plants. Attacks by fungi, bacteria, and nematodes can cause rapid killing of plants, large tree branches or even entire trees....
, a disease caused by the bacterium Xylella fastidiosa
Xylella fastidiosa
Xylella fastidiosa, a bacterium in the class Gammaproteobacteria, is an important plant pathogen that causes phoney peach disease in the southern United States, oleander leaf scorch, and Pierce's disease, and citrus variegated chlorosis disease in Brazil.-Pierce's disease:Pierce's disease was...
.