Harrisia fragrans
Encyclopedia
Harrisia fragrans is a rare species of cactus
Cactus
A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

 known by the common names fragrant prickly apple and Caribbean applecactus. It is endemic to Florida
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...

, where it is known mainly from St. Lucie County
St. Lucie County, Florida
St. Lucie County is a county located in the state of Florida. The county seat is the city of Fort Pierce. In the year 2000, the population was 192,695. As of the year 2010, the United States Census Bureau sets the population at 277,789.- History :...

. The plant's habitat has been almost completely consumed by development, leading to its rarity. It 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.

Description

This is an erect or spreading cactus with narrow, long stems which can well exceed one meter in length, at times approaching five meters. It is covered in long, yellow or yellow-tipped spines which may be up to 4 centimeters long. It produces enormous tubular flowers up to 20 centimeters long which are sweet-scented and white to pinkish in color. They bloom at night. The fruit is spherical and red or orange in color, measuring up to 6 centimeters wide. The fruits are a favorite food of local birds, which likely help to disperse
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...

 the seeds.The cactus has been noted to live at least 19 years, and in general has low fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...

; older, larger plants are more likely to survive, and they have higher fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...

, as well. Small plants may benefit from growing with nurse plants
Nurse tree
A nurse tree is a larger, faster-growing tree that shelters a smaller, slower-growing tree or plant. The nurse tree can provide shade, shelter from wind, or protection from animals who would feed on the smaller plant....

.

Habitat

The plant's favored natural habitat is mostly coastal hammocks
Hammock (ecology)
Hammocks are dense stands of hardwood trees that grow on natural rises of only a few inches higher than surrounding marshland that is otherwise too wet to support them. Hammocks are distinctive in that they are formed gradually over thousands of years rising in a wet area through the deposits of...

 with some shade, as the cactus can become desiccated
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...

 in full sun. Coastal hammocks of this kind have become uncommon as they have been cleared for development and heavily fragmented
Habitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...

.

There are ten confirmed occurrences of the plant, nine of which occur around Savannahs Preserve State Park in St. Lucie County and totalled 2150 individuals in the year 2002. The tenth confirmed occurrence is at the Canaveral National Seashore
Canaveral National Seashore
The Canaveral National Seashore is a National Seashore located between New Smyrna Beach and Titusville, Florida, in Volusia County and Brevard County, United States. The park, located on a barrier island, is home to more than 1,000 plant species and 310 bird species. CANA occupies 58,000 acres ...

 in Volusia County
Volusia County, Florida
Volusia County is a county located in the state of Florida. The U.S. Census Bureau 2010 official county's population was 494,593 . Its county seat is DeLand, and its most populous city is currently Deltona....

, and it contains about 96 plants. An occurrence has been reported in Indian River County
Indian River County, Florida
Indian River County is a county located in the Treasure Coast region in the U.S. state of Florida. As of 2000, the population was 112,947. The U.S. Census Bureau 2005 estimate for the county is 128,594...

, but it has not been confirmed. The cactus once grew in at least two places in Brevard County
Brevard County, Florida
Brevard County is a county located in the U.S. state of Florida, along the coast of the Atlantic Ocean. As of 2007 U.S. Census Bureau estimates, the population is 536,521, making it the 10th most populous county in the state. Influenced by the presence of the John F. Kennedy Space Center, Brevard...

, but these populations have 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...

.

Threats

Remaining populations of the cactus can now be found in sandy scrub habitat
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...

. The remaining habitat is degraded with the overgrowth of invasive plant species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

 such as love vine (Cassytha filiformis). While the cactus does not like full sun, it also cannot tolerate being shaded out by brush. Other threats to the plant have been all-terrain vehicle
All-terrain vehicle
An all-terrain vehicle , also known as a quad, quad bike, three wheeler, or four wheeler, is defined by the American National Standards Institute as a vehicle that travels on low pressure tires, with a seat that is straddled by the operator, along with handlebars for steering control...

s, herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...

s, feral pigs, and hurricane damage from wind and falling branches. Populations have been vandalized
Vandalism
Vandalism is the behaviour attributed originally to the Vandals, by the Romans, in respect of culture: ruthless destruction or spoiling of anything beautiful or venerable...

 with machete
Machete
The machete is a large cleaver-like cutting tool. The blade is typically long and usually under thick. In the English language, an equivalent term is matchet, though it is less commonly known...

s. Cacti have died from being buried in sand, and have been stolen by cactus enthusiasts and collectors. A scale insect
Scale insect
The scale insects are small insects of the order Hemiptera, generally classified as the superfamily Coccoidea. There are about 8,000 species of scale insects.-Ecology:...

, Diaspis echinocacti, sometimes eats the stems of the cactus, and some sort of caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...

 has been noted to inflict some damage. Woodpecker
Woodpecker
Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....

s have been observed poking holes in the stems, which injures the plants. Most of the remaining populations are within the bounds of a state park, so their habitat is safe from development.
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