Lava cactus
Encyclopedia
The lava cactus is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 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...

 and the sole species of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Brachycereus. The plant is a colonizer of lava fields, hence its common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

.

Physical features

The plant has soft furry spines and grows in clumps to a height of about two feet (60 cm). New growth is yellow, turning to brown, which darkens to gray with age. The creamy white flowers are visible in the early morning hours only, and normally fade by 8 in the morning.

Habitat

As its name suggests, the lava cactus occurs exclusively on barren lava fields, lying at sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

. Not only is it one of the few plants that survive in this extremely dry, challenging habitat, it is often one of the first plants to colonise a fresh lava flow.

Biology

Despite the scientific interest that the Galápagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...

 have received ever since Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

 visited in 1835, and the numerous observations of the lava cactus, the biology of this plant remains poorly known.

Like all cacti, this succulent plant
Succulent plant
Succulent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climates or soil conditions. Succulent plants store water in their leaves, stems, and also in roots...

 is capable of storing moisture in its stems when water is available, enabling it to survive periods of drought, and the spines, which are actually the leaves of the cactus, provide defense against any plant-eating animals. The lava cactus flowers very briefly, with its cream-coloured blooms opening just before dawn, and usually shrivelling by seven or eight o’clock in the morning.

Threats

While the Galápagos are a protected area, and are considered one of the most unspoiled areas remaining on the planet, the fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...

 and flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...

 of these islands still face major threats, such as introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

, pressure from increasing tourist numbers, and a decline in the maintenance of protective laws. However, the lava cactus is not currently known to be facing any specific threats, and is considered to be Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...

 based primarily on its restricted distribution.

Conservation

The unique biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

 of the Galápagos has been recognized and these islands are well protected as a result, being classified as a National Park
National park
A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...

 and a Natural World Heritage Site. More specifically for the lava cactus, the government of Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

prohibits the collection of any plant in the Galápagos.

External links

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