''Melocactus azureus'' is a species of

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gre ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, where it is known only from

Bahia Bahia ( , , ; meaning "bay") is one of the 26 states of Brazil, located in the Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo, Minas Gerais, and Rio de Janeiro) and the 5th-largest ...

. It is locally abundant but the populations are fragmented and vulnerable to habitat degradation.

Description

''Melocactus azureus'' has a striking frosty blue epidermis. It's cylindrical stem is(9-)14-30(-45cm) tall and 14-20 centimeters in diameter, green, grey-green, but never

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), g ...

like subspecies

Melocactus azureus ferreophilus ''Melocactus'' (melon cactus), also known as the Turk's cap cactus, is a genus of cactus with about 30–40 species. They are native to the Caribbean, western Mexico through Central America to northern South America, with some species along the A ...

with

mucilage Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion. The direction of their movement is always opposite to that of the secretion of ...

present in the cortical tissues. It has 9-10 ribs and the spines are black to reddish, overlaid with gray, and some are hooked in seedlings while the central spines are slightly curved to straight and the radial spines are very stout. The flowers are small, 15-23mm long and 4-11 mm in diameter, and pink to magenta, it flowers in spring to late autumn. The fruits are small, white to able pink and seeds are smooth. It has the

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...

number 2n = 44.

Habitat

''Melocactus azureus'' is endemic to central, northern, and easter Brazil at altitudes of 450-800 metres above sea level. This species has a small range and is only in low-lying outcrops of limestone, tt occurs in fragmented populations from a few hundred to millions. A major threat to the species is habitat loss for agriculture, vegetation is destroyed when the surrounding

caatinga forest Caatinga (, ) is a type of semi-arid tropical vegetation, and an ecoregion characterized by this vegetation in interior northeastern Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation" (''caa'' = forest, veg ...

is cleared causing a decline of wild populations. The change has an impact on the outcrops were the species grows as well, making them prone to invasive species.

Cultivation

''Melocactus azureus'' has a relatively rapid growth rate given the best conditions. These tropical cacti are not recommended for beginners as they are not easy to grow. It grows well in very porous standard cactus mix soil, this cactus preferes very bright light however not as much as most arid growing cacti.

Subspecies

*''Melocactus azureus'' subsp. ''ferreophilus'' (Buining & Brederoo) N.P.Taylor Melocactus azureus 2e.jpg Melocactus azureus.jpg Melocactus azureus 1e.jpg

References

Endemic flora of Brazil azureus Vulnerable plants Taxonomy articles created by Polbot {{Cactus-stub