''Discocactus'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
cacti
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 Greek ...
. The name comes from the
ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
' (=disc) because of its shape. ''Discocactus'' plants are endemic to southern Brazil, eastern Bolivia, and northern Paraguay. These species are in the risk of extinction in the wild.
Description
The plants have a slightly flattened spherical shape. The
areole
In botany, areoles are small light- to dark-colored bumps on cacti out of which grow clusters of spines. Areoles are important diagnostic features of cacti, and identify them as a family distinct from other succulent plants. Gordon Rowley - W ...
s bear sharp spines. At the apex of the adult plants, there is a wooly
cephalium
Cephalium is a frequently brightly coloured structure of wool and bristle at the growing tip of certain cacti. It is most commonly found on cacti of the genus ''Melocactus'' and can take a number of colours, forms and shapes.
The cephalium will on ...
, white or shaded with yellow or grey. The white nocturnal flowers appear on the sides of the cephalium. The fruits are pink or red and contain black seeds.
Species
All species are listed under Appendix I of
CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
meaning commercial international trade is prohibited and non-commercial international trade is regulated.
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References
Bibliography
* Edward F. Anderson : ''The Cactus Family''. Timber Press: Portland (Oregon), 2001, p. 218-221
* N. L. Britton, J. N. Rose: ''The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family''. Washington, 1920
External links
*
photos on www.AIAPS.org
*
photos on www.cactiguide.com
Trichocereeae
Cacti of South America
Flora of Brazil
Flora of Bolivia
Flora of Paraguay
Cactoideae genera
{{Cactus-stub