Drosera subg. Thelocalyx
Encyclopedia
Drosera subg. Thelocalyx is a subgenus
of two species
in the genus Drosera. Both species appear to be very similar and are often confused in cultivation; both have small leaves arranged in a rosette
and are annual plant
s. Their distributions do not overlap, however, with D. burmannii
in Southeast Asia
and Australia
and D. sessilifolia
in Brazil
, Guyana
, and Venezuela
.
Subgenus Thelocalyx was first described by Jules Émile Planchon
in 1848 and was later moved to the rank of subgenus
in 1891 by Carl Georg Oscar Drude
. It was later moved back to sectional rank by Rüdiger Seine and Wilhelm Barthlott
in 1994. In 1996, Jan Schlauer revised the infrageneric taxonomy and supported the subgeneric rank, citing the pentamerous gynoecium
and suggesting that the two species are relatively primitive with respect to other species in the genus.
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
of two 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...
in the genus Drosera. Both species appear to be very similar and are often confused in cultivation; both have small leaves arranged in a rosette
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...
and are annual plant
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
s. Their distributions do not overlap, however, with D. burmannii
Drosera burmannii
Drosera burmannii, the tropical sundew, is a small, compact species in the carnivorous plant genus Drosera. It normally spans only in diameter. It is one of the fastest trapping sundews as well, and its leaves can curl around an insect in only a few seconds, compared to the minutes or hours it...
in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and D. sessilifolia
Drosera sessilifolia
Drosera sessilifolia is a species in the carnivorous plant genus Drosera that is native to Brazil, Guyana, and Venezuela and grows in sandy or gravelly soils in seasonal seepages where a thin film of water collects. It produces a rosette of small, wedge-shaped to round carnivorous leaves that are...
in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
, and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
.
Subgenus Thelocalyx was first described by Jules Émile Planchon
Jules Émile Planchon
Jules Émile Planchon was a French botanist born in Ganges, Hérault.-Biography:After receiving his Doctorate of Science at the University of Montpellier in 1844, he worked for a while at the Royal Botanical Gardens in London, and for a few years was a teacher in Nancy and Ghent...
in 1848 and was later moved to the rank of subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
in 1891 by Carl Georg Oscar Drude
Carl Georg Oscar Drude
Carl Georg Oscar Drude was a German botanist.- References :...
. It was later moved back to sectional rank by Rüdiger Seine and Wilhelm Barthlott
Wilhelm Barthlott
Wilhelm Barthlott is German botanist and the head of the Nees-Institute for Biodiversity of Plants and director of the Botanical Gardens of the University of Bonn.- External links :*...
in 1994. In 1996, Jan Schlauer revised the infrageneric taxonomy and supported the subgeneric rank, citing the pentamerous gynoecium
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
and suggesting that the two species are relatively primitive with respect to other species in the genus.