Euphorbia caerulans
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Euphorbia caerulans is a species of the genus spurge ( Euphorbia ) in the family of Euphorbiaceae (Euphorbiaceae). She is endemic to Angola.
description
The succulent Euphorbia caerulans arises from a large, tuberous root and develops many, densely packed, mostly unbranched shoots. The square shoots are up to 7, exceptionally up to 15 centimeters long and 15 to 20 millimeters thick. On the wavy, notched edges there are protruding warts at a distance of 15 millimeters from each other. The triangular thorn shields stand individually, they are initially brown and soon turn gray. Two spines up to 5 millimeters in length and two stipple spines up to 4.5 millimeters in length are formed. The plant is usually leafless; the tiny, succulent scale leaves are shed almost immediately.
The inflorescence consists of single and simple cymes , which stand on stems 2.5 millimeters long. The three cyathia reach about 5 millimeters in diameter, the middle ones are male, the two on the sides bisexual. The five (rarely four) elliptical nectar glands are colored yellow and butt against each other. The bluntly lobed fruit is sessile and is about 4 millimeters in size. It contains the seeds, about 2 millimeters in size, which are covered with warts.
Spread and endangerment
Euphorbia caerulans is common in the southwest of Angola . The species is rarely endemic to the eastern lower Karoo ( Succulent Karoo ) and is almost only given from the Planalto da Humpata plateau. According to the IUCN , its status is indicated as “Indeterminate” (I), which means that the species is presumably endangered, but not enough data are available to estimate the exact degree of endangerment. Like many succulents, it is listed in Appendix II of the Washington Convention on Endangered Species , which means that commercial trade is only possible with a safety assessment by the exporting state.
Taxonomy and systematics
The species was first described in 1898 by Ferdinand Albin Pax . A synonym for this species is Euphorbia coerulans hort., The original spelling cærulans (with ligature ) is differently transcribed as caerulans or incorrectly as coerulans . Euphorbia caerulans is assigned to the subgenus and the section Euphorbia within the genus Euphorbia , of which approximately 340, mostly succulent species are morphologically characterized by the possession of thorn shields. The Tetracanthae section , which was previously established by Pax himself for the Namibian species and to which the species was traditionally assigned, was maintained by Susan Carter in 1994, it is mostly no longer recognized today.
swell
- Urs Eggli (ed.): Succulent lexicon. Dicotyledons (dicotyledons) . Eugen Ulmer, Stuttgart 2002, ISBN 3-8001-3915-4 , pp. 125 .
- LC Leach (1976): Euphorbia (Tetracanthae) in Angola and northern Kaokoland. Dinteria 12: 1-35.
- Euphorbia cærulans Pax Flora of Tropical Africa, Vol 6, Part 1, page 441, (1913) Author: (By JG Baker, with additions by CH Wright.) Digitally at JSTOR Global Plants.
Individual evidence
- ↑ Kerry S. Walter, Harriet J. Gillett (editors): 1997 IUCN Red List of Threatened Plants. IUCN World Conservation Union, Gland and Cambridge 1998. ISBN 2-8317-0238-X , at page 265.
- ↑ Bulletin de l'Herbier Boissier Volume 6, p. 739. 1898 ( online )
- ^ Brian L. Dorsey, Thomas Haevermans, Xavier Aubriot, Jeffery J. Morawetz, Ricarda Riina, Victor W. Steinmann, Paul E. Berry (2013): Phylogenetics, morphological evolution, and classification of Euphorbia subgenus Euphorbia. Taxon 62 (2: 291-315.
- ^ Susan Carter (1994): A Preliminary Classification of Euphorbia Subgenus Euphorbia. Annals of the Missouri Botanical Garden 81 (2): 368-379.
Web links
- Location photos of the kind at senckenberg.de
- Herbarium document of Art
