Desmidorchis
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The genus Desmidorchis belongs to the subfamily of the silk plant family (Asclepiadoideae) in the family of the dog poison plants (Apocynaceae). The flowers of these succulent plants give off an unpleasant odor .
description
Vegetative characteristics
Desmidorchis - species grow as stem succulent , perennial plants . The succulent, 1 to 5 cm wide, blue-green or light-brown, cylindrical stem axes are smooth, hairless, have four sharp edges; they reach heights of growth of 20 to 120 cm and stand together in groups. They contain clear milky juice . The sessile, succulent leaves, which are only 0.5 to 2 mm long, are reduced to egg-shaped scales , and protrude horizontally to a little upwards and fall off quickly; they are fleshy or form spines in Desmidorchis foetida and Desmidorchis speciosa . The stipules are reduced to a few hairs.
Inflorescences and flowers
The terminal, simple, pseudo-gold inflorescences usually contain ten to 80 (in Desmidorchis acutangula up to 200) at most very short-stalked flowers that all open at the same time. The flowers , which smell unpleasantly of manure, are hermaphroditic, radial symmetry , five-fold with a double perianth . The five free sepals are at most the same length as the corolla tube. The five fleshy, 1.5 to 3 cm long petals are flat to bell-shaped between a quarter to half of their length. The edges of the corolla lobes are smooth or ciliate. The inside of the petals is green or yellow over brown to purple, monochrome or mottled purple; the surface can be smooth ( Desmidorchis flava ), warty, wrinkled, papilose ( Desmidorchis foetida , Desmidorchis awdeliana ) or hairy ( Desmidorchis acutangula ). The outside of the petals is green. The "gynostegium" has a very short stalk at most. The secondary crown is divided into staminal and interstaminal secondary crown . The upright pollinia are spherical, egg-shaped or D-shaped. There are two smooth, free, upper carpels . The scar head is white. No nectar is produced.
Fruits and seeds
The follicles , usually in pairs at an angle of 0 to 60 ° to each other, more or less upright, are smooth, slender with a diameter of 6 to 10 mm, ovoid in cross-section, spindle-shaped to pencil-shaped and often quite long at 10 to 15 cm. The light to dark brown seeds are egg-shaped, 5 to 9 mm long, 3 to 6 mm wide. They have pure white flying hairs that are 2.5 to 3.5 cm long.
Chromosome numbers
The chromosome numbers are 2n = 22 (investigated in Desmidorchis foetida and Desmidorchis flava ).
Systematics and distribution
The distribution area extends from North Africa to the Arabian Peninsula and West Africa .
The generic name Desmidorchis became valid for the first time in 1829 by Christian Gottfried Ehrenberg in Linnaea , 4, p. 94 and in 1832 in Abh. Königl. Akad. Wiss. Berlin 1829 , 31, 39 republished. All species were included in the genus Caralluma R.Br. incorporated and 1990 by Michael George Gilbert in Bradleya , 8, 19 in a subgenus Caralluma subg. Desmidorchis (Honorary Officer) MGGilbert posed. The genus Caralluma R.Br. was divided into eight genres by Darrel Charles Herbert Plowes in 1995. The genus Desmidorchis Ehrenb. was reactivated. Type species is Desmidorchis retrospiciens Ehrenb. , today a synonym of Desmidorchis acutangula Decne. For Desmidorchis Ehrenb. there are the synonyms Crenolluma Plowes and Sarcocodon N.E.Br.
The genus Desmidorchis belongs to the Subtribus Stapeliinae from the tribe Ceropegieae in the subfamily Asclepiadoideae within the family of Apocynaceae .
There are about ten to fourteen species of Desmidorchis :
- Desmidorchis adenensis (Deflers) Meve & Liede : It occurs from Yemen to southern Oman.
- Desmidorchis arabica (NEBr.) Meve & Liede : It occurs on the Arabian Peninsula.
- Desmidorchis aucheriana (Decne.) Kuntze : It occurs on the southern Arabian Peninsula.
- Desmidorchis awdeliana (Decne.) Liede & Meve : It occurs in Yemen.
- Desmidorchis edithiae (NEBr.) Plowes : It occurs from eastern Ethiopia to northern Somalia.
- Desmidorchis flava (NEBr.) Meve & Liede : It occurs on the Arabian Peninsula.
- Desmidorchis foetida (EABruce) Plowes : It occurs from Kenya to northern Uganda.
- Desmidorchis impostor Jonkers : The species first described in 2010 occurs in Oman.
- Desmidorchis lavrani (Rauh & Wertel) Meve & Liede : It occurs from southern Yemen to southern Oman.
- Desmidorchis penicillata (Deflers) Plowes : It occurs in northeastern tropical Africa and on the southwest and southern Arabian Peninsula.
- Desmidorchis retrospiciens Ehrenb. (Syn .: Desmidorchis acutangulus Decne. ): It occurs from the Sahara to the southwestern Arabian Peninsula.
- Desmidorchis somalica (NEBr.) Plowes : It occurs in Somalia.
- Desmidorchis speciosa (NEBr.) Plowes : It occurs in northeastern and eastern tropical Africa.
- Desmidorchis tardellii Mosti & Raffaelli : It occurs in Oman.
supporting documents
literature
- Bert Jonkers: On the gender of Desmidorchis. Asklepios, 70, 8th 1997
- Sigrid Liede-Schumann & Ulrich Meve: The Genera of Asclepiadoideae, Secamonoideae and Periplocoideae (Apocynaceae) , 2006: On the genus Desmidorchis - Online at INTKEY databases of the DELTA System . (Section description and systematics)
- Ulrich Meve & Sigrid Liede-Schumann: A molecular phylogeny and generic rearrangement of the stapelioid Ceropegieae (Apocynaceae-Asclepiadoideae.) In Pl. Syst. Evol. , 234, 2002, pp. 171-209.
- Roy Mottram: (1889) Proposal to conserve the name Desmidorchis (Apocynaceae, Asclepiadoideae) with a conserved type. , in Taxon , 58, 2009, pp. 648-649.
- Darrel Charles Herbert Plowes: The nomenclatural status and typification of Desmidorchis Ehrenberg (Stapelieae: Asclepiadaceae). , in Excelsa , 17, 1996, pp. 68-78.
Individual evidence
- ^ Darrel Charles Herbert Plowes: A reclassification of Caralluma R. Brown (Stapelieae: Asclepiadaceae). in Haseltonia , 3, 1995, pp. 49-70.
- ↑ Ulrich Meve & Sigrid Liede-Schumann: A molecular phylogeny and generic rearrangement of the stapelioid Ceropegieae (Apocynaceae-Asclepiadoideae. Pl. Syst. Evol.) , 234, 2002, pp. 171-209.
- ↑ a b c d e f g h i j k l m n Rafaël Govaerts (Ed.): Desmidorchis - World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew. Last accessed on November 7, 2017.
