31. January 2011
Posted by Wölfchen under Some science
| Tags: Ceropegia
Leave a Comment
How many distinct genera are actually included in the genus Ceropegia?
More than one 😉 , see here.:
Ceropegia includes more than 200 species distributed in the Old World ranging from the Canary Islands to Australia. In India, there are about 50 species described on a morphological basis as belonging to Ceropegia, and most of them are endemic to the Western Ghats. To investigate evolutionary relationships among Indian Ceropegia taxa and their allies, a phylogenetic analysis was conducted to include 31 Indian taxa of Ceropegia and Brachystelma and their congeners from other geographical regions using nuclear ribosomal internal transcribed spacer (ITS) and three noncoding chloroplast DNA (cpDNA) sequences, including intergenic spacers trnT-L and trnL-F, and trnL intron. The Western Ghats Ceropegia species were found to be most closely related to Indian Brachystelma, with the two genera being placed sister to each other in the ITS phylogeny or with the Brachystelma clade nested within one of the two subclades of Indian Ceropegia in the cpDNA phylogeny. In contrast, Ceropegia species from other regions and African Brachystelma all formed separate clades basal to the Indian Ceropegia–Brachystelma clade. Thus, it can be concluded that the classical morphology-based delineation of the two genera needs revision to reflect their phylogenetic relationships, which are more in accordance with their geographical origin than with morphology.
– Siddharthan Surveswaran; Mayur Y. Kamble; Shrirang R. Yadav; Mei Sun: Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. Plant Systematics and Evolution 281(1-4): 51-63. 2009
In short, the genus Ceropegia is in fact not a single genus, and will probably be split into several distinct genera some day.
31. January 2011
What happens when the dormancy period is neglected?
Well, actually not quite much. The plants go on with growing and flowering, and it seems to be okay for them.
But in fact it isn’t!
The plants which are dormant during a period of time in the wild, should get such a ‘time-out’ in cultivation too. They use this time to regenerate, and the grower can use this time for repotting and for removing of old substrate or dead roots etc..
See what happens first, when You miss the right time to give Your plants colder and drier conditions.:
Not only does it look harmless, it looks quite beautiful too. But when the actual growing season starts, the plants show the first signs for inanition – and this doesn’t neighter look harmless nor beautiful then. 😦
25. January 2011
A (definitely) new Ceropegia from Thailand
… and I don’t talk about Ceropegia thailandica.
This spectacular plant is, in my opinion, an up to now completly unknown, new species.
The stems are reddish brown and shortly hirsute throughout.
The leaves are narrowly to broad egg-shaped, dark green, with reddish brown edges, as well as with a short, also reddish brown petiole, and hirsute too.
The quite large flowers appear in a threesome at long stemed cymes. They appear a bit like a mix of the flowers of the two species Ceropegia simonea and Ceropegia spiralis. The bottom and the flower-tube are greenish yellow in colour and are heavily speckled with brown. The petals, which open to large mouths, are lemon-yellow to greenish yellow in colour. The upper parts are yellowish brown in colouration, elongated thread-like and twisted screw-like without beeing united at the end.
This plant grows obviously in grassland.
The plant was found and photographed in the Sai Thong National Park / Chaiyaphum Province / Thailand by Shuichiro Tagane.
Photo: Shuichiro Tagane; by courtesy of Shuichiro Tagane
25. January 2011
A (probably new) Ceropegia species from Cambodia
A strange, and possibly new species was found and photographed in Cambodia by François Sockhom. He showed the plant on his blog at the 31. October 2010.
As far as I know no Ceropegia species was known from Cambodia up to now. But of course several species occur in the neighbouring countries, especially in Thailand.
See also Undetermined Ceropegia from Cambodia
This plant has some similarities to Ceropegia ciliata resp. Ceropegia ensifolia (of which I don’t know the flowers), both from India. It reminds me also on the vignaldiana leaf-form of the Ceropegia bulbosa complex, but it could also be Ceropegia sootepensis.
Actually I have no idea which species this may be, so I’d like to regard it as a new one.
Here is the plant, note the very narrow leaves and the very small flowers.:
A single flower, it looks somewhat similar to the flowers of Ceropegia bulbosa, but seems to lack any cilia at the lobes.
Both photographs taken by François Sockhom; shown here by courtesy of François Sockhom