Cintia springtime?

[MikeT]

I'm sure this is earlier than usual flowering time. In previous years there have been a few flowers in succession, only 1 or 2 open at a time. This year a crop of buds appeared together. 3 open now, it seems a new flower opens every couple of days to join the earlier ones.

The plant stem is shrivelling somewhat, but only 2-3 months before I let it have some water.

[Eveandrea]

You are not complaining, I'm sure
It would be interesting to understand, what changed this year. Different temps and light in Summer or Autumn? Maybe the plant felt theartened to death by shrivelling?

[Les.Needham]

The genus Cintia sent me skuttling to my books, where I find it under Rebutia - R. cintia to be exact - where it is referred to as a curious neotenous plant. That sent me skuttling back to the books again. Neotenous? Neotenous? Apparantly that means that it retains immature characteristics in its adult form. Seeing as you have the plant do you have any idea what this may mean specifically? Also noted is that it is an ''almost geophytic alpine''. This is hardly surprising, considering that it grows at 4000 metres!!

[DaveW]

Whether it should be under Rebutia is a matter of opinion as a lot of the lumped Lexicon "Rebutias" will have to be split up again due to DNA Sequencing information showing they belong to different lines of evolution. Ritz et al say:-

"Our results suggest that Rebutia s.l. and Echinopsis s.l. are not monophyletic and that Sulcorebutia, Weingartia, and Cintia should be united into one genus."

"Current classification of Cactaceae is based mainly on morphology. A group of cactus taxonomists within the International Organization for Succulent Plant Study has tried to achieve a consensus between the widely varying views concerning the number of genera and species within the family (e.g., Backeberg, 1977; Hunt, 2006). However, the high level of convergence within Cactaceae does not allow for reliable morphology-based classification."

http://www.amjbot.org/content/94/8/1321.full.pdf

Knize listed three species just because they were from different localities. I had two of the "names" and they are impossible to tell apart:-

http://www.english.sulcopassion.be/0051_2007.pdf

http://www.cactus-art.biz/schede/CINTIA ... knizei.htm

DaveW

[David Neville]

Whether it should be under Rebutia is a matter of opinion as a lot of the lumped Lexicon "Rebutias" will have to be split up again due to DNA Sequencing information

"Have to be"? There are no cactus police to enforce this!

There is lots of speculation about what could or should be recognized in an updated Lexicon ............. but there were some big surprises last time, and if anybody thinks that a revised edition is likely to be any less radical then they might have a shock!

[DaveW]

"Will have to be split up"??

True, the fact there are no cactus police works both ways David. The IOS Committee will have little further credibility or following in the botanical world if it clings on to its morphological conclusions now proved wrong by other forms of science.

Also if radical revisions need to be made to the Lexicon, which was a pretty expensive book in the first place, there will be less confidence put on any revisions made by the same committee rather than the need to form a new committee drawn from wider scientific disciplines. Plus as we were promised updates rather than a complete rewrite, meaning the same expense all over again, less purchasers for it in future.

Nobody expects any classification to be perfect, but you only have to look at the dates when most of the DNA information was published to see it should have reached the committee before the Lexicon was published in its present form. It rather looks as if the committee decided to hang on to its preconceived ideas in face of evidence to the contrary. I hope if a new, New Cactus Lexicon is published it will have used all the scientific evidence available to date, rather than just a preconceived morphological classification from conventional botanists?

Unfortunately David, many of the surprises last time (the lumping) have proved erroneous, lets hope the new surprises are not just as wide of the mark.

DaveW

[MikeT]

Although the label of the plant pictured reads "Rebutia cintia", as far as I'm concerned it doesn't look like a Rebutia, the flowers don't look like Rebutia flowers, and they arise from the plant apex, unlike any other Rebutia I've ever seen. Hence a post which could have been referring either to "Rebutia cintia" or "Cintia knizei". Just because I wrote them doesn't mean I have to believe my plant labels

[Lithos]

Well said Mike - I fear posting anything South American on this forum, as it will be over analysed. I grow a few 'Thelocephala' - but don't want a rant on nomenclature all the time. What are they now Dave?

[Phil_SK]

Awww, that's half the fun of S. American cacti. You get a new batch of plants every month without spending anything!

[Lithos]

A new batch every month! crikey, is Knacker Knize still flogging stuff - oh hang on you said they are free, can't be him.