Despite no sun...

[Chris43]

I've been away in Germany for 5 days and got back to the cool and dull summer continuing. At leats down here we haven't had the extreme wetness of some parts.
But despite the lack of sun, and greenhouse temperatures barely breaking the 22C level, two of my Mamms were showing new flowers.

This Mammillaria maritima, though still only about 10 cm tall, has produced its second flower, this year being the first time it has flowered.

[img]http://www.woodedge.co.uk/Photos/Small/PICT5908.jpg[/img]

and Mammillaria mazatlanensis is opening its buds nicely.

[img]http://www.woodedge.co.uk/Photos/Small/PICT5909.jpg[/img]

[saxocactus]

Lovely - I have no sun here either (east yorks) and two have flowered today.

[Vic]

Nice for it to flower at such a small size Chris - no sign of buds on mine.

[iann]

They must have given up waiting for nice weather and decided to get on with the business of looking good

[countrydudeuk]

Beautiful flowers there. It's strange because my Mamm. bocasana multilanata has produced some new flower buds since the weather turned cooler and more wet too. Just need some sun to make them open now!

[Trevor]

That maritima looks like a Cochemia to me
Sorry, I'm still living in the late 80's cactuswise... and why that asymmetrical non-mamm looking flower isn't enough to break it away from the Mamm's is beyond me....

[Chris43]

It certainly is a Cochemia, Trevor, which still is classed as a subgenus of Mammillaria, although there are a lot of differences I do agree.
The DNA assessments by Wallace and Butterworth seem to suggest that a general reassessment is overdue, but I think there are just too many difficulties with species that don't quite fit. They say "The phylogeny presented in this study suggests that in spite of unique gross morphology, the recognition of Cochemiea at a rank equal to or higher than series would render paraphyletic Hunt?s circumscription of series Ancistracanthae." But then go on to also say that their grouping which included the Ancistracanthae and Cochemia also included members of Coryphantha, Escobaria and Pelecyphora, which they concluded showed paraphyly within Mammillaria. It also very clearly showed that Ortegocactus madougalii was in most likelihood better placed within Mammillaria than anywhere else.

I had to look uop what paraphyly actually meant - it describes a group that contains its most recent common ancestor, but doesn't include all the descendants of that ancestor.

Confused? I certainly am!! So we can end up with plants having similar DNA characteristics, but in different genera, depending on what? other characteristics? and if so which ones?

Is it just me not understanding? (very likely!!) or is there a bit of a mess here, which the DNA analyses have raised, and for which some better framework is needed??

Ugh.....I'll stick to Hunt and Luthy for now....

[iann]

I'll attempt a translation. Paraphyletic means that the grouping of plants are all related to eachother but that other plants not included in the grouping are also related roughly as closely or more closely. The implication is that a "proper" grouping would be extended to include those other plants.

So the whole thing says that the Cochemiea grouping is closely related to core Mammillaria plants but no more closely than some Coryphanthas, Escobarias, and Pelecyphora species. Also Ortegocactus is similarly closely related to the core Mammillarias.

They refer to the morphological differences (difference in outward appearance) between some of these related plants. "Old school" taxonomists essentially followed the principle of anything that looked different got a different name, sometimes regardless of known relationships, often because there was no real information about which plants were actually related. More detailed research, and especially DNA studies, give data about actual relationships between plants but often this shows that plants with completely different appearances are related and similar-looking plants are not. Creating species and genus groupings of plants with incompatible appearances is resisted by many people

[Trevor]

It's all too hard Chris... after a while I think you just kind of know a name for a plant - may not be technically correct on any given day, but it's enough to get the idea across !!

So if the group (paraphyly) contains the most recent ancestor, but not all the descendants of that ancestor - I wonder what was the key factor that took those particular descendants out of the group ....or for that matter retained the original descendant in the group....

okay, now my head hurts...

[Chris43]

Yes, Trevor, mine too.... Obviously wrongly I had hoped that DNA stuff would produce clarity. It doesn't seem to have done so, or at least not yet, although it has given some valuable insights into the relationships.

Ian, your explanation was very helpful, thanks. It seems to me that an eventual outcome could be a redefinition of what we mean by "genus", and that we end up with either fewer of them, or more, maybe something more akin to the muliplicity of genera used by Backeberg.

It's an interesting intellectual conundrum, and one that for interest's sake I shall follow, but at the end of the day, it doesn't really matter whether its M. maritima or Cochemia maritima, it's the plant that matters.