I love the black colouring to the base, do they all do this with age? Yes. There are actually four bands of colour on this plant, though you can only really see three in the photograph. The spines are white, grey, brown, black, reading from the top, and the plant itself, of course gets a gradually ...

Lyn wrote:Beautiful bloom Peter :-)

It's not so impressive if you see the whole plant!

Very nice Peter I hope my seedlings look this good in a few years! This one is a foot high! I find my Matucana krahnii overwinters buds, and have had a flower open last week, so not unusual behaviour I think. That is interesting to know, Diane. It may be a characteristic of the genus. I'm hoping Ha...

Rather surprisingly, this was my first flower of the year: It has tried to flower in late Autumn for the past two years. Two years ago it simply aborted the single bud it had produced. Last year it produced two buds which appeared to abort as well - my last sight of them was as contracted little bal...

IanW wrote: You display an alarming amount of arrogance in professing that some of the greatest minds in history are wrong I am not professing that some of the greatest minds in history are wrong. Only that you are wrong. You do not, by the way, seem to know the meaning of the word `axiom'. It is a ...

IanW wrote: it doesn't matter if people disagree on the axioms (those are the things you're incorrectly calling assumptions No. That the number set does not include 0 is not an axiom. It is an assumption ('hypothesis', if you will). Some number sets do include 0. IanW. wrote: providing their exists ...

Ian W wrote: "Well I've already pointed out that you can prove 1 + 1 = 2 with the Peano axioms" I had intended to bow out of this argument, since it seemed to have little to do with cacti or succulents, but as it seems to have started up again... Peano axioms are a tool. They do not prove ...

Depends what species they are. I'd be inclined to reproduce the soil type they expect. I've had good results with Echinomastus seed up to five years old - but fifteen... Even after sowing they seem to come up over a period of a few months to 3+ years and that has been true of new and old[er] seed.

I think I want a rigidissimus. What a beautiful flower! Very good pictures, all of them, as well. I'll echo Wilks's thanks...

I give this one up! The 1 + 1 bit was a squib anyway, put in to tempt you. The real point was the John Stuart Mill example.