Cactus ID for an old plant

[sthh]

Got this more than 17 years ago. It was spineless then and had white flecks, and had only 4 ribs, but it grew to slightly more than 1 metres tall, and developed 6 ribs and turned green now. It is leaning against the window because it cannot support itself anymore, unlike a normal tall growing cactus. I believed I bought a astrophytum myriostigma, but I don't really know. Can anyone ID it? Taken some pictures, including one where it starts developing ribs.

[Ancientforest]

Looks like a stenocereus, which species I'm not sure. Most of them get massive:
http://www.cactiguide.com/cactus/?genus=stenocereus

[sthh]

Looks like a stenocereus, which species I'm not sure. Most of them get massive:
http://www.cactiguide.com/cactus/?genus=stenocereus

Thank you Ancientforest for the suggestion. I will go look it up.

[sthh]

The problem is that I have a vague memory that I bought a astrophytum myriostigma looking more like http://www.cactusmuseum.com/images/astr ... stigma.jpg" onclick="window.open(this.href);return false; (pic from internet)i. Anyone has an old and tall astrophytum myriostigma I can look at?

[george76904]

Don't have a picture of an old myriostigma, but Iam in solid agreement with Ancientforest about it being a stenocereus. It is definitely not an astrophytum.

[DaveW]

Far too thin and columnar to be an Astrophytum. As a seedling it may have been mistaken for one of the nude Astrophytum's:-

http://www.cactus-art.biz/schede/ASTROP ... _nudum.htm" onclick="window.open(this.href);return false;

But this would have been obviously wrong as it grew taller.

See:-

http://cactofilos.com/tag/habitat-2/" onclick="window.open(this.href);return false;

http://www.cactus-art.biz/schede/ASTROP ... umnare.htm" onclick="window.open(this.href);return false;

The taller growing more columnar Astrophytum is A. ornatum, often believed to be an ancient hybrid between an Astrophytum and Ferocactus. But it is much stouter and shorter than your Cereus.

http://www.flickriver.com/photos/jesusc ... 965397621/" onclick="window.open(this.href);return false;

[greenknight]

Also, on old Astrophytum myriostigma plants the areoles become larger and more woolly, as shown here - http://cactus-art.biz/schede/ASTROPHYTU ... stigma.htm" onclick="window.open(this.href);return false;

Stenocereus looks much more likely to me.

[sthh]

Thank you all for the help. Hope my plant will flower and bear fruits soon, as I understand that the fruits are edible.

[7george]

This can be even a Myrtillocactus. At room conditions with not much sun, growing in the North somewhere... Got green because the tip is closer to the ceiling. That is my suggestion. Let us see some flowers, if in bloom.