I got the Old Man in mid-late 1980s, he was 3 inches tall. He lived in a pot, growing to a foot tall
In 1993 I move to the High Desert of Arizona, exactly 3300 ft above sea level. I transplanted him in the fall of 1993.
He's 31 years in the ground. He has full sun, survived 24 inches of snow, 60+mph straight line wind and from 20° F to over 130° F. He thrives.
I hadn't really looked, but today the original arm is feet tall. His tallest arm is well over 4 feet.
The pictures are as he stands today. A few arms are shedding and appear to be wooding. He's healthy as he can be. He began blooming last month and one arm has a full bloom as taken last night, Friday 18 May, '24. They're dying back today.
If you grow them I've attached mature seed pod photos. They're not ready to harvest until the are 12-20mm in diameter and black. The Pod is open so, tilt the bloom down to harvest.
The needles are strong enough to sew with. They have went through the sidewall of a new tire. The hair was harvested by indigenous of his home area and woven into clothes and hats. It gives silk a good run in tensil strength.
I have seen them in their natural habitat. My Old Man looks just like the cactus I saw in the foothills of the Andes.