September 2017 Copiapoa tenuissima

[Steve Johnson]

Not sure if it's the largest, but certainly one of the larger Copiapoas. I purchased this lovely specimen from CoronaCactus Nursery in July 2013, and on 9/8 here's the latest from its run of flowers that started back in May:





The tenuissima arrived not long after I installed a new custom built 2-shelf plant bench. The cactus is surrounded by some of its friends in the part of the bench I call "Shady Glen", and shade provided by the top shelf is there to protect scorch-prone plants in the blazing midday heat of summer. And all 3 of my Copiapoas heartily approve -- the week leading up to Labor Day gave the coastal L.A. region a string of daytime highs above the century mark (very unusual!), but not even a hint of scorching was to be found.

Now for a closeup of the tenuissima's post-Labor Day flower:

[DaveW]

Nice plant Steve.

C. tenuissima is in fact one of the smaller Copiapoa's in habitat, as with all the C. humilis types. The largest Copiapoa's are the C. cinerea/haseltoniana types. As with many cultivated plants yours is a lot larger than would be found in habitat where it often grows virtually level with the ground, or even slightly buried. (tenuissima = tenuous - the word - meaning; very thin in diameter)

http://www.cactus-art.biz/schede/COPIAP ... issima.htm

The largest Copiapoa is supposed to be C. haseltoniana ssp. gigantea, some are larger than the picture below which is about 1 meter high.

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Afraid I do not have a picture of C. tenuissima in habitat.

[DaveW]

A picture of my C. tenuissima photographed an hour ago, not as nice a shape as yours Steve. Like yours much larger than would be found in habitat. It came from a friend who died and many of his plants always seemed to grow columnar and single, but always seemed to start to offset when I got them. Plant is about 4" high.

Looking up Ritter's description for C. tenuissima he says:-

"Body in nature flat with the ground, in cultivation semi-globular. Body 2-4cm rarely to 5cm thick" ( = body about 2 inch max diameter in habitat).

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A lot of the Chilean "earth cacti" tend to grow much larger in cultivation and a bit out of character, I have seen Thelocephala lenbckei's 6" high in cultivation, but the largest I saw in habitat was only 2" high and most much smaller than that. I did not manage to get to see C. tenuissima it in habitat, but here is a video of it taken on obviously a much dryer and more typical year than the one in 2015 when I went.

https://www.youtube.com/watch?v=9pPeaSLXbYI

[C And D]

I have a couple old nice plants
This one is messy in a pleasing way to me, lots of dead flowers lingering and seeds spilling off the sides.

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I threw a load of C. laui seeds in our garden a couple years ago and was excited to get some nice sized plants out of it,
but as they aged the spines were very unlike the C. laui parents,
I finally decided that they must be C. laui x tenuissima
This one is a real sweety.

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