Discocactus horstii?

[HeidiL]

Is this Discocactus horstii?

When I look at photos of the discocatus hortii theu seem to have more ribs than mine, so I am not sure.

Ps. I tried to use the advanced search, but was not able to make it function. I tried it both on Google Chrome and Internet Explorer.

Thanks in advance

Heidi in Norway

[Brontosaurus]

It looks very much like a Echinopsis subdenudata to my eye.

[greenknight]

Agreed.

[HeidiL]

Now I am a bit confused. Who do you agree with?

[cactushobbyman]

In your picture is Echinopsis subdenudata.

[HeidiL]

Thanks to all of you.

I am impressed by your knowledge.

Heidi in Norway

[greenknight]

I was agreeing that it's Echinopsis subdenudata.

[Aiko]

At least definately not a Discocactus. I assume you got your plant at a garden centre? I would be extremely surprised if they would have a Discocatus in their collection of plants, especially in a country with cold temperatures.

[Cactus John]

Don't be too disappointed that it's not a Discocactus. It looks like yours has a flower bud just forming on the righ-hand side so you can look forward to a lovey flower like mine.

Echinopsis subdenudata - 25th May 2017

IMG_1817.JPG (71.55 KiB) Viewed 2803 times

[HeidiL]

So beautyful!

Lucky me who has two pots with this wonderful cacti, and there are flower buds on both of them.

Thanks for showing me the flower. I look forward to see it in my house.

Heidi in Norway

[DaveW]

Certainly an Echinopsis not a Discocactus. Discocacti are rather touchy and don't like cold in the UK so need to be kept warmer in winter, and the same in Norway being Brazilian species. D. horstii is the most commonly grown. A quote on D. horsti cultivation from the link below.

"Cultivation and Propagation: It is rather difficult to grow and frost tender, should be kept at above 15° C if grown on its own roots (8°C if grafted) need full sun or afternoon shade. Young seedlings are generally grafted because they are slow growing and very rot prone when kept on their own roots and though they can’t endure long stretches of total dryness, too much water will rot them, as their weak root systems tend to be inefficient at sucking up water from wet soil. They generally resent being repotted and can take a long time to establish."

http://www.llifle.com/Encyclopedia/CACT ... us_horstii

Echinopsis are much easier to grow only requiring normal cactus cultivation and still have spectacular flowers.

[sabotenmen]

[quote="DaveW"]Certainly an Echinopsis not a Discocactus. Discocacti are rather touchy and don't like cold in the UK so need to be kept warmer in winter, and the same in Norway being Brazilian species. D. horstii is the most commonly grown.
Are you sure horstii is the most commonly grown Discocactus, Dave? Here in Japan ,when I see Discocactus ,they're usually zehntneri .When I see a horstii (hardly ever), it's an ugly ,obviously grafted and overpriced (8000 yen,85 euro) specimen.Zehntneri is around 1000 yen.....

[sabotenmen]

Echinopsis are much easier to grow only requiring normal cactus cultivation and still have spectacular flowers.

True, but when grown outside,watch out for spider mites,as they are sensitive to them. I lost my whole collection of Echinopsis because of spider mites....

[DaveW]

In the UK D. horstii is the most common. Probably the usual case that dealers only propagate the most attractive smaller species that sell Sabotenmen. Also with our climate in the UK it costs more to raise plants that need more heat in winter. This constraint does not apply in warmer climates and then Melocacti and other tropical cacti in nurseries will be common. I would think virtually all Melocacti you find in British nurseries or garden centres are imported. I remember years ago going to a British cactus nursery at the end of a particularly cold winter and the owner telling us if the cold snap continued for more than a couple more weeks he would have to switch the heating off in the sales greenhouse and let the plants die if needs be, because the cost of the additional heating would then exceed the cost he could sell the plants for, therefore he would have to cut his losses.

Many plants are introduced and become available but then gradually disappear from dealers lists as they are either commercially difficult to produce for sale at a reasonable price, or rather go out of fashion with the more attractive forms only still being grown.

In the UK you will find the purple flowered Notocactus uebelmannianus (Parodia werneri) easily, but the yellow flowered form N. uebelmannianus v. flaviflorus, which was initially equally available is now rarely grown by the trade. Also N. arachnites and N. crassigibbus, introduced at the same time have largely disappeared from dealers lists. The same with Gymnocalycium horstii. The more saleable G bueneckeri form with the coloured flower is easier to obtain than G. horstii with the less attractive (to most) white flower. In fact the "horstii's" on sale with the duller body and pink flower are in fact G. bueneckeri, or G. horstii v. buenekeri and not the original species the shiny bodied white flowered G. horstii.

One of the reasons for collectors to learn to grow from seed rather than always rely on ready grown plants being available, since when these species disappear from the dealers lists as plants they are often still available from seedsmen as seeds. Just not a commercial proposition to raise as plants by dealers due to limited demand and more saleable easily raised species. In fact you are more likely to be able to pick them up as plants from other collectors who have raised them from seed themselves and have spares available. We have to remember that nurserymen are there to earn a living by selling the plants that are the most profitable for them. The niche market for more difficult or slower growing plants, even at very high prices is still very limited.

[sabotenmen]

I want to thank you for the time you took to write this interesting article, Dave.