This is a cactus that I came across whilst I was last on a visit to the botanic gardens in Sydney. It has everything that I like about cacti-odd looking, relatively easy to care for and have great flowers too.

As the name suggests, it hails from South America, more specifically Uruguay, Brazil and Argentina. Different information on this cactus states that it can reach a maximum height of 6 metres while others say 15 metres, either way, tall enough to make someone feel quite small. This is quite vague but it can have a trunk or not that can reach a diameter of thirty centimetres. This does branch out when mature, often looking like a candelabra.

In colour, the apple cactus is blue-green (helps to reflect heat and light, which is helpful for keeping the cactus cool). When young, it can be glaucous, which means that it is covered in a waxy coating which is either grey, blue or white in colour that helps in water-loss prevention. Another adaption, that a lot of other cacti have too) is that cacti photosynthesise in their stems, which helps to reduce water loss in this process. A further adaption is that CAM photosynthesis is used by this cactus, this differs from the bog standard, normal photosynthesis in that the stomata (gas exchange area of the leaf, usually, but stem in this case) stay closed during the day to prevent water loss and open at night to take in carbon dioxide and then store it. During the day the carbon dioxide is released within the cactus to complete the photosynthesis process. Spines on this cactus also help with water as dew condenses onto them and then drips onto the soil, which water soaks into, giving the cactus a drink.

This is a night flowering cactus that has white flowers, pollinated by bats that come looking for nectar. Flowers reach 20 cm long. These fragrant and showy flowers only last one night are followed by a purple-red (when ripe) berry. These berries are edible, often being made into jams but can also be eaten raw apparently. Seeds are ‘large’ (compared to what, I don’t know) and ovoid and brown in colour.

From what I have read of this particular species of cactus is that it is happy in a range of soils. It prefers full sun and dry air. It also has a habit of becoming a bit of a weed. Here in Australia, the apple cactus has taken to the Queensland climate rather well and the same in other parts of the world with a similar climate.

I do think this cactus looks pretty cool as it looks like a melting candle. I have only seen it in the Sydney botanical gardens and it gets too big to even consider growing at home (which is part of what makes botanical gardens gardens great-you see all sorts of plants that you wouldn’t normally). The only downside side to this is that I’m unlikely to ever see the flowers as they only appear at night.

https://buymeacoffee.com/flatcapgardener

References

All photos are my own.

Https://profiles.ala.org.au/opus/foa/profile/cerus%20uruguayanus

Https://plantnet.rbgsyd.nsw.gov.au

Https://myplantin.com/plant/6835

Https://herbaria.plants.ox.ac.uk