The Garden Community for Garden Lovers

Cactus or not cactus ... that is the question

hywel

By hywel

27 comments


I’ve noticed when I buy succulent plants, they are often labelled ‘cactus’ even when they are not.
And I also notice many people on this site, call all succulent plants ‘cacti’

It’s like saying tulips are daffodils – just because they all grow from bulbs …
So I thought I’d make a blog to show what a cactus really is – because they are not just any succulent plants – they have certain characteristics

……………………………………………………………………..

1
Cacti have SUCCULENT STEMS, which can be round or cylindrical or columnar ….

Or they can be formed of flattened jointed pads

But it is always the STEM that is succulent
……………………………………………………………………..

2
They haven’t got leaves, but they’ve got spines that arise from small pin-cushion-like structures, called AREOLES
as you can see from the next photo ….

……………………………………………………………………..

3
The flowers arise from the areoles.
They are FUNNEL LIKE in structure, and very showy

……………………………………………………………………..

4
The fruit always forms a BERRY ……

……………………………………………………………………..

So these are NOT cacti …

They’ve got succulent leaves – they are Haworthias and Crassulas

And these are not cacti either …..

Although they do look similar ….
But they are Euphorbias

They’ve got that white characteristic sap
And they’ve got small green flowers that are always seen in Euphorbias …
You can see them in the next photo ….

Not a bit like the proper cactus flowers are they …

The spiny ones haven’t got areoles, but the spines arise straight out of the stem …
You can compare the two next photos …

Above is a Euphorbia – no areoles
Below is a cactus – with areoles

……………………………………………………………………..

I hope I haven’t made this blog too technical. It’s only meant as a bit of information :o)
But maybe now you can see that all succulent plants do not belong to the cactus family

Yet there will still be people who continue to make the mistake …. ;o)

More blog posts by hywel

Previous post: More Fuchsia Inspiration

Next post: A New Tomato Variety



Comments

 

great blog and well explained hywel, i must say i have got some confused but most i do know the difference, but will probably still make mistakes, thanx for this :o)) x

29 Nov, 2011

 

It's easy to confuse them Sandra ... Don't worry. It's just an explanation :o) x

29 Nov, 2011

 

You had me rushing back to my photos page to check whether OH has Cactus or not. Still not sure. He can check it out himself later on. It never ceases to amze me how much we learn on GOY. Thank you for taking the time to explain so well.

29 Nov, 2011

 

I bought a cactus today from Morrisons - Christmas Cactus - it sits beside me on desk :)))) The pink flowers are similar to the sempervivums on one of the pics - they're great additions - lovely pics

29 Nov, 2011

 

Generally, Scotsgran, if they've got leaves, they are not cacti
Thanks for reading my blog, and your comment.

29 Nov, 2011

 

Thanks Paul. Christmas cacti are very pretty

29 Nov, 2011

 

absolutely brilliant. clear text and photos. not overly technical either. thanks hywel

29 Nov, 2011

 

I have a question on Christmas Cacti - do they have to be kept moist ? Label states this - but I thought cacti didn't need much ? just don't want to kill it

29 Nov, 2011

 

Thank you Seaburngirl

Paul, they have to be kept moist when in flower, like all other plants.
They need a dryish dormant period to bring them into flower, (usually late summer / autumn) but then water normally after the buds begin to appear. Also give them a feed now and then.
Desert cacti can stand droughts, but these are from tropical rain forests

29 Nov, 2011

 

Thanks Hywel :))))

29 Nov, 2011

 

y w ...

29 Nov, 2011

 

very interesting, thanks hywel

29 Nov, 2011

 

Thanks from me as well - I thought I was ok recognising those two but still learnt a lot:) nice of you sharing your knowledge with us:)

29 Nov, 2011

 

Useful blog, Hywel ..
explained well :o)

29 Nov, 2011

 

A blog I'll refer to in the future - very informative thanks.

29 Nov, 2011

 

Well done, Hywel, for writing such an informative blog! I liked it very much, you made the explanations clear & with the help of the photos there is really no "excuse" for people calling succulents "cacti" nor for calling Cacti "succulents" any more! :-))

I've added it to my favourites for future reference!

29 Nov, 2011

 

Would it be rain that triggers cacti to flower in the wild? That would explain why they need to be watered when in flower and then allowed to go dry again

29 Nov, 2011

 

Great blog Hywel and very imformative, I have never known the difference so really appreciate the time you have taken to explain, added to favs...

29 Nov, 2011

 

Very interesting Hywel, think I am one of those that always make that mistake! I have learnt something today. Thank you.

29 Nov, 2011

 

Great blog Hywel, really interesting! I'm putting it on my favs so I remember who's who! :-)

30 Nov, 2011

 

Very nicely explained. How do you make them flower so profusely ? Is their dormancy a key?

30 Nov, 2011

 

Blimey Hywel, I've learnt so much from reading your brilliant blog. I shall have to print it out and translate what you've posted and show it to my neighbour Ottavia who loves cacti....

30 Nov, 2011

 

Thank you all for reading my blog. I'm pleased so many people found it interesting

Andrew I think rain (or at least some moisture, maybe in the form of dew etc) after a dormant period may help cacti flower in the wild. I try to give them those conditions at home, to get them flowering.
But also I think their age must be taken into account - some will not flower until they are so many years old. Also the amount of light will have an effect I believe.

Mochiseki I think the dormancy plays a part in geting them to flower. It's like all plants really - they need a resting period. I keep them cool and dry during winter. I get varying degrees of success. Sometimes they flower well, sometimes not ...

30 Nov, 2011

 

Thanks Hywel have added your blog to favourites for future reference. It was the Euphorbia ones that threw me. Thanks for the info.

30 Nov, 2011

 

Lovely blog Hywel :)

1 Dec, 2011

 

Wow, I think I will have to come back again to check all this information out. Very interesting, thank you, Hywel, you certainly can learn a lot on GoY.

2 Dec, 2011

 

Hi Hywel, When we were at the Eden project last year i posed the Cacti flowering question with the chap in the desert house, his explanation was that when plants were at the right age and size they (Eden) placed them in front of an electric fan for a few days, in 85% of cases they flowered shortly after. He reckoned this could be because at certain times in the Desert it gets very very windy and allows seeds to be scattered ?
Please note i have no idea if this is true.

1 Jan, 2012

Add a comment

Featured on

Recent posts by hywel

Members who like this blog

  • Gardening with friends since
    1 Apr, 2009

  • Gardening with friends since
    6 Jun, 2010

  • Gardening with friends since
    31 Oct, 2010

  • Gardening with friends since
    10 Sep, 2010

  • Gardening with friends since
    7 Sep, 2010

  • Gardening with friends since
    14 Aug, 2008

  • Gardening with friends since
    4 Apr, 2009

  • Gardening with friends since
    29 Apr, 2010

  • Gardening with friends since
    22 Oct, 2008

  • Gardening with friends since
    9 Aug, 2009

  • Gardening with friends since
    8 Apr, 2010

  • Gardening with friends since
    13 Feb, 2011

  • Gardening with friends since
    4 Oct, 2011

  • Gardening with friends since
    7 Jun, 2010

  • Gardening with friends since
    11 Apr, 2008

  • Gardening with friends since
    5 May, 2010

  • Gardening with friends since
    9 Jul, 2010

  • Gardening with friends since
    27 Sep, 2008

  • Gardening with friends since
    26 Feb, 2008

  • Gardening with friends since
    18 Sep, 2008

  • Gardening with friends since
    1 Mar, 2008