I was out exploring the RSPB nature reserve near Newport this weekend and found a patch of waste ground under a pylon which had a few interesting little plants growing amongst rocks that were probably clinker from the old power station. Not a lot was growing there but you can see rabbit fur stuck to the plant in the photo so the poor soil probably isn't the only reason. We've had a very dry spring though so everything was very stunted.
The reason for my question was that I found this small plant with fleshy tri-lobed leaves that reminded me of a saxifrage. Googling ''succulent saxifrage' was no use but I eventually tracked it down as Saxifraga tridactylites, the rue-leaved saxifrage. Apparently it's not a succulent but does have fleshy leaves and I probably have succulent plants that have less flesh to their leaves. It just made me curious where the line is drawn.
Ohhh, there's no definite limit IMHO. It's a question to ask to high-flying botanists (if you think they know). They get off easily by using vague terms like fleshy or sub-succulent. Most (and I mean almost all) plants have succulent tissue at least at a certain stage of their existence. Is the watermellon a succulent plant? I guess not - but the mellon contains almost entirely water. Its thought is to allow the seeds to germinate with plenty of water available. It's a complicated question...
A succulent is something that is still alive when you return from a long holiday in summer.
As for Melons I think the water is to attract seed dispersing animals that will poo the seeds out undamaged further away.
