FTF!!! @ 6:15pm
Not being one to give up easily when there is a FTF to bag, I returned home and did some reading up on Florida horticulture and realised where the cache would be - the item concerned looks VERY different in the UK and so I'd mis-interpreted the hint this morning.
Once back where I thought the cache was, I did an even more thorough search than I did this morning and came up with the cache in no time at all. It was very well hidden, southern California style. I must have had my hands on it this morning and not noticed it - doh!
The cache is very much there and waiting for the next finder.
Now on to the final cache ...