I first noticed it for its heady perfume that filled the air. I couldn't work out where it was coming from - there were witch hazels around, but it was sweeter than that. Then the ranger who was showing me around put me out of my misery:
"Oh, that's the Osmanthus," he said, grinning a little mischievously. Right, well that was fine, but I couldn't see an osmanthus anywhere. You know them - nice neat medium-sized evergreen shrub, right?
I was actually standing underneath it at the time. This was Osmanthus yunnanensis in full flower - about 30ft tall and scenting the air all around with these lovely little powder-puff white flowers.
There are apparently only 11 left in the wild, and this particular one was brought back by Ernest "Chinese" Wilson in the early 20th century. It's not that difficult to get hold of these days - about ten nurseries around the country stock it. Another one for the 'must-grow-before-I-die' list...