The tree for this period of the year in the Ogham tree alphabet is the Rowan or Mountain Ash.
Representing the letter L and the number 2 for the second Lunar Month
It was on a cycle ride last September when I found a Rowan with berries to recognise it and in a good place to photograph about 2½ miles from home.
They are much more common in Wales and Scotland and although we had a couple at the smallholding that got to over 10 feet tall while we were there, they rarely had more than a few berries.
I've never used the berries to make a jelly, mainly because it needs an awful lot of sugar to take away the astringency and I usually had redcurrants anyway. In history it was also used to ward off evil spirits and witches.