Dave Hill writes
On 4 Feb, 22:12, "Ben Short" wrote:
What you are having if you have 2 stems that come together and join
then seperate and grow away is a "Natural Graft" this can happen with
in nature with plants growing close to each other.

A holly tree in my parents did this on a grand scale - overall effect
was of a large flat trunk with 3 or 4 huge holes right through, then
above about 6 ft the two trunks grew separately again. The parts where
they'd joined was where they'd each thrown a branch in the other's
direction.

But with forsythia I've only ever seen fas...iation (not well at the
moment so don't have the energy to remind myself of the correct term).
Forsythia does it a lot, as does the pink or purple Linaria that seeds
itself over waste ground.
--
Kay