Solved Penstemon conundrum

I've had a clump of Penstemon 'Garnet' in a border for 15-20yrs.
Where a stem touches the soil it usually roots and so the clump has spread. Probably the toughest of all Penstemon so it does very well.
A very harsh winter 2 yrs ago and I lost 40-50 penstemon of several varieties dotted around my garden - very saddening.
Even the clumps of Garnet seemed to be lost.
But last year I spotted tiny green shoots on some stems on Garnet.
It didn't flower last year, but has this year.

What is confusing me though is that one clump now has different colour flowers, the flowers are larger and the plant much taller....
You can see the new Garnet in the middle and the usual colour Garnet to the right.
The leaves on the stems are identical

Any thoughts as to what's happened?


The normal Garnet


The taller new version that's appeared with larger almost coral colour flowers

 

A random seedling?

 

Thanks @Palustris
I don't think it's a seedling as I can see that it is a rooted stem from the main plant which is why I can't understand how it looks so different.
I've never found a seedling in that area in all the years I've had them, so I assume they're sterile - which may be a wrong assumption.
I'm wondering if it's a sport.
It's an unusual colour and not one I've seen before in a penstemon, so I'll take some cuttings.

I just wondered if anyone else had had something similar happen.

 

I suggested seedling as I grew some from seed and one of them is a nice new, to me, colour.
Some of the hybrids are sterile I agree.
I have a P. Hidcote which has thrown a stem where the pink is reduced to a small bit at the base of the flower. It may revert later in the season though.

 

Thanks - How interesting, I've not noticed penstemon seed for sale before so it's something I'll try.
And there was me thinking I had something a bit special
I'll take some cuttings and see if I can get a few more plants.

 

The seeds I sowed were from P. Apple Blossom. Some of mine set seed quite readily. I really ought to dead head them I suppose.
This is the one from seed which is new to me.

 

What a lovely colour!
I'm definitely going to try them from seed next year - thanks for the tip