I would not be surprised that guaranitica and microphylla would cross, but the hybrid would be sterile. Guaranitica has crossed with gesneraeflora (Purple Majesty), splendens (Black Night), and cardinalis form of fulgens? (Betsy's Choice). Though the chromosome number of guaranitica differs from the other parent, they still crossed. Microphylla has the same base number as gesneriiflora and fulgens, I believe.

Penny, do you have an image of the red guaranitica you can post?

Rich,
I don't have an image yet. I plan to get a picture of it as soon as it comes back into bloom.

At first I thought it may have crossed with coccinea as I had forgotten about my microphylla. wnile doing some watering and plant clean up the other day I noted that the leaves were actually much smaller than my coccineas and very small compared to the Black & Blue and were shaped more like the microphylla. Last year it bloomed in late summer. I hope it will bloom sooner this year so I don't have to wait that long for a photo.

Penny