Achimenes erecta 'Tiny Red'
I had never seen a diastema other than the pictures of diastema vexans, which honestly isn't that impressive to me.  At the
Tennessee Gesneriad Society Show in 2007, I saw this little plant that looks just like a miniature red achimenes label
diastema sp.
Found this plant on the 'The Gesneriad Reference Web" it is actualy Achimnes erecta 'Tiny Red'.   It grew alright under my
lights, but was leggy, so I set seeds and raised them to see if it was fertile.  I put part of the seedlings outside this summer (2009)
and they really took off and made nice compact little plants (it does come true from seed).  
I emasculated the flowers before they opened to be sure that the plants couldn't self fertilize and tried several crosses, including
kohleria, smithiantha, seemania, achimenes and niphea. It takes these plants 2 months or more for the seed to ripen, but I ran out of
time in November with the last three crosses.  They are still immature, but I am going to try the seed anyway, it is 7 weeks old.  
As a side note, these plants along with my
smithiantha's and sinningia's stayed outside here in zone 6b until the temperatures finally
dropped November 24 below 30 degrees fahrenheit. I brought them inside, but I have gas heat and they started pouting immediately.
@copyright Brad Walker Dec. 6, 2009