Hmm, my notes from the ATP tool don't show me sending you any tatsoi ... was I a Bad Boy and sent un-asked-for seeds?
I guess they weren't from me.
Looking at my own "HAVE" list, the closest thing to a cultivar name for tatsoi is from Tainong Seeds: they sell "Takuchoy" which I thought was mandarin for "Tatsoi".
. ... Now that I do more research , Takuchoy ?= Ta Gu Choy = Tagu Choy looks like it has much longer stems than Tatsoi. And fat veins. So I don't know, now! I'll have to grow that out and let it get older, see if the rosettes get taller.
http://www.clovegarden.com/ing...
My Tatsoi form other sources has just been called "Tatsoi", except for one "Red Tatsoi" and one "Green Tatsoi".