After reading this explanation of what allows the seeds of the Bletilla Striata to be so easy development without using in vitro culture i'm curious to known which other type of orchides is similar.
Interesting question. From experience I know Spathoglottis and Phaius also have relatively large seeds, like Bletilla. I wouldn't be surprised if these and other close relatives also have some endosperm - but I have no hard evidence to support this, just a guess.