Bucephalandra is still a fairly new plant species, many names out there are fantasy names given for example from the region where it is found or the way it looks Blue wavy green with purple dots etc.. there is a enormous range of Buce spp. in the trade that are collected in nature by amateurs for the trade and not scientificaly determined or categorized. That makes it very difficult to come up with any conclusive answer.. 🙂
Anubias is a very popular plant sp. in the hobby already cultivated for a very long time. The longer it is in cultivation the more var. appear. Most popular Anubias var. are actualy for its majority a spinoff from the Barteri. Names like Bonsai, Nana, Nana petite, golden and few others are all Barteri spinoff. In the nursery they seperated small staying strains with specific grow characteristics like the barteri nana petite to finaly grow a rather stable small staying var. But in the end it geneticaly stays a barteri with the genetic abbility to grow to it's full size again. This obviously works also the other way around as well, that a large barteri shows new dwarfed growth. It could be that surtain conditions trigger the plant to do this. If so nurseries growing it or the nursery that discovered it doesn't reveale this. DOn't know but never found any reference of conditions to make a anubias stay smaller. But i guess it was just a mater of chance discovey by a nursery that some parts of the plant stayed rather small, they devided the small var. from its mother and vegetatively reproduced a smal strain that originated from a big one.
For some new crypt spp. it is the same story, for example the Lutea Hobbit.. IS a dwarfed spinoff from i believe the C. Walkeri, that has rather potential to grow big. The lutea hobbit is rather new in the trade and i bought a few pots.. A few of those plants didn't grow at all but also a few forgot they were dwarfs and grow full Walkeri size. The longer it is in cultivation the higher the chance that the dwarfed strain becomes stable.. There is no 100% garanty..