I got this from Afri Orchids of South Africa in Spring 2018. It is the first bloom for me (Nov 23, 2018). It is a small genus and here is the artificial key (link). According to this page, the lateral sepal should have a basal pouch-like outgrowth. I'm not completely sure what this means (I need to dissect the flower next time), but I think that B. maudiae seems to be the match (I'm not 100% sure, though). Gilles has one posted here, and they look somewhat similar. I appreciate any information about the ID. It is a tiny plant, the thick leaf is about 2.5cm (1") long. The flowers are tiny, too, so I had to crop quite a bit. I'm growing it at the cool-end of intermediate; max/min daily temperature of 29/18C (84/65F) in the summer and 21/13C (70/55F) in the winter.