Sarcochilus ?

[Andrew]

I doubt it's Southern Cross. I agree there's hartmannii in it. The yellow lip and fairly broad pattern at the centre of the flower indicate (a lot of) fitzgeraldlii in the background. I'm not convinced about it having any australis in it. It's a bit hard to judge the shape from the angle of the photo but I can't see anthing in the shape of the flower that can't be explained by fitzgeraldii. As for an ID, it could be fitzhart, Cherie or a lot of other white breeding.