Open a picture in Preview (find it in the Finder and open it that way). Hit Command-I and choose the details tab.
In the top section there should be an Orientation property. For me a "standard" landscape is 1 and portrait 8. Note that this does not surprise be. There are 4 orientations allowing for upside down in landscape and both rotations for portrait which are almost certainly 1, 2, 4 and 8 which correspond nicely to bit patterns in binary.
If yours is 0 then either the camera doesn't capture it in the mode you are shooting, it's getting stripped in import or Apple's library does not understand the orientation data in the image file...