Notocactus magnificus flower buds opening

These are the hairy, brown buds I photographed on 6 Dec (see here), and now they are opening. I intended to photograph the yellow buds this morning before they started to open (the shape was more appealing), but I was busy with other things and the opportunity was lost. By the time I got to them, it was possible to peer inside at style and stamens. I love the brown scales surrounding the bud that earlier enveloped them completely.