Aestivation.

The arrangement of the parts of a flower within the bud, usually referring to sepals and petals.

Valvate.

With the margins adjacent without overlapping.

Imbricate.

Petals (or sepals) overlapping, as in a tiled roof.

Contorted.

Petals (or sepals) twisted in the bud so that they overlap on one side only; spirally twisted