Conical flower head of Eryngium giganteum surrounded by spiny, silvery bracts.? Paul Tomlins / Flowerphotos

Orchid, Orchidaceae, Close up of blue dyed flowers.

Orchid, Orchidaceae, Close up of blue dyed flowers.

Orchid, Orchidaceae, Close up of blue dyed flowers.

Orchid, Moth orchid, Phalaenopsis, Studio shot offlower against blue background.

Orchid, Blue vanda with pale blue petals marked with checkerboard pattern at the 2011 Orchid Festival in Chiang Mai, Thailand.

Orchid, Blue vanda with pale blue petals marked with checkerboard pattern at the 2011 Orchid Festival in Chiang Mai, Thailand.

Orchid, Blue vanda with pale blue petals marked with checkerboard pattern at the 2011 Orchid Festival in Chiang Mai, Thailand.

Orchid, Cattleya.

Orchid, Moth orchid, Phalaenopsis.

Vanilla, Vanilla planifolia.

Orchid, Epidendrum radicans.

Orchid.