Sea holly, Eryngium planum, Growing against bright green foliage.

Dragon tree, Dracaena fragrans, Viewed from underneath showing the long trunk and spikey foliage, Madeira.

Bougainvillea, Sprig of flowers backlit against clear blue sky.

Agave, Agave attenuata, Close up showing texture.

Russian sage, Perovskia 'Blue spire', Side view of several white stems with feathery silver leaves and sparse, furry, blue purple flowers, creating a transparent effect.

Globe thistle, Echinops 'Veitch's blue', Five white stems with spikey, spherical, deep blue heads viewed from an angle, creating a dynamic effect.

Borage, Borago officinalis, Close view of some sprays of blue flowers, some of which have dropped leaving the empty sepals and bee collecting nectar from a flower.

Borage, Borago officinalis, Close view of some sprays of blue flowers, some of which have dropped leaving the empty sepals and bee collecting nectar from a flower.

Borage, Borago officinalis, Close view of some sprays of blue flowers, some of which have dropped leaving the empty sepals and bee collecting nectar from a flower.

Borage, Borago officinalis, Close view of some sprays of blue flower with black stamens forming points, some flowers have dropped leaving the empty sepals.

Borage, Borago officinalis, Close view of some sprays of blue flowers, some of which have dropped leaving the empty sepals and bee collecting nectar from a flower.

Eucalyptus, Eucalyptus globulus, Cut out of three mature leaves on a piece of stalk.