Sea holly, Eryngium zabelii Big Blue, Close view of thistle-like flower head surrounded by silvery blue bracts.

Sea holly, Eryngium x zabelii Jos Eijking. Thistle-like flower heads surrounded by spiny, silvery blue bracts.

Sea holly, Eryngium x zabelii Jos Eijking. Thistle-like flower heads surrounded by spiny, silvery blue bracts.

Sea holly, Eryngium x zabelii Jos Eijking. Thistle-like flower head surrounded by spiny, silvery blue bracts.

Heliconius hecale zuleika butterfly feeding on clustered white flowers of Lantana camara

Common Water Hyacinth, Eichornia crassipes. Spikes of pale blue flowers of water plant considered invasive outside native habitat.

Water lily. Close cropped detail of Giant water lily Victoria cruziana showing textured surface beneath water and curved rim of growing leaf.

Viburnum burkwoodii. Rounded flower head of tubular, pale pink flowers on woody stem with oval, green leaves.

Poppy, Papaver somniferum. Single, open flower with white petals edged in pink above bud on bent stem.

Water lily, Nymphaea Foxfire. Large, single flower with purple petals and orange centre and mottled bronze and green leaves.

Water lily, Nymphaea Foxfire. Large, single flower with purple petals and orange centre and mottled bronze and green leaves.

Virginia Bluebell, Mertensia virginica with branched stems of clustered, funnel-shaped blue and violet coloured flowers.