Holly, Ilex aquifolium, Close front view of a sprig of spikey leaves and a cluster of red berries.

Lion's tail, Leonotis leonurus, Side view of tubular orange flowers in a spikey whorl encircling a square stem.

Lion's tail, Leonotis leonurus, Side view of tubular orange flowers in a spikey whorl encircling a square stem.

Mexican pinenut, Pinus cembroides, Masses of pine nuts in a pile with moody light.

Feathertop, Pennisetum villosum, Close up showing spiky detail.

Feathertop, Pennisetum villosum, Close up showing spiky detail.

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

Agave, Agave attenuata, Close up showing texture.

Agave, Agave attenuata, Close up showing texture.

Sea holly, Eryngium planum, backlit growing against bright green foliage.

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.