Euphorbia milii

Crown of thorns
Euphorbiaceae

EUPHORBIA

Flower is technically a cyathium, consisting of fused bracts that form a cup around the much-reduced true flowers. Cyathia may appear singly or in clusters. In some cases, as with poinsettia (E. pulcherrima), additional bracts below provide most of the color. Fruit is usually a dry capsule that releases seeds explosively, shooting them up to several feet away. Many euphorbias are succulents; these often mimic cacti in appearance and are as diverse in form and size.

All euphorbias have milky white sap that is irritating on contact or toxic if ingested (degree of irritation or toxicity varies, depending on species). Before using cut flowers in arrangements, dip stems in boiling water or hold in a flame for a few seconds to prevent sap bleed. All need well-drained soil.

Euphorbia milii

The climbing stems of this woody shrub grow 1 to 4 ft. tall, 1 1/2 ft. wide; bear pairs of red flower bracts nearly all year. Branches are covered with long, sharp thorns; evergreen leaves are roundish, thin, light green, 1 1/2 to 2 in. long, and usually found only near branch ends. Can be sheared as a low hedge, grown as a pot plant for indoor use, or trained against a fence or espalier.

Many varieties and hybrids varying in form, size, and bract color (yellow, orange, pink). Plants in the Supergrandiflora series are hybrids (often sold as varieties of E. x lomi) with large flowers in shades of yellow, pink, orange, and red; some are attractively speckled.