Euphorbia persistens (2011)

PhotoBy Rose Notheis (April 2011)

Euphorbia persistens is a member of the genus Euphorbia, which has hundreds of identified species. It is a caudiciform, which means it forms a large caudex (tuber, root) to store water, which helps it survive long dry periods. E. persistens is from tropical Africa.

All of these plants are extremely resistant to pests and diseases. They form thick stems, not leaves, which are marked by species-specific, alternating light and dark green patterns. These markings help differentiate one species from another.

I keep plants of this entire genus in a lot of morning sun and indirect sunlight the rest of the day. Some of them tolerate full sun. When watering, be sure to water thoroughly and let them dry a bit between waterings.

Euphorbia persistens and its relatives winter in my basement. They seem to like a cold, dry dormancy. Be sure they dry out well before going dormant, since they are prone to rot if the dormancy is not totally dry.

These plants will propagate from stem cuttings. To have them form a caudices, the stem must be “double cut.” So after the cuttings are well established, cut the stems again to encourage caudex formation.

Like all euphoribas, E. persistens forms insignificant, usually yellow “flowers” called cyads. All members of this genus have a white “sap.” This is toxic to insects and animals. These plants are poisonous. The sap can cause local skin irritation in sensitive people.

Treat these plants with respect and care, and they’ll grow well and prosper for you. (Yes, I am a Trekkie.) I hope this information is helpful to all of you. I also hope this is my first and last article. I prefer verbal to written communication, especially concerning these plants, which are high on my list of favorite plants.