32. Euphorbiaceae

With the increasing popularity of drought-resistant landscaping, a whole set of new plants are fast becoming the new normal -- in California at any rate. One of these, Mediterranean Spurge (Euphorbia characias, above), I had seen for a very long time throughout the state without knowing the name. Thanks to a recent issue of Sunset magazine, that mystery has been solved for me.

Euphorbia is one of 300 genera comprising the Euphorbiaceae family. Members of this family are found mainly in tropical regions and produce an impressive arsenal of toxins. It was in the Everglades that I learned about the manchineel tree (Hippomane mancinella), the sap of which is so poisonous that the slightest contact will cause one's skin to blister. In the era of the Indians and Spanish explorers, enemies were occasionally tied to manchineel trunks as a form of execution. Another famously poisonous member of the family is castor bean (Ricinus communis), the source of ricin as well as castor oil. These plants have a striking appearance, like marijuana on steroids. They certainly caught my eye when I saw saw them growing haphazardly along roadsides and in vacant lots all over California

Plants from this family produce a number of commercially valuable oils. Castor oil has a variety of uses, most of them industrial, but also curiously medicinal, despite the presence of ricin. The tung tree (Vernicia fordii) from China has also been a source of oil, used as fuel for lamps but also as an ingredient in paints and wood varnishes. At one time harvesting tung trees was an important industry in southeast Louisiana, which is where I made my acquaintance with them. They still grow wild here and there where the plantations used to be, and are unmistakable with their big leaves and nuts (below), the latter of which is the source of the oil.

In a similar way, the nuts of the Caribbean Jatropha curcas plant were long used as a source of lamp oil. More recently that oil has been identified as a clean-burning diesel biofuel. With the shift toward plant-derived biofuels becoming a reality, it is likely that the Euphorbiaceae family will continue to prosper.