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Observations of a Naturalist Online Articles about nature - by Boyd Shaffer, artist /naturalist
This Article: Euphorbia - It can be a "sticky" subject.
When an American travels abroad they always see plants and animals that remind them of home. Many times they are not related to the American species at all , and they are often members of entirely different families. When in Africa one sees a plethora of spiny plants that resemble cactus that are euphorbias. candelabra tree in bloom          In fact the candelabra tree is a Euphorbia that grows up to forty feet tall with many upright cactus-like limbs and many spines. But they have very tiny deciduous leaves. Other species are vine-like and still some are Milkweeds with round leaves eight inches in diameter. Perhaps the best known member of this family is the Poinsettia. Along the equator where it receives about twelve hours of daylight and twelve hours of darkness year around, the upper leaves and leaf bracts remain red throughout the year. Poinsettias grow to be large ornamental trees there.           One must be careful not to mistake one of the many cacti that have been transplanted into foreign lands. Cacti, like Hummingbirds, are endemic to the Americas. Native to nowhere else on earth.           The most common cactus imported into foreign lands are the opuntias, or "Prickly Pear" group. The spines may be burned off and the leaves then used for cattle or human food. One cultivar is very large and has been bred without spines, this is the most desirable cactus for food. Of course, all cactus fruits are edible and some are very good. Many other cactus species have been introduced for ornamental uses.           In America we are all familiar with Milkweed which is our most abundant Euphorbia. In fact it is the only food plant utilized by the Monarch Butterfly (Danaus plexippus), and if the Milkweed is not present, the Monarch cannot live. An interesting thing is, that butterfly was an American endemic until it began extending its range and crossed the Pacific Ocean. It stopped and colonized every place where milkweeds grows. Additionally it went into Asia and throughout Europe. Oddly enough it did not enter Africa which is the home of hundreds of Euphorbias including Milkweeds. Euphorbia bussei           A closely related species which is known as The Queen, is found there but it does not have the black markings of the Monarch, and in captivity does not breed with that species. It, however, is improporly listed in some books as a Monarch.           A beautiful Queen lives in Southern California, it is non-migratory, does not breed with the Monarch and also lacks the black wing markings. It, as with all Queens, is not bright reddish orange but more of a orange-tan color. It is not as restricted to feeding upon only one species of Euphorbia as the true Monarch does.             So what sets the Euphorbias apart from other plants? Not the latex, nor the poison principle present, but the way they reproduce. All plants are identified that way, and Euphorbias are very different in the way they reproduce.           Because Alaska does not have Euphorbias, the Monarch cannot survive there.           All members of this family have white latex and are toxic and many others are deadly poisonous. During the early part of World War two, people were collecting latex from wild Milkweed for the government. They were also growing it as a cash crop. It makes a fairly good rubber substitute, but science found a way to make better latex chemically so the Milkweed latex was no longer needed.          -End Euphorbia uhligana OBSERVATIONS INDEX

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