Crest Fallen?

Euphorbia neriifolia, crested

Hardly! Succulent plant collectors are jubilant when plants “crest” to form handsome aberrant growth forms. And botanists are amused also, because “monstrous” forms give new clues as to how plants grow and develop.

Walking through the Huntington Desert Garden Conservatory, visitors can examine numerous crested growth forms, specimens that are numerous not because they are common, rather because they are rare. It turns out that people who love plants place extra value on uncommon shapes, colors, and textures, so any collection or garden will showcase extra doses of atypical forms. Crests, particularly, are rare in nature because plants do not frequently abandon their standard, highly functional architecture.

Stems are rod-like or columnar because they grow from points. Within each growth point (the apical meristem) there is inherent order – order that yields vegetative stems and leaves, as well as the basis for a different organization that produces fertile structures (flowers in highly reduced inflorescences, in the case of Euphorbias). That order prevails 9,999 times out of 10,000, or even more dedicatedly. But once in a rare while, one time in a million or more, that order takes on a new dimension.

Euphorbia lactea, showing convoluted fans of tip-growth

In the Euphorbias pictured, the growth “point” has become a line of cell propagation, producing new stem (and leaves) along a leading edge. That line of new growth generates undulating fans of stem. This could happen in almost any plant, but in succulents, with their thick and juicy stems, the crested growth can be particularly amusing, even desirable. Most importantly, the crested growths can be collected, rooted (or grafted), and cultivated to yield handsome specimen plants. The resulting rare, curious, and potentially uniquely-attractive examples are celebrated and shared.

Euphorbia malevola
Euphorbia saxorum

Through a most contorted path, these stretched and twisted Euphorbias are connected to Richard Burton and Elizabeth Taylor, well, rather to Anthony and Cleopatra. We learn that in naming the genus Euphorbia (which I always thought meant “true forb, i.e/ herb), Linnaeus was accepting an ancient name for the plant group (which numbered 56 species in his Species Plantarum), a name said to have originated with Juba, son-in-law to Antony and Cleopatra, and ruler in his own right. The name Euphorbia was given to a plant honoring Juba’s physician, Euphorbus, who (it is claimed) introduced a particular form of the nearly spherical Euphorbia obesa to the materia medica as a potent laxative. The fame of this group shows also in “spurge” – its common name, which comes from the purgative value of common forms. It is a moving and romantic tale of plant names.

Dr. Brian Dorsey

Today, Euphorbia is a big deal, diverse and curious, known for its eye-stinging latex (should you carelessly rub an eye while working with the vegetation). The Huntington is fortunate to have our own expert in this group as Chief Scientist, Brian Dorsey. Today, Brian works to unravel the complex evolutionary history of Dioon, a group of cycads. But in past work, Brian contributed significantly to the understanding of relationships among the many sap-ridden plants that make up the Euphorbiaceae.

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