Thursday, August 27, 2009

Fasciation [not a typo)]

I’m fascinated with fasciation. The origin of the word means bundling or flattening. No matter what the translation of the word means, I’m always on the lookout for fasciated plants.

I have a collection of dried fasciated plants. But the largest one I’ve ever seen is pictured on the left. [Except, perhaps, some cactus plants in Arizona which surely carry the record of the heaviest fasciations.] Alas, I could only photograph it and not add it to my collection. Usually the fasciation is a broad widening of the top of a limb. What makes the photo of on the left so amazing is the upside-down skirt. So, not is it the largest fasciated plant, it is the only one I know of with a shape other than splayed out in flat plain. The usual growth of this Echium pininana is found in the background. In the photo on the right is one I have grown. This plant grew to the height of 24 feet. For more examples search “fasciated” in Google images,

The cause of this phenomena is not understood. Reasons for this freak event include: damage to the apical bud [tip]; viruses; herbicides [which surely doesn’t happen in the wild where I have found the most examples]; bacterial infection; cytokinin that appears to have the ability to stimulate the proliferation of a wide spectrum of cell that is found in the xylem. Cytokinin is thought to proliferate cells in the plant; spontaneous mutations; bacterial infection, mite or insect attack; or chemical or mechanical damage. Some plants may inherit the trait.

Among the examples in my collection are: Echium fastuosum [Pride of Madera], an oak stem [it’s rare to find fasciation in hardwoods like oaks], cockscomb celosia [Celosia argentea var. cristata is one of the few plants that passes the mutation on as a true “fixed” fasciation], and evening primrose [Oenothera spp.].

Let me know if you've found a fasciated plant.

Please post a comment - I want to know what you think.

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