Plant Growth Gone Awry

Published on: Jun. 21, 2011

fasciated black-eyed susan flowerOnce a year or so I receive photos of a strange-looking flower that someone has photographed, usually from a field of typical flowers of the same species. The normally slender, round stem is broad and flattened and often wavy, so that it looks almost ribbon-like. The flower head is much elongated and curved and has lost its normal radial symmetry. Botanists call the condition fasciation, from the Latin fascia, meaning band, a probable reference to the abnormally wide and flattened stem. Fasciation, also known as cresting, occurs uncommonly but has been documented over time in more than 100 different species of plants.

Plants grow from the production of new cells in a growing point called a meristem. Fasciation results from the abnormal growth of tissue from the meristem and may be related to an imbalance of hormones in the plant. The cause can be genetic, or it can result from environmental damage from bacteria, fungi, viruses, mites, insects or physical or chemical damage. The abnormal growth can occur in any part of the plant, including the roots. An odd-looking wildflower may look normal the next year if it dies back to the ground during the winter, unless the problem has a genetic cause. Long-lived plants like some of the fasciated cacti will be oddly formed for life. The ornamental plant celosia is cultivated in a fasciated form and called “cockscomb,” because of its arched and undulating flower heads.

fasciated brown-eyed susan

While landowners may be shocked and concerned to see a fasciated plant on their property, the condition is usually just a random oddity that is not contagious and probably won’t even persist among a population of annual or short-lived perennial plants.

Seeing the range of possibilities of growth in a fasciated plant can make us appreciate the regularity in which the  normal growth pattern of a plant species is routinely followed. Despite the freakish appearance of the black-eyed Susan in the photos, the overwhelming majority of individuals of that species are nearly identical in their growth form. For additional photos of odd-looking fasciated plants, do an Internet search for images with “fasciation” as the key word.

 

Photos by Megan Ordway

 

 

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Comments

On June 23rd, 2011 at 9:40am smitht2 said:

Conrad: There are multiple meristems in a single plant. Each growing stem tip, each flower and leaf bud and each tip of a root will have meristematic tissue. If the cause is genetic, then multiple meristems could be affected on the same plant. In other cases, the fasciation is only observed on one part of the plant. The root may show fasciation and not the stem or flowers.

On June 23rd, 2011 at 7:35am Melissa Daniels said:

My cone flowers in my home garden have this fasciation. there is always 1 flower each year this happens to. this year I watched a bud that started before the plants were 6 inches high, too early for blossoms none of the other plants were close to buding. the stem appeared to be normal. the bud was large & looked symmetrical. As it bloomed the flower elongated. it looked to me like a Siamese twin the center face of the flower is about 3 inches long & is so curved there is about an inch separation form the edges. I'm glad to know the name of the condition. thank you,

On June 22nd, 2011 at 9:13pm Conrad said:

How would the root, stem and flower all be susceptible to fasciation, do they all have the same meristemmatic source??
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