When half a flower is the wrong color…

If you’ve spent enough time around flowers, you’ve probably seen this. It isn’t exactly common, but it happens, and is so distinctive that you’ll almost always notice when it happens, as I did on one of my gladiolus the other day.

sectoralchimera

Everything else is as normal, but a chunk of the flower is white instead of the usual soft peachy white.

What we have here is a sectorial chimera. Chimera means an organism with two (or more, I suppose) genetically different cell types, and a sectorial chimera is when there is one distinct section of the plant made up of a different cell type.

And why is this showing up in my usually pink gladiolus? Well, somewhere early in the development of this flower spike, there was a chance mutation in a cell. That mutation stopped those cells from producing the usual pink pigment, so the mutant cells make white flowers. The new mutation and the original cells continued to grow and divide, so some of the flower is from the newly mutated white form, and some is the original cell type.

Now, when people hear the word “mutant” they either think x-men or nuclear fallout, but the fact is mutations are a perfectly common, normal part of everyday life for organisms, and of course are critically important to continuing evolution.

This type of bicolored flower is cool looking, but certainly a one-off. Sectorial chimeras are very unstable. Next year, most likely, the flowers will just be pink again, or possible a branch will send off pure white flowers. So when you see a sectorial chimera in the garden, take a picture, put it on facebook, and enjoy it because it probably isn’t coming back.

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Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and an Associate Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - www.facebook.com/TheGardenProfessors "The Garden Professors" Facebook group - www.facebook.com/groups/GardenProfessors Books: http://www.sustainablelandscapesandgardens.com

2 thoughts on “When half a flower is the wrong color…”

  1. This article makes me think of the banks of bonesets (Eupatorium spp.) along the roadsides here in Georgia that are oftentimes populated with variegated plants. I was wondering if they are an indicator of pesticide application, as I’ve seen plants become variegated (instead of dying) when sprayed with a poison.

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