Friday physiology fun

It’s still cold and wintery, so let’s imagine ourselves in a happy place…warm, sunny, dry…with dead lawns.

As the photo shows, the turfgrass is dead; this happens every summer during the Pacific Northwest’s droughty summers.  Yet many of the weedy species are obviously thriving.  Why?

Remember, this is a physiology quiz.  You can discount herbicides, fertilizers, etc.  This is a cool (no pun intended) adaptation that many species native to dry, subtropical to temperate environments possess.  And there are serious implications for water use related directly to this adaptation, or lack thereof.

Let’s see lots of brainstorming on this – no points deducted for trying!  (And if you are a true ecophysiology geek, let other people try first before posting the answer.)

Published by

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

5 thoughts on “Friday physiology fun”

  1. Well since your picture won’t expand and the true identity of the weed involved can’t be seen a number of quesses will have to suffice.

    Mostly I would have to say this is a function of the root system. It could have a tuberous water storing root reaching in to the lower stems or deep penetrating roots to reach water lower down.

    Leaf adaptations that dramtically slow water loss is another option. Waxy coatings or hairy leaves can slow water loss. Hairy leaves can collect dew. Silver coloration can reflect the sun to slow water loss, but that does not look to be the case here.

  2. Yep…..that is why I now leave the flat weeds to grow in my lawn. Those flat little legumes really green up the place with their nitrogen fixing.

Leave a Reply