En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Friday - April 04, 2014

From: Leander, TX
Region: Southwest
Topic: General Botany, Drought Tolerant
Title: Water-saving strategies of drought-tolerant plants
Answered by: Joe Marcus

QUESTION:

Although "drought tolerant" plants are fairly well documented, it's clear that many different strategies are responsible, such as a huge root system (like Mesquite). I'm interested in learning the characteristics that allow plants other than succulents to USE LESS water to thrive. I believe that small or waxy leaves are such characteristics. Are there other qualities that might help us decide which natives to plant, so as to reduce our water consumption?

ANSWER:

It is true that plants native to arid lands employ a variety of methods to reduce the amount of water used, including deeply-growing roots, fleshy water-storage organs (roots, bulbs, stems, leaves, etc.), reduced leaves and waxy epidermal coatings.  Another strategy for water conservation used by many plant species native to areas of low rainfall is CAM photosynthesis.  

Arid country plants do not conserve water so much by sequestering less water in their tissues -- to the contrary many of them actually store more water than species native to areas of higher rainfall.  Rather, these species reduce the amount of groundwater removed from the soil and passed to the atmosphere through the process of evapotranspiration.  CAM plants accomplish this by enabling their stomata to remain closed during the day when evapotranspiration rates are higher and carry out their photosythetic process at night when evapotranspiration rates are lower.

So the CAM process itself is not so important to water-use reduction as what the process allows those species employing it to do.  That is, it allows them to carry out photosynthesis at night when evapotranspiration is reduced.  With less than 10% of the earth's plant species employing the CAM carbon fixation process, those plants that do, use less water than those using the more typical C3 and C4 carbon fixation pathways.

Whatever water-saving strategies are employed, the important fact is that plants native to arid lands are well-adapted to their environment and the reduced availability of water there.  For that reason, the method of water savings is somewhat moot.  Native plants' adaptation to low water availability is in large part why we strongly encourage their use in landscapes within their native ranges.

 

More General Botany Questions

Carolina wolfberry blooms but doesn't produce fruit
May 10, 2012 - I have had my carolina wolfberry for 2 years now ( I got it at the Wildflower center), it seems to be doing well, creeping all over the flower bed with some branches on the ground up to 6 ft long. It ...
view the full question and answer

Drawings of Illinois native wildflowers
July 15, 2006 - I am looking for line drawings of Illinois Native Wildflowers to use for educational material for visitors to our new City Park. We plan to have signs throughout the park describing how Native Americ...
view the full question and answer

Trillium phototropism
May 16, 2010 - I'm SURE you haven't had this question before. I live in northern Michigan in a wooded subdivision where we have clouds of wild grandiflorum trilliums growing in the woods on either side of the roa...
view the full question and answer

Is Esperanza a deciduous or an evergreen plant?
March 08, 2009 - I've read that Esperanza/Tecoma Stans is an evergreen. I planted one last year that seemed very healthy, but it dropped its leaves in late fall and looks (at least) dormant now. Will it come back o...
view the full question and answer

Smarty Plants on aceae
March 21, 2005 - How is the family suffix "-aceae", as in Asteraceae, pronounced? I find disagreeing claims in my searches- "ay-see-ee" and "ay-see-ay" seem to be the most common, but I've also seen just "ay-...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center