Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Friday - August 28, 2009

From: Tucson, AZ
Region: Southwest
Topic: Drought Tolerant, Herbs/Forbs
Title: Range and adaptability of evening primrose from Tucson AZ
Answered by: Barbara Medford

QUESTION:

What is the natural range of the evening primrose? What adaptations does it have to live in the arid Southwest?

ANSWER:

There are 12 plants with the common name "evening primrose" in our Native Plant Database. There are 4 native to Arizona, so we chose to give you the ranges of those. 

Calylophus hartwegii ssp. pubescens (Hartweg's sundrops) -blooms yellow March to August. Range in Arizona from USDA Plant Profile. Range in North America

Calylophus serrulatus (yellow sundrops) - blooms yellow April to July.  Range in Arizona from USDA Plant Profile. Range in North America

Oenothera caespitosa (tufted evening-primrose) - blooms white April to August. Range in Arizona from USDA Plant Profile. Range in North America.

Oenothera speciosa (pinkladies) - blooms white or pink February to July. Range in Arizona from USDA Plant Profile.  Range in North America. 

To try to find out what were the traits of these plants that made them drought resistant, we found three websites that had a great deal of information:  Central Washington Native Plants  Plant Adaptations in Arid Environments; Plant Life in the World's Meditteranean Climates, by Peter R. Dallman, from University of California Press; Arizona Sonora Desert Museum Center for Sonoran Desert Studies How Plants Cope with the Desert Climate.

From this information, we found that the characteristics that the plants share that contribute to their survival are:

Long, narrow leaves, to avoid loss of moisture. Leaves also are hairy or downy, are blue-gray on the underside, and may fold up in the heat of the day.

Most of these plants bloom in the evening, and blooms close the next day when the heat begins to rise, again reducing moisture loss. 

Taproots-the seedlings quickly put down a taproot for moisture, and the mature plant develops a network of fine roots near the surface of the soil.

Plants may go dormant in summer, resprouting with rains.

From our Native Plant Image Gallery


Calylophus hartwegii ssp. pubescens

Calylophus serrulatus

Oenothera caespitosa

Oenothera speciosa

 

 

 

 

 

 

More Herbs/Forbs Questions

What are the Native Dianthus?
October 03, 2015 - What species of Dianthus is native to North America?
view the full question and answer

Turk's Cap not returning from Plano TX
April 02, 2014 - My Turk's Cap has shown no signs of coming back this year as of March 31. I pruned to about 12 inches because it was so bushy last year and it was not mulched thru our harsh winter (10 degree low and...
view the full question and answer

mixed species privacy hedge in Central Texas
March 24, 2016 - I need to plant a privacy hedge along a fence line. I am in east Austin, blackland prairie soil. The soil is rich, usually at least moist but not soggy, and I find lots of worms when I dig. The fen...
view the full question and answer

What to plant between patio flagstones in Austin, TX?
May 16, 2011 - I would like to plant something between my flagstones on the patio. Something that doesn't require a lot of water, low growing, and can stand a little to moderate traffic. It is in a shade to partly...
view the full question and answer

Indian Paintbrush outnumbering our Bluebonnets this year.
May 26, 2015 - We noticed we have more Indian paintbrush than bluebonnets in our front yard this year. Our issue is we also have more spear grass than normal. Is there a way to control this grass without killing th...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.