En Español

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
1 rating

Monday - September 12, 2011

From: New Braunfels, TX
Region: Southwest
Topic: General Botany, Plant Identification, Shrubs
Title: How can I distinguish Hibiscus laevis from Pavonia braziliensis in New Braunfels, TX?
Answered by: Jimmy Mills

QUESTION:

How can I distinguish Hibiscus laevis (Halberdleaf Hibiscus) from Pavonia braziliensis (Brazillian Rock Rose)? Earlier this year I was given the former by a friend and former NPSOT chapter President. Then I bought a Salvia at Medina Garden Nursery, and it had a "volunteer" in the pot that they identified as "South American" Rock Rose. Now both are blooming, and they appear almost indistinguishable. Thanks,

ANSWER:

Both Hibiscus and Pavonia are genera in the plant family Malvaceae, so you would expect them to resemble one another; one source referred to them as cousins, but lets not go there. When Botanists describe plants and assign them to genera and species, a great deal of attention is paid to the structure of the flowers in addition to other morphological and chemical characteristics. There is one difference in the flowers of these genera that is easy to see, and will allow you to distinguish Hibiscus from Pavonia. Luckily, you have flowers of both plants.

Before we go into flower parts, look at this diagram to refresh your memory. We are interested in the pistil which is composed of the ovary, style(s) and stigma(s).

One character that separates the two genera is the number of stigmas at the tip of the pistil. Plants in the genus Hibiscus have the style divided into 5 stigmas, while plants in the genus Pavonia  have twice as many stigmas (10).

In the case at hand, the common name of Hibiscus laevis (Halberdleaf rosemallow), or Halberdleaf Hibiscus gives us another clue. The halberd was a type of pole axe used in the middles ages, whose shape somewhat resembles the base of the leaf of H. laevis (or vice versa).

The following links illustrate these features:

Alabamaplants.com  pictures of the stigmas and leaf shape in H. Laevis.

Greatstems.com  pictures of stigmas of Pavonia braziliensis

Greatstems.com  good illustration of stigmas in a Texas Pavonia, P. lasiopetala. Also note the leaf shape

 

More Shrubs Questions

Trees & Shrubs for a NY Slope
July 03, 2012 - Our community has a large steep slope (100'high by at least 600' wide) that is sunny & dry. The builders planted "wild flower seeds" on the slope that is now just weeds. We would like to know what...
view the full question and answer

Shrubs to block dust from dirt road
May 01, 2011 - I live on a dirt road in Northwest Missouri. Could you recommend a fast growing, low maintenance shrub/bush that will form a barrier to block the dust from the dirt road? Thank you
view the full question and answer

Shrub or small tree to hide walls in southern California
August 31, 2009 - We have multiple issues in our back yard in 92683, and will probably need an assortment of plants to accomplish it. In a nutshell, here are the basics we were hoping to fix: 1) Ugly 5 & 6 foot block...
view the full question and answer

Yellow-blossomed Shrub that Occurs in Arizona and Texas
May 08, 2012 - What is the name of the large shrubs you will see in Arizona with the bright yellow blossoms. They grow wild everywhere, and I also see them in the town. Could you please tell me the name of them, s...
view the full question and answer

Plants for steep slope in California
November 13, 2010 - Where do I find out about the specific root structure of various California native plants? Are there shrubs that have tap roots & hence are good for steep slopes? The genus of any such plants that y...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center