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
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

Privacy Screening Plant for New York Narrow Site
April 20, 2013 - I need privacy screening on the side of my house in Mount Kisco, New York located 40 miles north of New York City. The area gets plenty of sun but is somewhat narrow. What evergreen bushes or trees ...
view the full question and answer

Non-native Lorapetalum chinense from Driftwood TX
March 16, 2012 - In a previous response you said that it would not be wise to plant any trees with the word Chinese in it. Does this apply to Lorapetalum (Chinese Fringe Flower)? I would like to use this plant as a ...
view the full question and answer

Esperanza failing to bloom in Odessa TX
September 01, 2009 - I have 3 Esperanza plants that have not bloomed this spring/summer. I live in Odessa, TX. We had about 5 inches of rain in July in one week (very unusual), but they have not bloomed-before or after. ...
view the full question and answer

Failure to bloom of lantanas in San Antonio
July 22, 2010 - Mr. Smarty Plants, We have lantanas in our front yard. This summer the leaves have turned white and they die to a brown color all the while the leaves are "crispy". At the beginning of the season...
view the full question and answer

Declining wax myrtles in Katy, TX
August 24, 2009 - My wax myrtle bushes were thick and green except for a few on the NE side 6 months ago when we bought the house. Now they are thin, leggy, and dropping leaves like crazy. They seem to be dying one bra...
view the full question and answer

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