Rent Shop Volunteer Join

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 Plant Identification Questions

Identification of plant growing with purchased plant
September 23, 2013 - I purchased a heurchera and there was another plant that was growing in the pot with it. I planted both together in my garden. The "other" plant is growing and none of the gardeners around here has ...
view the full question and answer

Plant Identification from Cold Lake AB
August 03, 2012 - How can I send a picture for you to help me identify a plant that grows in my garden that no one can seem to identify? I have taken a picture of it but can't seem to be able to attach it to this que...
view the full question and answer

Lily of the Valley growing in Red River County, TX
March 26, 2012 - Mr. SP, I just returned from Red River County, TX where I observed Lily of the Valley growing in a very old cemetery. Is this unusual for this area of the country?
view the full question and answer

Identification of vine from Las Vegas NV
July 11, 2012 - I'm interested in identifying the vine shown by the leaf in this photo: https://picasaweb.google.com/lh/photo/zR3R4JSPYcCI4ESczNXWM4h8z33Cq5cyZNqSSYf9hx0?feat=directlink My mother-in-law got one o...
view the full question and answer

Yellow lupine-like flowers
May 10, 2009 - I recently visited Hodges Gardens near Many, LA. There was a large plant, 2' tall with spikey yellow lupine-like flowers. Plant had hairy leaves and a big spread--I'm sure it is a wild perennial. ...
view the full question and answer

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