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

Sunday - August 18, 2013

From: Elmendorf, TX
Region: Southwest
Topic: General Botany, Plant Identification
Title: How does Styrax youngiae differ from other Texas Styrax species?
Answered by: Nan Hampton

QUESTION:

How does the Styrax youngae differ from other Texas styrax? Where can I find a description of all the Texas styrax trees?

ANSWER:

First of all, Styrax youngiae is no longer a separate species.  It is now designated as a subspecies, Styrax platanifolius ssp. youngiae (Young's snowbell), of Styrax platanifolius (Sycamoreleaf snowbell).  Here is the Texas county distribution map from the USDA Plants Database.  There three other subspecies as well:

Styrax platanifolius ssp. texanus (Texas snow-bell)  Here is the Texas county distribution map from the USDA Plants Database.

Styrax platanifolius ssp. platanifolius (Sycamoreleaf snowbell)  Here is the Texas county distribution map from the USDA Plants Database.

Styrax platanifolius ssp. stellatus (Hairy sycamore-leaf snow-bell)   Here is the Texas county distribution map from the USDA Plants Database.

There are also two other species that occur in Texas:

Styrax americanus (American snowbell)  Here is the Texas county distribution map for the USDA Plants Database.

Styrax grandifolius (Bigleaf snowbell)  Here is the Texas county distribution map for the USDA Plants Database.

You can see a description of the Genus Styrax in the eFloras.org (Flora of North America) database.  You can see that S. platanifolius does not have axillary flowers; whereas, S. americanus and S. grandifolius both have at least some axillary flowers.  The difference between S. americanus and S. grandifolius involves differences in the length of the calyces and corolla tubes as well as the type of fruit.

Next, to see the differences between the different subspecies, go to the eFloras.org page for S. platanifolius and you will see that S. platanifolius ssp. platanifolius and S. platanifolius ssp. stellatus has the abaxial surface (the underside) of the leaves mostly glabrous (without hairs) or at least visible through the hairs; whereas,  S. platanifolius ssp. texanus and S. platanifolius ssp. youngiae have their abaxial surface covered in pubescence (dense hairs).

S. platanifolius ssp. texanus has glabrous (without hairs) leaf blades adaxially (on the upper leaf surface) and S. platanifolius ssp. youngiae has stellate pubescence (star-shaped hairs) on the adaxial leaf surface.  There are also differences in pubescence on stems and other structures.

 

From the Image Gallery


Sycamoreleaf snowbell
Styrax platanifolius ssp. platanifolius

Hairy sycamore-leaf snow-bell
Styrax platanifolius ssp. stellatus

Texas snow-bell
Styrax platanifolius ssp. texanus

Sycamoreleaf snowbell
Styrax platanifolius

American snowbell
Styrax americanus

Bigleaf snowbell
Styrax grandifolius

More General Botany Questions

Every plant in Texas
December 01, 2008 - Do you know every plant in Texas? Alexis
view the full question and answer

Comments on article in Austin paper
January 22, 2012 - Why can't we comment on your piece in the Statesman? It says no comments possible at the bottom.
view the full question and answer

Define monoculture from St. Croix Falls, WI
May 30, 2014 - What do you call a dense stand or carpet of one species of wildflower? Our botany professor told us but that was 40 years ago!
view the full question and answer

Why will my Butternut trees not produce nuts in Tennessee?
May 06, 2009 - I have 2 butternut trees planted about 20 ft from each other. I see the long blossoms on each tree but I have not gotten any nuts from either tree. I do not know if I have a male and female or if th...
view the full question and answer

Which plants grow well together
April 17, 2009 - Please tell me what plants grow best together and which plants do not grow very good together
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center