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
Not Yet Rated

Thursday - September 01, 2011

From: Fresno, CA
Region: California
Topic: Plant Identification
Title: Origin of thorned plant-like object falling from the sky
Answered by: Nan Hampton

QUESTION:

This morning while walking I felt a prick on my arm, like something had bitten me. I looked and saw what appeared to be a very tiny little plant with a thorn on it sticking out of my arm. I pulled it out and in a few moments felt another one. Now it is evening and the site still itches. Any idea what it might have been? I was not in any heavy brush but there were some tall trees overhead.

ANSWER:

The most likely possibility I can think of is that you were struck by small leaflets with spiny stipules. Stipules are the small paired appendages at the base of the petiole (stem) of a leaf.  Several species of Central American acacias have impressively large spiny stipules.  Robinia pseudoacacia (Black locust) is a species native to North America with a bit more modest stipular spines.  It has been reported in California in counties adjacent to Fresno County.  Click "California" on the USDA Plants Database distribution map to see counties where it has been reported in California.  You can also see the spiny stipule on the photograph on that page.  Here is a drawing showing the leaves and the spines and here is a photo.  The tree can grow from 40 to 100 feet tall and is considered invasive in many areas, including California.  One acacia relative, Prosopis pubescens (Screwbean mesquite), with spiny stipules grows in Fresno County and can reach a maximum of about 30 feet.  Here are photos showing the spines.  An insect or small mammal feeding on the tree, could possibly chew on the newly formed leaflets at their base and cause them to fall from the tree with the stipular spines attached.  One species of ant in Africa prunes new leaf shoots (presumably along with the spiny stipules) from acacia trees there.  (Young, T. P., M. L. Stanton & C. E. Christian.  2003.  Effects of Natural and Simulated Herbivory on Spine Lengths of Acacia drepanolobium in Kenya.  Oikos Vol. 101, no. 1: 171-179). 

Whatever the prickly plant-like objects are, it seems likely they fell from the tall trees you said you were walking under.  Your best bet, then, is to go back and try to determine what the trees are.  If you have photos of the trees and/or the prickly object, you should visit our Plant Identification page to find links to plant identification forums that accept photos for identification.

 

More Plant Identification Questions

Visual difference between Strophostyles umbellata and S. helvola
September 06, 2012 - I know that Strophostyles umbellata is perennial and S. helvola is an annual, but can you tell me how to visibly distinquish between S. umbellata and S. helvola.
view the full question and answer

Identification of Canopy Plant
December 01, 2008 - I recently adopted a large house plant from a neighbor who moved away. He called it a 'Canopy Plant', but I'm having no luck with that name when I search for care tips. It seems to be in poor healt...
view the full question and answer

What trees in Austin right now have yellow leaves that are falling?
December 08, 2008 - Right now there are trees in Austin that have bright yellow leaves. Do you know what trees native to Austin turn a very bright yellow in November? It looks like now the leaves are starting to fall off...
view the full question and answer

Identity of a plant at UGA Trial Gardens 15 years ago
August 14, 2012 - Looking to identify a plant that was in UGA trial gardens about 15 years ago, large plant with purple flowers, fuzzy leaves like a lambs ear. Thought it started with a Thiobana or something like that
view the full question and answer

Identity of the mass fields of yellow flowers in North Texas
March 23, 2012 - Are the mass fields of yellow flowers we are seeing in north Texas now likely to be Indian Mustard (brassica juncea) or Charlock (brassica kaber or sinapis arvensis)? We are teaching a wildflower ide...
view the full question and answer

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