need help Finding plant name for grandson

[BillyBo278]

Hi out there,
I need help finding a plant name for my grandson.  Somebody in a campground in
FL gave me a thorn from something, it looks like a horn for a cow.  It's about
3" spread and about the same color and is attached to a small twig.   I sent it
to my 11 year old grandson in NY and later he took it to school and his teacher
told him that if he could find out what plant it came from he would get extra
points in class for the info.  We would appreciate any info you could give us.
Grandfather's "E" Mail: billybo278      Grandson's "E" Mail: tms3b at juno.com
Thanks for the help in this matter.
Bill