On Sat, 19 Feb 2011 01:02:35 -0800, Rich Grise
wrote:

DoN. Nichols wrote:
On 2011-02-18, Michael A. Terrell wrote:
[ ... ]
Those needles would puncture large truck tires as well. Some were
just shy of 2" long, and they could go through the tread or the
sidewalls.

And one style of cactus which was around where I grew up I
called "watch-out cactus" because the needles had a dry husk on them,
and when you pulled a needle out of self, the husk stayed around nearly
forever in your skin. The husk could provide a continuing path of air
through the walls of the tire and tube.

If anyone really knows the name of that cactus (insanely
branching and re-branching bits about the diameter of a pencil or a bit
fatter), I would love to have identification. This was in South Texas,
sort of between San Antonio and Laredo, FWIW.

Caltrop cactus? ;-)

I believe those are only found in LEO county, California.

--
Happiness comes of the capacity to feel deeply, to enjoy
simply, to think freely, to risk life, to be needed.
-- Storm Jameson