[SVBC] Puncture vine/Goathead warning update on Stonebrook

[PaulW at enet.com]

For those who don't know what the puncture vine/goathead plants look like,
or who think yellowstar thistle causes flats, please page down to the URLS
and descriptions in my original email below:

(I'm not sure why Ellen thought it was useful to forward only a later
followup reply to my WWBC email, which IMO gives very bad advice on
puncture vine control.  To control it, it is best to remove the plants and
dispose of in heavy duty garbage bags).

Paul Wendt
                                                                           
                                                                           
             09/15/2007 04:32                                              
             PM                                                            
                                                                           
                                                                           
                                                                           
                                                                   Subject 
                                       Re: [wwbc] Puncture vine/Goathead   
                                       warning update on Stonebrook        
                                                                           
                                                                           

I originally posted the following at the beginning of August.  I went back
two weeks later and cleaned up the remainder of the plants at the top of
Stonebrook, in addition to two lush patches I saw growing into the road on
Elena between Purissima and Natoma (this was on/after the ice cream social
ride).

All of the plants are gone from these locations, and a check after last
Saturday's ride verified no regrowth, HOWEVER:

The danger of flats from thorns is still very real at the top of
Stonebrook, since is impossible clean up all the residual thorns.

I DID find a few thorns on the roadbed side of the curb on the west side of
Stonebrook (which I picked up...but probably didn't get them all).

On the east side of Stonebrook at the top, there a dirt jogging trail
separated from the road by a strip of dirt, and no curb.  I cleaned up
numerous plants there, but was unable to  get all the thorns, so there a
definite flat danger in stopping on either side of the road at top.
(Unlikely to pick up thorns from riding in the main part of the roadway
since car tires would be likely to pick up any which had scattered there.

...yet another reason to ride out in the roadway and not hug the curb.

If you don't know what puncture vine/goathead plants look like, please
follow the URLs below...knowing what it looks like is the best way to avoid
flats from it.

Paul Wendt


Paulw at enet.com  08/05/2007 11:19 PM

On Adrienne's ride today there was a regroup at the top of the hill on
Stonebrook.  I was delayed by a chain problem on Tepa, when I reached the
top I saw a huge patch of puncture vine on the right, and called out a
warning as the group took off.

Moments later, a rider had a flat, which he later described as a "thorn
flat".

It's my opinion that nearly all throne flats are from puncture vine, which
apparently the majority of cyclists don't recognize.  I know that I used to
attribute thorn flats to the obvious thorny tendrils of blackberries,
before I knew what puncture vine looked like.

Puncture vine, aka Goathead, Caltrops, Tribulus Terrestris, etc, produces
large beds of hundreds of thorns, each nicely designed to puncture bicycle
tires.  Once the plant has dried up, there's no obvious source of the
thorns...it's more like a bed of isolated tacks...except that the tacks are
little sharp thorns and aren't easily visible riding a bike or standing.

The infestation at the top of Stonebrook is a particularly bad spot
because is a natural regroup spot, where people stop at the edge of the
road.  There is at least a blacktop curb which keeps the vast majority (but
not all) off the roadway.

Checking for "Puncture vine" on Google gets the first hit as its use as an
herbal remedy, which IMO is primarily quackery, but whatever.

Wikipedia's entry on this is unusually incomplete, giving apparently good
references on debunking many of the herbal claims, and some info on
control/eradication of it...but the only reason given for *wanting* to
eradicate it is that it's a non-indigenous species!

Better reasons for eradicating is are:
"This is that obnoxious weed whose seeds are incredibly painful to step on,
get tracked into your carpet, puncture your bicycle tires, and have to be
pulled out of your pets' paws."

As is stated at:
http://www.naturesongs.com/vvplants/puncturevine.html
...which also has good pictures of what it looks like.


This website:
http://www.barbwired.com/andy/PunctureVine/
also has excellent pictures of what it looks like on the side of the road
(in Los Altos Hills, no less), and says:
"Puncture vine is the curse of bicyclists everywhere - if you pick up a
thorn in a tire, it's almost certainly from this plant."

Jobst Brandt weighs in at:
http://www.sheldonbrown.com/brandt/thorns.html
...which has no pictures, but some interesting comments about flats (as
well as some comments about Star Thistle, which isn't at all related to
Puncture vine).

Another picture and info on the weed at:
http://www.weedalert.com/weed_pages/wa_puncture_vine.htm

(Incidentally, at least 2 of the websites mention that the fruit/seed pods
have 1 to 4 seeds (with the sharp spines), while all or at least most of
the ones I've seen have 5).

I went back to Stonebrook after the ride and cleaned up maybe 2/3rd of the
area before exhaustion set in.  I will go back later and clean up more, but
a significant number of seeds will survive over the winter...eradication is
a multi-year task...so the hazard will persist for the foreseeable future.

There are also infestations on the other side of the road (roughly east
side) where there is a walking path.

This is Stonebrook at Prospect/Oak Knoll, roughly the top of the hill.

Paul Wendt