Sunday, September 9, 2012

Weed Identification: Goatheads or Stickers

Goatheads (Tribulus terrestris) are native to Southern Europe, Asia, Africa and Australia. Goatheads are also called stickers, sticker weed, bullhead, devil’s weed, and puncturevine. Goatheads are easily recognized by their prostrate growth form,

leaves with leaflets,

yellow flowers,

and stickers (Goatheads).

If you miss’em visually then they will stab you painfully in the fingers as you work your garden, or stick to your clothing and shoes. Goatheads are the primary reason local bicyclists must get “thorn proof” tires for riding on area trails and streets.

Goatheads have prostrate stems that radiate outward from one central point. Leaves are compound with smaller leaflets. Lemon yellow flowers form along the stems and fertilized flowers form fruits.  Fruits consist of several attached structures called nutlets (Goatheads).

Each nutlet is a single seed that becomes hard or woody when mature. Each seed has two sharp spines that easily penetrate skin, clothing, and soles of shoes. This attachment mechanism allows puncturevine seed to be spread great distances from the mother plant.

Goatheads have a short tap root located below the center of growth,
so digging it out is very easy but best to wear gloves seed bearing specimens. This method uses no chemicals and if done before seeds are present or while seeds are still green, virtually assures that you’ll remove all the Goatheads associated with that plant.

In sandy or moist soils simply grasp the puncturevine from its center point of attachment and pull.
In harder soils, use a shovel to go under the plant and cut the puncturevine off from its root. Then use the shovel to carry it (and all its stickers) and dump it in the trash or other container.

Contact Trees That Please Nursery for more information. 

Photos & Narrative By:
Stephen Sain
Staff Plant Physiologist

1 comment:

  1. Thank you for posting this.
    KKrattiger in eastern NM