Goathead / Puncturevine Identification

(Tribulus Terrestris)

Early Stages - Stems & Leaves

First sprouts begin in early June & can continue sprouting through the summer. The plants have one large taproot. From the taproot, stems trail and form a mat-like cover over the ground. Leaves have a distinctive opposite pattern. 

Flowers

Thorns (seeds/fruits)

Bright yellow flowers have 5 petals that open after sunrise and close at night.

Habitat

The dreaded thorn, what goatheads are known and loathed for. The spiky thorns stick into tires, shoes, and paws. The thorns begin green and then turn a grey/tan as they separate and become hard as wood. The seeds inside the thorn stay dormant & viable for 3-7 years!

Goatheads are commonly found on disturbed sites, roadways, driveways, trails and parking areas, in overgrazed pastures, gardens and waste areas. Good soil moisture and warm temperatures are needed for germination, but after the plant is established it can tolerate dry soils due to its rapidly produced deep taproot.

Puncturevine / Goatheads are considered a class ‘B’ Noxious Weed in Washington State. For more information on WA State Noxious Weed designation, please CLICK HERE.