Considered very invasive and is on the Hawaii State Noxious Weed List. The Division of Forestry and Wildlife of the Hawaii Department of Land and Natural Resources has designated this species as one of Hawaii’s Most Invasive Horticultural Plants.
- Thorny shrub, up to 2 meters (6 ft) tall, with inch-long spines
- Bright, yellow flowers that smell faintly of coconut
- Native to Western Europe, introduced as food plant for sheep and as a “living fence”
- Forms dense, impenetrable thickets that allow nothing else to grow
- Seeds can remain viable in the soil for more than 30 years
- Deep roots help this plant survive fires, and fire helps the seeds sprout
- Produces copious seedpods
- Big Island – Infests higher altitude pastures and natural areas, including Hakalau and Puu Oo. BIISC does not target this plant, but will control in some locations. Plants are spreading down the Wailuku river toward Hilo and have recently been spotted at 3000’ elevation on Saddle Road. Landowners are asked to control gorse on their property wherever possible.