Family: Zingiberaceae

White ginger is an invasive herbaceous plant native to the Himalayas and southwestern China. 

It was introduced to Hawaii by Chinese immigrants as an ornamental in 1888. Today, it is invasive on all the main islands. Particularly hard hit Kamakou Preserve, Kalopa State Park, Nahiku, Wailau Valley, and Puna and Kohala Mountains, Hawai’i.

White ginger is shade tolerant but also grows in the full sun. It rarely produces seed. Instead, rhizomes move into wet, shaded places to invade. It forms dense, single-species stands all from vegetative reproduction. Creeping horizontal plant stems or runners root at points along their length to form new plants. Because of the intense vegetative spread, mechanical removal is extremely difficult. A new stand can grow from one small rhizome piece. Machinery used to cut brush on roadsides is sometimes responsible for the spread. 

As a Category 12 invasive plant, white ginger is prohibited from trade in South Africa. It is known as an alternative host to the Banana Bunchy Top Virus (BBTV). 

Description and Dispersal:

• An herbaceous upright plant.
  
• Leaves 2-ranked, alternately arranged.
  
• Leaf margins entire, midrib prominent on the dorsal face. Smooth and glabrous on both surfaces, intense green, glossy.
  
• White flowers resemble butterflies.
  
• Reproduction is mainly vegetative, from parts of rhizomes, but also sexual.

High Risk Traits:

• Naturalized in Hawaii, Paraguay, and Philippines
  
• Agricultural and environmental weed (forms dense thickets, overwhelms low-growing plants)
  
• Congeneric weed (H. gardnerianum is a major invader)
  
• Shade tolerant
  
• Tolerates wide range of soil conditions
  
• Reproduces by vegetative fragmentation (rhizomes)
  
• Dispersed unintentionally by machinery and intentionally by people
  
• Tolerates mutilation and fire (recovers from rhizomes)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not allelopathic or parasitic
  
• Not toxic to animals or humans
  
• Not a fire hazard (succulent, low flammability)
  
• Requires specialist pollinators; seeds rarely formed in cultivation
  
• No prolific seed production; seeds not wind- or bird-dispersed
  
• No persistent seed bank reported
  
• Well-controlled by herbicides