Family: Poaceae

Origin, Description & Uses
Guadua angustifolia, commonly known as guadua or Colombian thorny bamboo, is a large, fast-growing bamboo species native to Central and South America, particularly Colombia and surrounding regions. It is one of the largest New World bamboos, capable of reaching heights of over 60 feet, with thick, woody culms and distinctive thorny branches. Guadua is highly valued for its strength and durability, making it an important material for construction, furniture, fencing, and crafts. It is also used in erosion control, windbreaks, and agroforestry systems due to its extensive root system and rapid growth.

Risks & Threats
Although Guadua angustifolia is not known to be naturalized in Hawaii, it does possess traits that are cause for concern. Its vigorous growth, ability to form dense thickets, and potential to spread vegetatively could allow it to outcompete native vegetation and alter habitats if not properly managed. The species’ thorny growth can also create barriers to access and impact land use. Caution is recommended to ensure that it will not negatively impact Hawaii, and further evaluation is needed to determine its potential invasiveness under local conditions.

High Risk Traits:

• Elevation range exceeds 1000 m in tropical climates, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized in the Galapagos, and in several locations throughout Central and South America
  
• Vigorous, spreading species that may invade crops when grown in close proximity
  
• Armed at the base, lower branches strongly thorny with long straight thorns
  
• Potentially allelopathic
  
• Forms dense thickets in native range
  
• May produce viable seeds that can be dispersed by gravity, wind or people
  
• Able to coppice and resprout after cutting

Low Risk Traits:

• No reports of negative impacts where cultivated
  
• Non-toxic
  
• The most widely-grown and economically important bamboo in the New World
  
• A sympodial, or clumping bamboo
  
• Long time to reproductive maturity (35 years or more)
  
• Lack of seed production until possibly at the end of long life cycle would limit inadvertent dispersal