Family: Orchidaceae

Origin, Description & Uses
Dendrobium antennatum, commonly known as the green antelope orchid, is native to tropical regions of northern Australia, New Guinea, and nearby Pacific islands. This striking orchid is prized for its unusual, long, twisted green petals that resemble antelope horns, along with creamy white sepals and a decorative lip marked with purple veins. It grows as an epiphytic orchid, meaning it typically attaches to trees rather than rooting in soil, and produces upright canes with leathery leaves. Because of its exotic appearance and relatively easy cultivation in warm climates, the green antelope orchid is popular in ornamental horticulture and is frequently grown in gardens and as a potted specimen in tropical and subtropical areas.

Risks & Threats
On Oʻahu, the green antelope orchid is naturalized outside of cultivation. While valued as an ornamental, this species possesses traits that are cause for concern in tropical island ecosystems. As an epiphyte capable of producing numerous wind-dispersed seeds, it can spread beyond garden settings and establish on trees in natural or semi-natural areas. In sensitive habitats, it may compete with native epiphytic plants for space, light, and moisture. Because island ecosystems are particularly vulnerable to introduced species, the continued spread of Dendrobium antennatum could detrimentally impact native plant communities. Responsible planting, careful disposal of plant material, and monitoring of cultivated specimens are recommended to help limit further spread.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Grows in tropical climates (climate of Hawaiian Islands conducive to further establishment and spread)
  
• Naturalized on Oahu (Hawaiian Islands)
  
• Other Dendrobium species may be weedy
  
• Reproduces by seeds
  
• Forms natural hybrids with other Dendrobium species
  
• Self-compatible
  
• Seeds dispersed by wind, possibly water and intentionally by people
  
• Prolific seed production (potentially)

Low Risk Traits:

• No negative impacts documented to date (widely cultivated and valued for ornamental purposes)
  
• Unarmed (no spines, thorns, or burrs)
  
• Non-toxic
  
• Epiphytic habit may limit dispersal vectors to wind or intentional planting