Family: Melastomataceae
An ornamental groundcover escaping cultivation and now sparingly naturalized. First documented as naturalized in 1958, it is becoming a pest on Kauaʻi, Oahu, Maui and Hawaiʻi Island. Native to tropical Africa, trailing tibouchina is a dominant weed in Australia and is considered a pest on other Pacific Islands.
Description and Dispersal:
- A creeping herb with the stems rooting at nodes and erect branches up to 7 in tall
- Velvety leaves ( 1-3 in long by 0.5-1 in wide) have 3 prominent veins and short reddish hairs
- Single bright purple flowers (2 in wide) with 5 pedals grow throughout ground cover; small round seeds
- Spreads with seeds and vegetatively from pieces
High Risk Traits:
- Naturalized: Hawaii (Kaua‘i, O‘ahu, Maui, Hawai‘i), Australia, Palau, Samoa.
- Weed: Agricultural weed (Africa, Australia) and environmental weed (Palau, Samoa), forming dense mats that exclude other species.
- Climate: Highly suited to tropical/subtropical climates.
- Shade tolerant: Establishes in forest understories.
- Growth habit: Creeping groundcover that can climb and smother other plants.
- Reproduction: Spreads vegetatively via fragments; intentionally planted by people.
- Response to mutilation: Fragmentation aids spread, complicating mechanical control.
Low Risk Traits:
- Habitat specificity: Demands moist conditions, limiting spread in drier areas.
- Physical/chemical traits: No spines, burrs, or evidence of toxicity.
- Seed dispersal: Not adapted for wind, bird, or external animal dispersal.
- Seed production: Fruit infrequently formed in cultivation.
- Herbicide control: Reported to be effectively controlled with chemicals.
