Family: Solanaceae
Origin, Description & Uses
Solanum glaucophyllum (waxy-leaf nightshade) is native to South America, with a natural range extending from Bolivia and Brazil to northern Argentina. It is a semi-aquatic, shrubby perennial in the nightshade family (Solanaceae) that typically grows in wet or seasonally flooded habitats such as marshes, lake margins, and river edges. The plant is recognized by its thick, waxy, bluish-green leaves and clusters of small, star-shaped lavender to pale blue flowers, followed by round berries. While not widely cultivated as an ornamental, it has attracted attention in scientific research due to its unusual chemistry, including compounds that can affect calcium and vitamin D metabolism.
Risks & Threats
This species is known to contain toxic compounds that can cause serious health issues in grazing animals, including calcification disorders, making it a concern in agricultural and rangeland settings. It also has traits associated with invasive wetland plants, such as tolerance of saturated soils and potential to spread along waterways. Although Solanum glaucophyllum is currently not known to be naturalized in the Hawaiian Islands, it does possess characteristics that raise concern for tropical island ecosystems, where wet habitats are often vulnerable to aggressive plant spread and ecological disruption. Given these risks, caution is warranted, and selecting low-risk or native alternatives is recommended whenever suitable options are available.
High Risk Traits:
- Toxic to grazing animals (causes fatal calcification)
- Forms dense, dominant thickets
- Vegetative reproduction via rhizomes/gemmiferous roots
- Dispersed by water and birds
- Seeds survive bird gut passage
- Grows in pastures (unintentional spread risk)
- History of deliberate human introductions
- Naturalized in Japan (reported)
- Congeneric weeds are highly invasive
Low Risk Traits:
- No spines, thorns, or burrs
- No human toxicity or allergenicity reported
- Self-incompatible (requires cross-pollination)
