Family: Boraginaceae
Origin, Description & Uses:
Phacelia tanacetifolia (fiddleneck, phacelia) is a fast-growing annual wildflower native to southern Nevada and Baja California in Mexico. It is valued for its delicate purple-blue flowers, fern-like foliage, and ability to attract pollinators such as bees, butterflies, and other beneficial insects. Because of its heavy nectar production, it is commonly planted in pollinator gardens, agricultural cover crop mixes, erosion control projects, and habitat restoration efforts. The species is also used as a green manure crop to improve soil health and suppress weeds in agricultural settings.
Risks & Threats:
Although Phacelia tanacetifolia is not currently known to be naturalized in Hawaii, it does possess traits that are cause for concern. The species grows rapidly, produces abundant seeds, and can thrive in disturbed environments, characteristics that may increase its ability to spread beyond cultivation under favorable conditions. Its adaptability and vigorous growth could potentially allow it to compete with desirable vegetation or alter local plant communities if it escaped into sensitive habitats. Ongoing evaluation is needed to determine whether this species could negatively impact Hawaii’s ecosystems, and caution is recommended when planting it near natural areas.
High Risk Traits:
- Naturalized in Europe, Australia and New Zealand
- Broad elevation range (> 1000 m distribution)
- Weedy growth; often escaping cultivation
- Contact may cause skin irritation or dermatitis
- Tolerates many soil conditions (potential to invade many habitat types)
- Annual (reproductive in <1 year)
- Small seeds dispersed as a seed crop contaminant
- Seeds dispersed in fur/hair of animals
- Forms a persistent seed bank
Low Risk Traits:
- Unarmed
- Fodder plant
- Non-toxic to animals
- Useful as a cover crop and green manure
- Used for nectar (bee keeping, wild bee conservation)
- Used in pest management mainly against aphids by attracting hoverflies
