Family: Fabaceae

Origin, Description & Uses
Lupinus microcarpus var. densiflorus (golden lupine, whitewhorl lupine) is native to western North America, with a range extending from California through Baja California in Mexico and into parts of south-central Arizona. It is an annual wildflower in the legume family that typically grows in open, sunny habitats such as grasslands, coastal scrub, and disturbed areas. The plant is recognized for its showy, upright flower spikes, which can display bright yellow to cream-colored blooms. Like other lupines, it has palmate leaves and produces seed pods typical of legumes. It is sometimes used in native plant gardens, habitat restoration projects, and pollinator-friendly plantings due to its attractive flowers and ability to support bees and other insects.

Risks & Threats
While valued for its ornamental and ecological qualities, this lupine has traits that may contribute to invasive behavior in suitable environments. As a nitrogen-fixing species, it can alter soil nutrient levels, potentially shifting competitive balances in native plant communities. It produces abundant seeds that may be readily dispersed and can establish in disturbed soils, raising concerns about its ability to spread beyond intended plantings. Although this species is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern, and which could detrimentally impact tropical island ecosystems. Careful consideration is recommended before use, and choosing a low risk or Hawaiian native alternative is encouraged when suitable options are available.

High Risk Traits:

• Can grow in >5 hardiness zones, and elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Can grow in subtropical conditions (possibly only at higher elevations)
  
• Other Lupinus species have become invasive weeds
  
• Potentially toxic to animals If consumed in large quantities
  
• Could be toxic to humans if consumed (unlikely scenario)
  
• Tolerates many soil types
  
• Able to form pure stands
  
• Self-compatible
  
• Able to reach maturity in <1 year (annual herb)
  
• Seeds dispersed passively by dehiscence and intentionally by people
  
• Small seeds could possibly be accidentally dispersed
  
• May form a persistent seed bank

Low Risk Traits:

• No reports of naturalization or negative impacts documented (may be due to limited planting outside native range)
  
• Although range extends into subtropical zones, this species is predominantly temperate and may only threaten higher elevation sites in the tropics
  
• Unarmed (no spines, thorns or burrs)
  
• Ornamental
  
• Beneficial to bees and other pollinators
  
• Not reported to spread vegetatively
  
• Herbicides provide effective control of Lupinus species
  
• Effectively controlled by mowing, grazing, cultivating